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• Critical moment (or Interval)
  41 bytes (5 words) - 20:18, 30 January 2014
• Two- or three-dimensional interpretation
  #REDIRECT [[Seismic data: two- or three-dimensional interpretation]]
  68 bytes (7 words) - 16:05, 21 November 2014
• Seismic data: two- or three-dimensional interpretation
  ...lts, channels, and other features of interest. There will always be faults or channels oriented at angles between 0° and 45° relative to the orientatio
  8 KB (1,280 words) - 17:33, 25 January 2022

Page text matches

• Dry hole
  ...[economics]] and technologies change, yesterday's dry hole may be revived (or a twin to it may be drilled) to yield today's successful well.
  322 bytes (52 words) - 13:44, 18 March 2019
• Interval transit time
  ...ic log, usually in units of μs/ft or μs/m. It is also seen as ''delta t'' or ''Δt''.
  205 bytes (40 words) - 20:03, 14 April 2014
• Biodegradation
  ...r methanogenic) biodegradation during migration or while in the reservoir, or at surface seeps, typically at temeraptures approximately less than 80°
  791 bytes (108 words) - 19:58, 25 June 2015
• AAPG Wiki:Privacy policy
  When making an edit or creating a new page on '''{{SITENAME}}''', contributors agree to these uses ...loads, for the purposes of tracking usage volume, diagnosing access issues or problems with the wiki server, and to administer the website.
  2 KB (333 words) - 15:37, 9 October 2013
• Bioturbation
  ...y and permeability. For instance, burrows filled with sand grains in a mud or clay unit could be conduits for fluid flow if connected. Bioturbation can o
  907 bytes (132 words) - 21:42, 18 September 2014
• Accumulation
  ...ot contain oil or gas. Accumulations, or pools, are traps that contain oil or gas.<ref name=Vincelette>Vincelette, R. R., E. A. Beaumont, N. H. Foster, 2 ...s smaller than the carrier bed. The seal pore throat breakthrough pressure or the distance to the spill point of the trap, whichever is less, determines
  1 KB (206 words) - 17:37, 27 January 2015
• Strike
  ...lly written as N25E, to distinguish it from dip, which is written 4S, 4SE, or 4 65SE.
  585 bytes (88 words) - 16:06, 11 September 2014
• AAPG Wiki:Governance documents
  ;Privacy policy: What one may or may not do with a user's data or behaviour. ;Copyrights: or '''Licensing''' — how people can use the content.
  3 KB (373 words) - 16:41, 31 July 2013
• Contour
  ...hores), differences between two seismic events or reflections (isochrons), or any variables that can be mapped.
  540 bytes (69 words) - 20:24, 27 March 2015
• Two- or three-dimensional interpretation
  #REDIRECT [[Seismic data: two- or three-dimensional interpretation]]
  68 bytes (7 words) - 16:05, 21 November 2014
• Asphaltenes
  ...remaining oil consists of saturates, aromatics, and nitrogen, sulfur, and/or oxygen (NSO) compounds.<ref name=Petersetal_2012>Peters, Kenneth E., David
  886 bytes (126 words) - 16:34, 25 June 2015
• AAPG Wiki:Wiki manager
  ...h static web content, but is more akin to the AAPG's nascent blog channel, or its membership engagement functions. ...ted, content-oriented, and technical. They don't have to be a geoscientist or even a petroleum professional, but it would help.
  2 KB (294 words) - 16:44, 22 July 2013
• Logging while drilling
  ...tion (look-ahead seismic profiles). Data can be transmitted to the surface or stored for later retrieval.
  2 KB (206 words) - 21:17, 3 December 2015
• Free water level
  ...m. It produces water only. Zero [[buoyancy pressure]] exists at this level or below.
  525 bytes (76 words) - 14:40, 8 September 2014
• Liptinite
  ...ured (e.g., [[resinite]], [[sporinite]], or [[cutinite]]) and unstructured or amorphous liptinites, sometimes called [[amorphinite]], can occur.<ref name
  788 bytes (102 words) - 19:51, 25 June 2015
• Trap systems: structural, stratigraphic, and fluidic
  The proposed classification scheme divides [[trap]]s into three main groups or systems, based on the controlling geologic element that created the trap: ...ure|syndepositional]] [[deformation]] or displacement of [[reservoir]] and/or [[seal]]ing units
  3 KB (405 words) - 17:44, 12 April 2022
• AAPG Wiki:General disclaimer
  ...of the Content and shall not have any liability whatsoever for any direct or consequential damages resulting from the use of any information obtained th ...this Web site or cited, used or discussed in AAPG copyrighted publications or in presentations at events associated with AAPG.
  4 KB (654 words) - 18:31, 2 August 2013
• Sidetrack
  ...entionally or may occur accidentally. A [[multilateral well|multilateral]] or [[multilevel well]] will have multiple intentional sidetracks drilled to pr
  1 KB (191 words) - 19:41, 3 March 2016
• Hydrocarbon column
  This term refers to a vertical measure of the reservoir or trap containing hydrocarbons.
  165 bytes (22 words) - 19:51, 14 April 2014
• Fault trap regime
  ...ows definitions and examples for the classes and subclasses of these traps or trapping elements. ...ne or more sides by normal faults. Rotation traps hydrocarbons along edges or in corners.
  5 KB (740 words) - 16:04, 13 April 2022
• Sand peel
  ...pture of details in sedimentary features for analysis away from the field, or for use in teaching.
  2 KB (239 words) - 19:40, 9 September 2014
• Deasphalting
  ...deasphalting is achieved by adding light hydrocarbons, such as [[pentane]] or [[hexane]], to the oil. A similar process can occur in nature when [[methan
  864 bytes (120 words) - 19:55, 25 June 2015
• AAPG Wiki:Users
  ==User types or roles== | '''Root''' || 3 || Login || No || All || The person or people who can log into the server and edit LocalSettings.php
  2 KB (294 words) - 16:01, 6 August 2013
• Pore systems
  ...ned [[sandston]]e might be classified as having intergranular mesoporosity or a [[limestone]] as having vuggy macroporosity. |Mega/macro || Clean, coarse sandstone or [[carbonate]] [[grainstone]] ||
  3 KB (442 words) - 13:52, 4 April 2022
• Types of diagenetic traps
  [[Diagenesis|Diagenetic]] traps occur in two basic categories: early or near-surface traps and late-burial traps. Early or near-surface diagenetic traps are created by the following:
  2 KB (294 words) - 21:01, 4 February 2022
• Hiatus
  A break or discontinuity in a process. An [[unconformity]] is the physical representa
  217 bytes (28 words) - 20:48, 25 August 2014
• Fluid-composition trap regime
  Fluid-composition traps are controlled by the physical or chemical properties of the trapped fluids themselves. The [[Wikipedia:Solub ...[[asphalt]], [[tar]]) or solid hydrocarbons ([[albertite]], [[gilsonite]], or [[grahamite]]). || ''Tar Seals'' || ''Bacterial degradation;'' Updip tar se
  3 KB (402 words) - 16:31, 13 April 2022
• Syncline
  ...ts such as tilting or faulting, among others, a fold should have its crown or crest as the [[anticline]] and the trough of its structures as the syncline ...olded. This is the best term used to describe it rather than “downward arc or trough of a fold” this is because due to events when strata has been over
  3 KB (505 words) - 15:58, 21 March 2019
• Fold
  ...[[uplift]]. Folds are expressed in [[seismic reflection profile]]s as one or more regions of dipping reflections ([[dip]] domains) that correspond to in ...hether or not the thickness of stratigraphic layers changes in dip domains or across axial surfaces.
  3 KB (495 words) - 15:09, 18 January 2016
• Petroleum system identification
  ...leum system. An oil or gas seep, a show of oil or gas in a well, or an oil or gas [[accumulation]] demonstrates the presence of a petroleum system.
  2 KB (298 words) - 18:35, 25 January 2022
• How different structural philosophies govern techniques
  ...al geology, and various university departments and E&P companies favor one or another in their courses and approaches to problem-solving. The major appro * Detailed geometric and/or kinematic studies
  3 KB (422 words) - 20:17, 3 February 2022
• Paleogeography and prospect identification
  ...l analysis of clastic depositional systems#Shoreline deposits|shorelines]] or [[reef]]s. Mapping thickness of reservoir-quality rocks is also useful for ...ial for containing reservoir rocks, i.e., [[Third-order sequences|lowstand or highstand]], using biostratigraphic markers and regional correlation surfac
  4 KB (491 words) - 14:27, 21 March 2022
• Paleontologic data
  ...tratigraphic correlation and age determination|biostratigraphic analysis]] or in a geographic array for [[Paleoenvironmental analysis|evaluating paleoenv * Records of species present or absent
  2 KB (268 words) - 15:18, 31 January 2022
• Paleocurrent
  [[file:1024px-WaveRipple.JPG|thumb|300px|Wave ripple or symmetric ripple, from Permian rocks in Nomgon, Mongolia. Photo by [https:/
  372 bytes (51 words) - 22:00, 17 March 2015
• Isochron
  Time interval (or isotime or isochron) maps are commonly used for interpreting changes in thickness betw
  1 KB (135 words) - 14:13, 24 November 2015
• Bend
  ...]], in which the well path is designed to change orientation from vertical or high-angle to horizontal.
  1 KB (173 words) - 15:33, 16 March 2016
• Build rate
  ...ough the bend (curve) from vertical or high-angle to the desired low-angle or horizontal attitude.
  1 KB (174 words) - 19:33, 3 March 2016
• Molecular parameter data for oil–oil and oil–source rock correlations
  ...e or on the relative or absolute abundance of specific molecules in an oil or a [[source rock]] extract. ...can be obtained. In addition to correlating an oil directly to another oil or to a source rock extract, certain molecular parameters can be used to estim
  2 KB (294 words) - 21:02, 15 February 2022
• Basement
  Basement is rock below a sedimentary cover, often [[igneous]] or metamorphic. It is generally not of interest in exploration for oil and ga
  264 bytes (40 words) - 15:52, 10 March 2016
• Limitations of quantitative fault seal analysis
  ...ale]] sequences. It is not applicable to massive [[carbonate]], [[chert]], or sandstone reservoirs. It has yet to be tested in interbedded shale–carbon ...th which a seal can be risked is thus much greater in a production setting or mature basin than it is in a frontier setting.
  3 KB (398 words) - 17:35, 29 March 2022
• Extended-reach wells
  ...refers to wells restricted to a platform or pad (because of environmental or economic contraints) that are attempting to access reserves at a significan
  1 KB (186 words) - 19:42, 3 March 2016
• AAPG Wiki:Ease of use
  ...erences, journals or ability to cut and paste an equation macro into excel or other applications *'''Printing''' - make it easy to print entire articles or selected subsets
  2 KB (266 words) - 15:49, 6 August 2013
• Trap classification levels
  ...eologic element || Dominant control of the trap—structural, stratigraphic, or fluidic. ...sses? If the trap is fluidic, was closure formed by pressure, temperature, or chemical processes?
  5 KB (665 words) - 18:47, 12 April 2022
• Petroleum system naming
  A unique designation or name is important to identify a person, place, item, or idea. As geologists, we name rock units, fossils, uplifts, and basins. The | A positive [[Oil-oil and oil-source rock correlation|oil-source rock]] or gas-source rock correlation
  3 KB (367 words) - 18:35, 25 January 2022
• Fracture traps
  ...he structural system because fractures are a result of [[deformation]] and/or displacement and therefore are structural in nature. ...ractured rock or by change from open, permeable fractures to cement-filled or narrow-aperture, low-permeability fractures.
  3 KB (461 words) - 16:04, 13 April 2022
• Quantitative paleoenvironmental analysis
  ...into clusters. The results of the cluster analysis show faunal groupings, or ''biofacies'', which are often characteristic of specific environments. [[: ...r geologic data to determine or evaluate specific paleoenvironmental zones or settings.
  4 KB (493 words) - 20:00, 31 January 2022
• Buoyancy pressure
  Buoyancy is the tendency for a body (or a drop of immiscible fluid) to float or rise when submerged in a fluid of greater [[density]]. Where two immiscible ...re#Capillary pressure concepts|capillary effect]]s—such as a bottle, lake, or cave—the different fluids exhibit a sharp, flat interface.
  4 KB (596 words) - 18:37, 17 February 2022
• Selecting a surficial geochemistry survey method
  ...er area, to high-grade previously defined exploration leads and prospects, or to determine the type of petroleum (i.e., oil vs. gas) likely to be encount ...cal methods have previously been used successfully in the area of interest or in a geologic analog area?
  6 KB (809 words) - 17:05, 25 January 2022
• Fossil assemblage
  Fossil assemblages, or faunal assemblages, are simply groups of fossils found together in strata.
  484 bytes (58 words) - 20:11, 12 March 2015
• Surficial geochemical exploration principles
  ...xploration for petroleum is the search for chemically identifiable surface or near-surface occurrences of hydrocarbons and their alteration products, whi * Hydrocarbon seepage can be active or passive and is visible (macroseepage) or only detectable analytically (microseepage).
  5 KB (687 words) - 19:23, 24 January 2022
• Surficial geochemistry: limitations and uncertainties
  ...very real and can significantly affect the [[economics]] of an exploration or development program, the user must be aware of limitations associated with * False seep anomalies can be caused by reworked [[hydrocarbon]]s and/or reworked [[source rock]]s.
  3 KB (418 words) - 21:19, 24 January 2022
• Tertiary migration
  ...rocarbon migration|Migration]] to the surface, either from a [[reservoir]] or [[source rock]]. Also called dismigration.
  440 bytes (58 words) - 21:47, 25 June 2015
• Trap
  * '''Trap seal'''—an impediment or barrier that interferes with hydrocarbon [[migration]] from the reservoir. ...en reservoir and seal, or (2) boundaries between fluids, such as oil–water or gas–water contacts. Temperature can also control a trap boundary as displ
  4 KB (614 words) - 17:02, 12 April 2022
• Type IV kerogen
  ...ee common source rock evaluation errors made by geologists during prospect or play appraisals]: AAPG Bulletin, vol. 93, issue 3, pp. 341-356.</ref>]] ...in thermally immature rocks; dominated by organic matter that was recycled or extensively oxidized during deposition. Sometimes the type IV pathway is no
  1 KB (185 words) - 21:11, 6 July 2015
• Fold trap regime
  ...p. 219-235.</ref> || rowspan = 2 | ''Local anticline'' || ''Fault bounded or cross faulted'' || ''Relief, symmetry, internal faulting, internal geometry ...rom the horizontal in one direction only and are not a part of a anticline or syncline.<ref name=ch02r11>Rittenhouse, G., 1972, [http://archives.datapage
  6 KB (742 words) - 14:42, 13 April 2022
• Structural maps and cross sections
  ...ect, regardless of local structural style, level of structural complexity, or exploration maturity: ...tratigraphic thickness variation or has behaved in a [[Ductility|ductile]] or compactive manner during [[deformation]].
  4 KB (504 words) - 14:17, 2 February 2022
• How to use the trap classification scheme
  ...hic, structural, or fluidic traps. But many traps are a combination of two or three geologic elements. In these traps, basic trapping elements occur in c
  1 KB (191 words) - 18:46, 12 April 2022
• Pore system fundamentals
  ...-D pore system geometries found in intergranular, intercrystalline, vuggy, or fractured rocks. ...-D pore system geometries found in intergranular, intercrystalline, vuggy, or fractured rocks. Copyright: Coalson et al.;<ref>Coalson, E. B., S. M. Gools
  3 KB (388 words) - 13:52, 4 April 2022
• Basin-fill and trap analysis
  ...h. Basin-fill analysis is looking for [[Stratigraphic trap|stratigraphic]] or [[combination trap]]s by combining [[paleogeography]] with the results of t
  1 KB (189 words) - 18:53, 4 February 2022
• Fracture trap regime
  ...otally mineralized by postfracture cements, typically calcite, [[gypsum]], or silica. | ''Nonmineralized fracture''; Contains no postfracture cements or minerals.
  7 KB (895 words) - 16:04, 13 April 2022
• Migration pathway map construction
  ...or [[Cross-leaking faults|cross-leak]] and [[Dip-sealing faults|dip-seal]] or [[Dip-leaking faults|dip-leak]]. ...s real JLLPs, areas of cross-seal or cross-leak, and areas of [[dip]] seal or dip leak
  3 KB (405 words) - 18:19, 29 March 2022
• Archie equation
  * Non-Archie pore geometries (i.e., not intergranular or intercrystalline) (See [[Pore systems]].) ...stments. The table below lists the five variables and methods for deriving or estimating them.
  5 KB (703 words) - 13:52, 5 April 2022
• Fracking
  ...fluid is lifted to the surface of the back is often called produced water or flowback water. In practice, the withdrawal of fracking fluid to the surfac ...t least 2 times until water is considered feasible to naturally evaporated or removed kesaluran common disposal.
  3 KB (484 words) - 21:18, 27 March 2019
• Structural styles: data and techniques for evaluation
  ...vidual structures generally have good [[strike]] continuity and poor depth or [[dip]] continuity. Hence, in any newly discovered thrust belt, these same If and when one or more structural styles are ascribed to an area, certain of the structural t
  3 KB (420 words) - 20:13, 3 February 2022
• Erosional trap regime
  ...boundaries occur along contacts between erosional surfaces and underlying or overlying [[reservoir]s. ...and bottom seals beneath the unconformity. || Regional subcrop; Uniformly or gently dipping reservoir bed beneath an unconformity. Top seal is provided
  5 KB (588 words) - 16:13, 13 April 2022
• Kerogen type and quality: visual assessment
  ...g transmitted light through a microscope to determine its form (structured or amorphous) and origin. Structured kerogens include woody, herbaceous, [[The ...kerogen in a sample derived from cuttings composites or core (conventional or sidewall). For example, a visual estimate of kerogen type might be stated a
  2 KB (300 words) - 18:17, 9 February 2022
• Interpreting hydrocarbon shows
  ...indications of hydrocarbons—seen in [[drilling fluid]]s, cuttings, cores, or formation tests—may be of several types:<ref name=ch09r55>Schowalter, T. | Continuous phase || Trapped oil or gas || A slug or filament of oil or gas with a continuous connection through the pore network of a rock
  8 KB (1,130 words) - 17:09, 5 April 2022
• Pressure trap regime
  ...[[pressure gradient]]s to [[Overpressure causes|overpressure]]s can create or destroy [[Pressure compartment seals|pressure seals]] and create isolated [ | Tilted oil–water contacts; Boundary defined by tilted oil–water or gas–water contact. || colspan = 2 | Hydrodynamic traps; Tilted hydrocarbo
  3 KB (331 words) - 16:30, 13 April 2022
• Natural-gas liquids
  ...at natural-gas processing plants are called [[natural-gas plant liquids]] or [[liquefied petroleum gasses]] and consist primarily of ethane, propate, bu ...o obtain. The total amounts of NGL, or of the lease condensate production, or both, are commonly reported as part of the [[crude oil]] production, and wh
  4 KB (549 words) - 16:31, 25 June 2015
• Reservoir system
  ...uilibrium with a [[free water level]] (zero buoyancy pressure). It has one or more containers and is located below a seal. ...ble rock 100% saturated with water. It has one or more containers that may or may not be shared with a reservoir.
  4 KB (579 words) - 14:34, 1 April 2022
• Diagenetic impact on traps
  ...acies or paleostructure. However, if [[diagenesis]] does not follow facies or paleostructure, then the exploration and exploitation risk increases becaus
  2 KB (297 words) - 21:06, 3 February 2022
• Preparing to go to the field
  ...ning about the formations in the study area—even driving the seismic lines or flying over the area. ...in the necessary permissions from owners and/or authorities to access land or airspace. It's a good idea to get permissions in writing and carry them wit
  5 KB (730 words) - 22:36, 1 February 2022
• Seal failure prediction
  ...lace through micropermeable lithologies ([[Micropermeable seal leakage]]), or gas is diffused ([[Diffusive seal leakage]]). The most likely mechanism is ...ure|fracturing]] during [[deformation]] or by cumulative micropermeability or [[Diffusive seal leakage|diffusive seal loss]].
  4 KB (571 words) - 18:06, 1 February 2022
• Agglutinated microfossils
  ...e of stratigraphically significant agglutinated microfossil: agglutinated, or arenaceous, foraminifera. ...orms may include silt or sand grains, [[glauconite]], [[sponge spicule]]s, or even other foraminiferal tests. Some species are highly selective in the ma
  4 KB (468 words) - 15:16, 31 January 2022
• Diagenetic trap regime
  ...to postdepositional diagenetic processes, which can create new reservoirs or new seals. ...d_flow_characterization#Dissolution_and_associated_processes|dissolution]] or [[Carbonate_reservoir_models:_facies,_diagenesis,_and_flow_characterization
  5 KB (645 words) - 16:14, 13 April 2022
• Functions of a petroleum landman
  ...the case of an independent landman, the functions vary depending upon his or her area of specialization. Generally, these functions can be divided into ...ades, well trades, joint venture agreements, creation of partnerships, and/or acquisition of entities.
  5 KB (759 words) - 19:25, 19 January 2022
• EMD Tight Oil & Gas Committee Annual Reports
  ...l session focused on the committee’s area of interest at an annual, region or section meeting of the AAPG; * (c) technical paper presented at an oral or poster session of an AAPG meeting, with slide deck published on Search and
  3 KB (417 words) - 20:29, 20 September 2022
• Gravity data processing
  ...ues over deep ocean basins because of variations in the crustal thickness, or ''[http://www.hko.gov.hk/education/edu06nature/ele_isostasy_e.htm isostasy] * Upward or downward continuation—a process that attenuates or deattenuates data to simulate what might be observed at different vertical
  4 KB (519 words) - 14:16, 31 January 2022
• Predicting hydrocarbon recovery
  ...l ([http://www.enggcyclopedia.com/2012/03/gas-oil-ratio-gor/ gas-oil ratio or GOR]). For example, if a well has a GOR of 1,000, then B_oi = 1. ==Estimating recoverable volume of oil or gas==
  5 KB (691 words) - 17:10, 5 April 2022
• Postprimary migration and compositional changes
  ...tion path; (2) mixing [[migration]] streams from two or more source rocks; or (3) precipitation of [[asphaltenes]] and other high-molecular-weight compou ...mum probability of interactions. However, if the petroleum moved as a slug or filament, contact with elements that could alter its composition would be m
  5 KB (694 words) - 15:17, 14 February 2022
• Phases of a seismic project
  ...ruined by sloppy acquisition methods. Common culprits are poor positioning or cabling information (i.e., which receivers are live for which shots). For m ...n acquisition footprint. One should avoid footprints because they can mask or confuse geologic patterns in the data.
  3 KB (455 words) - 22:00, 25 January 2022
• Special field techniques
  ...ds or lithologic horizons on well logs, separated by distance, as the same or correlative interfaces in the earth), particularly when significant distanc ...ing, thick vegetation, and/or thin [[alluvial]] cover. A seismic shot hole or water well drilling rig can be strategically positioned for collecting such
  3 KB (412 words) - 22:40, 1 February 2022
• Maturation
  ...ecting its [[Thermal history|thermal]] and [[burial history]]. This change or maturation is measured and can be combined with quality and richness data t ...ed from most maturation indices is dependent on the type of organic matter or material being analyzed.
  3 KB (421 words) - 18:26, 9 February 2022
• Reservoir drive mechanisms
  * Rock or compaction drive ...reservoir and has a much larger volume than the reservoir (about 10 times) or is in communication with surface recharge. A strong water drive is more eff
  7 KB (1,052 words) - 18:45, 1 April 2022
• Selling a structural play
  ...to be accepted, we must construct a coherent explanation of the mechanics or tectonics responsible for creating the play. Such explanations can be any o * Appropriate physical and/or mechanical models that clarify the structure's development
  5 KB (738 words) - 15:58, 2 February 2022
• Drilling problems
  ...Typically, a dogleg is caused by a change in the [[dip]] of the formation or by a change in the weight applied to the bit. Severe doglegs can result in ...ally form as a result of dog legs. A ''key seat'' is formed when a channel or groove is cut in the side of the hole, parallel to the axis of the hole. Th
  5 KB (732 words) - 21:18, 19 January 2022
• Economics: fundamental equations for oil and gas property evaluation
  ==Profit or loss equation== ...of any business venture can be expressed as the difference (either profit or loss) between revenue and costs. In other words,
  6 KB (842 words) - 19:26, 19 January 2022
• Paleogeography
  ...]. Once an [http://en.wiktionary.org/wiki/isochronous isochronous] surface or coeval interval is identified, paleogeography can be reconstructed by integ
  2 KB (242 words) - 15:48, 1 March 2022
• Scientific method
  The logic sequence, or ''scientific method'', has been the basis of scientific work since the time # Test predictions by observing occurrences or nonoccurrences of the predicted phenomena.
  3 KB (380 words) - 14:31, 18 February 2022
• Laurentia
  ...million years or so. Continents can grow when two plates collide, welding, or accreting, the two pieces together. Continents also grow when [[oceanic cru
  2 KB (248 words) - 22:12, 3 December 2015
• Predicting preservation and destruction of accumulations
  ...Other accumulations, however, may be destroyed. Several processes deplete or destroy hydrocarbon accumulations. In many prospects it is not enough just ...lossary.oilfield.slb.com/en/Terms/n/natural_gas.aspx gas] has been diluted or altered so that [[accumulation]]s are no longer economic.
  5 KB (782 words) - 22:36, 31 January 2022
• Designing a surficial geochemical survey
  * Anticipated target size and shape of the anomaly (or geologic target) * Ability to sample along (and/or between) key [[seismic line]]s
  6 KB (826 words) - 17:33, 25 January 2022
• Pore system shapes
  * [[Bored or burrowed]] | Pores are irregularly distributed and can be either poorly or very well connected
  4 KB (528 words) - 13:53, 4 April 2022
• EMD Tight Oil & Gas Committee
  ...d and developing plays in U.S. and international basins. Tight oil and gas or “shale” resources have been the focus of extensive development over the ...nual and commodity reports as needed; stand-in for the chair at leadership or other call-ins/meetings when the chair is unavailable; assist with other co
  4 KB (570 words) - 20:56, 6 April 2021
• Structural lead and prospect delineation
  * Storage capacity (structural degradation or enhancement effects) * Deliverability (structurally induced enhancement or degradation of [[permeability]])
  4 KB (511 words) - 18:50, 3 February 2022
• Scientific method: application to exploration
  | 6 || Accept, modify, or reject the hypothesis || Drilling another wildcat well Promoting a well to ...oblem (objective) of an exploration effort is to find large amounts of oil or gas cheaply.
  6 KB (808 words) - 15:30, 18 February 2022
• Source rock
  A '''source rock''' is a rock that is capable of generating or that has generated movable quantities of [[hydrocarbon]]s. ...rock is present. If so, then we ask, “How good is it? Will it generate oil or gas? Has it generated hydrocarbons already?” To answer these questions, w
  4 KB (569 words) - 21:38, 4 February 2022
• Hydrocarbon migration
  ...[Tertiary migration]] occurs when petroleum moves from one trap to another or to a seep.<ref name=Petersetal_2012>Peters, Kenneth E., David J. Curry, and ...he hydrocarbons laterally up [[dip]] through underlying beds to a [[trap]] or spill point. Lateral migration is also facilitated by meteoric groundwater
  6 KB (865 words) - 14:33, 6 April 2016
• Combination trap
  ...the trap belongs to one system or another is quite blurred. Traps with two or more trapping elements are called combination traps. ...e classified informally as (1) a hydrodynamically modified anticlinal trap or as (2) a hydrodynamic/anticlinal trap.
  4 KB (538 words) - 18:47, 12 April 2022
• Diagenesis
  ...of a sediment after deposition.It can have important effects in decreasing or enhancing [[porosity]] and [[permeability]].
  691 bytes (74 words) - 16:13, 22 October 2014
• Hydrofractured seal leakage
  ...enough, the sum of the [[capillary pressure]] and fluid pressure can equal or exceed the pressure needed to [[fracture]] the rock. The result is natural ...of a [[hydrocarbon column|petroleum column]] whether the seal fails during or after charging. Leakage in deeply buried accumulations occurs only where ge
  5 KB (679 words) - 17:11, 1 February 2022
• Trip
  ...le - to change a bit for example, either because the old one is worn down, or because the well is about to enter a zone whose conditions require a differ
  450 bytes (82 words) - 13:57, 12 March 2019
• AAPG Wiki:Main Page
  ...age, you will need a large image with not too many colours, low saturation or low brightness. It's easy to tweak text colour, link colour, etc if needed. ...strike the best balance between filesize (speed) and quality. For line art or other 'flat' images, use PNG for best results.
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• Static oil pressure gradient estimation
  ...]], and [[Wikipedia:Pressure|pressure]]. [[Oil and condensate analysis|Oil or condensate density]] can be estimated to useful accuracy if stock tank [[AP ...tion_fig5-7.png|Figure 1]] to determine oil density. If the GOR is unknown or if there is no dissolved gas in the oil, use the 0 line.
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• Suggested pages
  ** [[Historic plays or fields]] ...t have enough material to properly discuss a topic and need to be added to or completed.
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• AAPG Wiki:Copyrights
  For any reuse or distribution, you must make clear to others the license terms of this work. If you want to import text that you have found elsewhere or that you have co-authored with others, you can only do so if it is availabl
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• 3-D seismic data views
  ...n several ways. Vertical cuts through the data cube are called '''lines''' or '''sections'''. For marine surveys, [[in-line]] is the direction of boat mo Horizontal or subhorizontal cuts through a seismic data cube are called horizontal slices
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• Fractured membrane seal leakage
  ...:Deformation_(mechanics)#Strain|strained]], such as in stratigraphic traps or broad, gentle folds. Even relatively intact, thick seals may be fractured a ...deformation can be evaluated empirically by examining nearby accumulations or outcrops in similar tectonic settings.
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• Phi scale
  ...then calculated. Mean grain size can be expressed in either the millimeter or phi scale, but sorting must be expressed in the phi scale to maintain a sor
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• Structural exploration: location selection
  ...ons. This approach becomes critical as the structural complexity increases or the structural play concept becomes more sophisticated. ...which it is more appropriate to select a location based on technical needs or data quality rather than optimizing the economic success of the first well.
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• Abnormal hydrostatic pressure
  * [[Reservoir_quality#Compaction|Rock compaction]] or [[Rock dilation|dilation]] Abnormal pressures develop when fluid is unable to move into or out of the local [[Pore system fundamentals|pore system]] fast enough to ac
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• Migration rate calculation
  The rate of [[Hydrocarbon migration|migration]] for [[oil]] or [[natural gas|gas]] can be estimated using [[Fluid flow fundamentals|Darcy' ...cedure for calculating the [[Hydrocarbon migration|migration]] rate of oil or gas is outlined in the table below.
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• Underpressure causes
  Underpressure can be caused by [[burial]] or [[heat]] decrease. ...y [[impermeable]] rocks, it becomes underpressured by burial when faulting or downwarping occurs.
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• Displacement pressure estimation
  ...cury injection measurements || [[Overview of routine core analysis|Cores]] or [[Mudlogging: drill cuttings analysis|cuttings]] | Pore-size distribution || [[Thin section analysis|Thin sections]], cores, or cuttings
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• Inertinite
  ...maceral]] group composed of inert hydrogen-poor organic matter with little or no petroleum-generative potential. Type IV [[kerogen]] is dominated by iner
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• Seismic data: building a stratigraphic model
  The problem addressed in seismic modeling, or simulation, is calculating the seismic response ([http://wiki.seg.org/wiki/ Depth-dependent velocity and density models are needed to identify events or to create a synthetic seismogram. Velocity information can come from a vari
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• Structural exploration workflow
  ...-4.png|Figure 2]]) are most important to perform early in a frontier basin or play. More detailed analyses requiring more detailed data (right half, [[:f
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• Province, basin, system, play, and prospect
  ...in or Paris Basin. The Zagros [[fold]] belt could be a structural province or a petroleum province, not a basin. ...edimentary rocks. However, the moment petroleum is generated, biologically or thermally, a petroleum system is formed.
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• Oil-oil and oil-source rock correlation
  Correlations are comparisons of (1) oils with other oils or (2) oils with [[source rock]] extracts to determine whether a genetic relat ...osing [[migration|migration pathways]] from kitchen areas to new prospects or plays
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• Seepage activity and surficial geochemistry
  ...iles. Active seepage occurs in basins now actively generating hydrocarbons or that contain excellent migration pathways. These seeps are easily detected ...evels of hydrocarbon seepage may only be detectable near major leak points or below the zone of maximum disturbance.
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• Normal hydrostatic pressure
  ...rticle, where the fluid state (liquid or gaseous) is important, the state (or phase) is specified.
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• Energy Minerals Division
  ...helping to organize or support local society meetings, regional, national or international meetings, symposia, workshops, short courses, and field trips
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• The gravity method
  ...nding on the instrument. Other factors, such as errors in positioning data or the movement of the meter, usually cause larger uncertainties in the observ ...mmediate interest) is usually important to acquire, although other surveys or government data may be available for this purpose.
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• Relative permeability
  ...lity. Relative permeability can be expressed as a number between 0 and 1.0 or as a percent. Pore type and formation [[wettability]] affect relative perme ==Why k_ro or k_rg is less than k_ab==
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• Meteoric diagenesis
  Meteoric [[diagenesis]] is the modification of deposits at or near the surface in the [[phreatic]] and [[vadose]] zones.<ref name=Scholle
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• Top and fault seal evaluation
  * Presence or absence of [[hydrocarbon]]s ...ulations. Assessment of percent fill without the ability to risk seal (top or fault) is reduced to a statistical guessing game. They control the vertical
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• Hydrodynamics
  Hydraulic head (H_w) is the height or elevation above a given subsurface point at which a column connected to a b * H_w = height above P (ft or m)
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• Carbonate
  ...and XF methods|X-Ray Diffractometry]]. Carbonates more rich in calcite and/or aragonite are called [[limestone]]. Carbonate rocks composed mainly of the
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• Basin framework
  The particular study area, whether only a part of a basin or an entire basin itself, should be identified on a large-scale geographic ma ...ploration for hydrocarbons within each of these subbasins. We can prepare (or locate) a map showing total sediment thickness and the distribution of hydr
  4 KB (518 words) - 16:42, 18 February 2022
• Structural domains
  ...region with similar structural properties (e.g., similar [[fold]] vergence or style, shortening, uplift, faulting style, etc.). * Satellite imagery and/or aerial photography (See [[Remote sensing]].)
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• Magnetics: total intensity and residual magnetic maps
  ...al intensity maps show larger scale geologic features, such as basin shape or anomalous rock types deep within the basement. ...of techniques, including running averages, polynomials, low-pass filters, or [http://wiki.seg.org/wiki/Dictionary:Upward_continuation upward continuatio
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• Offshore exploration and exploitation
  ...ect searching for the resources using geophysical methods: Magnetic survey or register, gravimetric survey, and seismic survey. === Magnetic survey or register ===
  5 KB (708 words) - 22:00, 10 April 2019
• Hydrocarbon column: calculation of maximum height
  or, in mixed units, * ''h'' = thickness of the hydrocarbon column, ft or m
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• Hydrodynamic traps: mapping
  ...lp outline areas where hydrodynamic gradients may have created, destroyed, or modified traps. # Look for [[permeability]] barriers or hydrocarbon-free water levels using pressure-depth plots.
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• Quantitative biostratigraphy
  ...rray of data points, a preferred overall correlation can be defined by one or more line segments. Points falling on the line(s) of correlation are interp ...are based on the sequence of events and not on the stratigraphic intervals or distances between them.
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• Midale seal capacity and trap type
  ...lumn of oil shared by Weyburn and Steelman. Weyburn is a hydrodynamic trap or a combination hydrodynamic–[[stratigraphic trap]]. ...fferent pore types and pore geometries. For an explanation of each diagram or chart see Chapter 9 in ''Exploring for Oil and Gas Traps''.
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• Cracking
  ...molecules break apart into smaller molecules during burial [[maturation]] or in a refinery. [[Kerogen]] in source rocks and oil in reservoirs are cracke
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• Subregional and local pressure compartments
  ...der) [[pressure compartments]] can be found within normal pressure regimes or [[regional pressure compartments]]. ...outside the bioherm. The bioherm, then, is a pressure compartment that may or may not be abnormally pressured. Other geological features that may form lo
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• Microbial gas
  Also called marsh gas or biogenic gas; typically greater than 99% [[methane]] produced by methanogen
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• Remote sensing
  * Side-looking airborne radar (SLAR) and/or sonar ...ltitude data or by using a contractor as an intermediary for obtaining and/or processing the imagery
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• Procedure for geometrical analysis
  ...itional sequences]], [[Systems_tracts_and_trap_types|systems tracts]], and/or [[Hierarchy of sequences|parasequence]]s. Recognizing these correlation fea ...ized by onlap of strata deposited in fluvial, deltaic, or nearshore marine or peritidal environments.<ref name=ch21r48>Weber, L. J., J. F. Sarg, and F. M
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• Evaporite
  ...re minerals produced by the evaporation of water. This may occur in marine or nonmarine settings. The common evaporite minerals associated with petroleum
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• Regional pressure compartments
  ...tem overlying one or more hydraulic compartments whose pressures are above or below the normal static water pressure.<ref name=ch05r14>Powley, D., E., 19 ...surface (normally pressured hydraulic system). The '''top seal''' is more or less horizontal and usually cuts across stratigraphic units. It forms where
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• Siliceous microfossils
  ...recrystallized, preserved in nodules or concretions, or replaced by pyrite or calcite. ...e and nonmarine environments. Marine diatoms range from [[Upper Jurassic]] or [[Lower Cretaceous]] to [[Holocene]] and are particularly useful for age an
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• Tectonic inversion
  ...normal [[fault]]s are reactivated by [[compression]] (positive inversion), or where reverse faults are reactivated by [[extension]] (negative inversion).
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• Depositional trap regime
  ...thology. Where described, trap styles can be listed based on the lithology or composition of the sealing rocks. The outline below shows the classes and s ...servoir distribution. || colspan = 2 | ''Sandstone reservoirs''; Partially or completely isolated by seal.
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• Basement fault blocks and fault block patterns
  ...These zones of weakness are periodically reactivated by tectonic stresses or gravitational loading. Consequently, they have influenced depositional patt ...d terrains and demonstrate that the lineations fall into multiple parallel or subparallel sets of varying [[strike]] directions. These overlapping [[frac
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• Fishing
  * Bridging off by swelling formations or a collapsed hole. ...material, to sidetrack around the original material, to abandon the well, or to attempt to complete in a shallower zone. Because all but the first of th
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• Sandstone permeability estimation from cuttings
  | I || Rocks with pores capable of producing gas without natural or artificial fracturing. ...h pores capable of producing gas with natural or artificial fracturing and/or interbedded with type I rocks.
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• Waterflooding
  ...of oil and free gas by water. In waterflooding, water is injected into one or more injection wells while the oil is produced from surrounding producing w ...invasion or vertical sweep efficiency (''E''_V) and the pattern or areal sweep efficiency (''E''_P).
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• True resistivity determination
  ...contain formation water only ([[water saturation]] [S_w] = 100%) or [[formation water]] and hydrocarbons (S_w < 100%). Using a valid ...filtrate|resistivity (R_mf)]] is either greater than, less than, or equal to R_t and can distort deep resistivities. Distortions to r
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• Governance
  * Avoid complexity or obscurity
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• Postaccumulation cementation
  ...a petroleum phase may retard [[diagenesis]] in an [[accumulation]], sooner or later [[reservoir quality]] decreases with increasing age and burial.<ref n ...y]]). In low-permeability [[tight gas reservoirs: evaluation|tight sands]] or carbonates, the capillary [[displacement pressure]] in the reservoir rock m
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• Surficial geochemical interpretation guidelines
  ...one or more survey lines may indicate the location of discrete structural or stratigraphic targets within the survey area. If the basin or play is characterized by predominantly vertical migration, then the correla
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• Petroleum source rock formation
  ...hesis and nutrient supply. Under appropriate conditions, phytoplankton and/or algal/bacterial mats form in lacustrine, estuarine, and marine paleoenviron ...cted sediments at depths below wave base, in stagnant waters where density or temperature-stratified water columns form, and in other areas where oxygen
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• Limitations of oil correlations
  ...similar thermal maturities. Except in cases of extreme overmaturity of one or more of the samples, these problems can usually be overcome by an experienc ...or differences in technique between laboratories. The amount of acceptable or “normal” difference varies greatly, depending on the range of maturitie
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• Activation energy
  ...for chemical transformations, commonly expressed in kilocalories per mole or kilojoules per mole. Activation energy distributions are used in [[maturati
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• Early carbonate diagenesis
  Early [[diagenesis]] occurs at the surface or in the shallow subsurface. It is usually responsible for much of the cement ...ater flow combined with other factors result in precipitation of aragonite or magnesium (Mg) calcite.
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• Petroleum
  ...s composed mainly of hydrogen and carbon and found in the gaseous, liquid, or solid state in the Earth; includes hydrocarbon gases, bitumen, migrated oil
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• AAPG Wiki:Terms of use
  ...any changes to articles, and has full scientific authority over acceptance or rejection of alterations and deletions.
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• Using analogs to identify critical elements
  ...luck finding rabbits if he did not understand their habits—where they live or what and when they eat. In the same way, we learn about oil and gas fields ...trap to work. When we study local analog fields within a region or basin, or perhaps in a similar productive setting in another part of the world, we ca
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• Seismic data and mapping structure
  ...d|3-D data]]. The recipes described on the pages that follow apply to hand or computer work.
  2 KB (320 words) - 19:10, 27 January 2022
• Parasequences (fourth- and fifth-order sequences)
  ...000–200,000 years in duration) to be the building blocks of most reservoir or field studies. ...l]] extent and forms in response to (for example) [[tidal flat]] migration or [[Deltaic environments|delta]] lobe shifts. Episodic parasequences are of v
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• Natural gas occurrence
  ...ional gas accumulations as "continuous accumulations . . . that exist more or less independently of the water column," and discusses several methods for ...st have produced gas profitably in the United States for at least a decade or two and will undoubtedly become major sources of energy in the decades to c
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• Trap classification
  ...ap generally shares enough similarities with other traps in the same basin or in other basins that traps may be classified. The classification chosen dep ...onsequently, a classification scheme such as that used to organize a stamp or coin collection might be more useful, especially one in which a variety of
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• Measurement while drilling
  ...igure 1]]). Electrical energy for the system is provided by a battery pack or generated by a small turbine. ...rs are transmitted through the mud as positive or negative pressure pulses or as a continuous, fixed-frequency pressure wave.
  8 KB (1,083 words) - 21:18, 19 January 2022
• Seismic attributes in geological interpretation
  ...can take the form of dividing the attribute by either the actual isochron or by the number of time samples in the interval. Although this normalization ...the software vendor to provide well-written documentation, either on paper or online, that explains the mathematical calculation involved in generating t
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• Rig personnel
  ...e rig 24 hr a day, the crew(s) usually commute and work 8- or 12-hr shifts or tours. ...ed. A representive from the client company called the ''drilling foreman'' or ''company man'' is typically present on the rig. The company representive i
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• Sidewall coring
  ...ned in zones of interest using gamma logs or SP logs as guides. Percussion or rotary drilled samples provide small bits of formation material, suitable f ...data. Also, percussion sidewall core recovery tends to be low in very hard or fractured rock.
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• Petroleum system: geographic, stratigraphic, and temporal extent
  ...then the evidence that a petroleum system existed is absent. An incomplete or just completed petroleum system lacks a preservation time. ...stem. The stratigraphic extent is from below the pod of active source rock or the petroleum of the discovered accumulations in the system, whichever is d
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• Calcareous microfossils
  ...ure and high hydrostatic pressure, however, calcareous remains are largely or completely dissolved. The depth below which this occurs, which varies in di ...ular organisms (protists) that secrete a rigid calcite or aragonite shell (or test). Fossils of these forms are found in sediments of brackish to marine
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• Hydrocarbon expulsion, migration, and accumulation
  ...ding the pore pressure of the adjacent carrier bed. Oil or gas is expelled or “squeezed” into the carrier bed due to the differential pressures betwe ...density differential of the hydrocarbons and the formation water. The oil or gas migrates in filaments through the pore system of the aquifer as long as
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• Magnetotellurics
  ...tantly, can be used in places where seismic data collection is impractical or gives poor results. This is the same physical parameter that is measured in ...high-resistivity layers. It is difficult for MT to resolve more than three or four subsurface layers.
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• Migration pathway
  ...tervals. It leaves either no trace or a trace that is continually modified or destroyed by later events. Effective [[hydrocarbon migration]] occurs along ...this pathway, petroleum will accumulate until the trap is full and spills, or leaks, any additional migrating petroleum.
  6 KB (889 words) - 16:50, 29 March 2022
• Crude oil
  ...ndant compounds in crude oils, but they also contain nitrogen, sulfur, and/or oxygen (NSO) compounds and variable concentrations of trace elements, such
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• Unconformity
  ...record of geological time, during which deposition had ceased and folding or faulting occurred, the lower strata tilted, and then deposition resumed.]]
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• Carbonate porosity formation and preservation
  ...gins with good [[porosity]] and [[permeability]], either from depositional or early diagenetic processes, has a better chance of retaining those qualitie ...ric selective (fluid flow through interparticle or intercrystalline pores) or nonfabric selective (compaction).
  5 KB (708 words) - 17:27, 5 December 2023
• Mudlogging: drill cuttings analysis
  ...of lithology to wireline logs, and other special geological, geophysical, or engineering analyses (see [[Show evaluation]]). Some of the activities that ...an be obtained and used to evaluate prospective reservoir zones and casing or kick-off points.
  10 KB (1,482 words) - 15:25, 24 January 2022
• Rate of penetration
  ...n be expressed as either distance drilled per unit of time (feet per hour) or time per distance drilled (minutes per foot). ..., that is wrapped around a drum. The drum rotates one revolution in 8, 12, or 24 hr. To record depth, a small cable is run from the geolograph to the top
  7 KB (1,049 words) - 19:02, 20 January 2022
• Formation fluid pressure from drill stem tests
  A drill-stem test, or DST, is the most common method to measure reservoir pressure. DSTs are the * During '''run-in or run-out periods''', [[drilling fluid]] flows through ports in the tool wall
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• Sequences during low-amplitude, high-frequency cycles
  ...les of sea level (see [[Hierarchy of sequences]]) change because of little or no polar ice, and they tend to have high frequency and low amplitude. Read< * Cycles of 20 k.y. or less sometimes superimposed on 100- and 400-k.y. cycles
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• Fieldwork risk assessment
  As used here, ''risk'' is exposure to an undesirable outcome or chance at loss. In the case of exploration, it is exposure to the occurrenc The final step is to determine the information needed to reduce or further assess key risks. This step promotes free thinking and lets us visu
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• Macroseepage vs. microseepage in surficial geochemistry
  ...tion of faults, fractures, and outcropping [[Unconformity|unconformities]] or carrier beds. These visible seeps have led to the discovery of many of the ...ally detectable volatile or semivolatile hydrocarbons in soils, sediments, or waters. These invisible seeps are recognized only by the presence of anomal
  6 KB (754 words) - 22:07, 24 January 2022
• Predicting carbonate reservoir location and quality
  ...lity]] is defined as the “ability of a reservoir to store and transmit oil or gas.” We also can include the thickness and lateral extent as aspects of ...er#Sediment_supply_rate_and_facies_patterns|progradational, aggradational, or retrogradational patterns]] within sets. Make isopachs of systems tracts us
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• Correlation and regression analysis
  ...decrease as the other, y, increases or decreases, in a straight-line trend or relationship.<ref name=Draper_etal_1966>Draper, N. R., and H. Smith, 1966, ...tive for simple linear correlation when the number of samples is small and/or the joint distribution of the two variables is not simple. Multiple correla
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• Core handling
  ...is pulled. Every effort should be made to prevent the core from weathering or changing if s fluid contents. Speed is important when handling hard rock to ...d marking surface. Do not wash the core. Washing changes the fluid content or [[wettability]] and impacts the subsequent analysis.
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• Capillary pressure (Pc): buoyancy, height, and pore throat radius
  ...ta generated by these techniques cannot be compared directly to each other or to reservoir conditions. Below, we demonstrate how to convert pressures mea ...convert P_c to [[buoyancy pressure]], pore throat size (''r''), or [[hydrocarbon column]] height (''h''′). Assume water-wet conditions in th
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• Water saturation distribution in a reservoir
  BVW and Buckles plots can be confusing in interbedded lithologies or in areas where [[Lithofacies|facies]] changes occur because of changing por ...ng zone. Variations reflect different [[Reservoir quality|pore types]] and/or height above [[Free water level|free water]]. An S_w–depth plot
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• Seismic data display
  ...the type of anomaly you are trying to discern, such as porosity, gas zone, or facies changes. This allows the correct selection of a data processing flow ...reverse the display convention. Then the display is said to be ''reverse'' or ''negative polarity''.
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• Sequences during moderate-amplitude, high-frequency cycles
  Fourth- or fifth-order moderate sea level cycles (20–50 m) occurred when global clim * Abundant siliciclastics in bases and/or tops of sequences of land-attached platforms
  5 KB (674 words) - 21:22, 6 April 2022
• AAPG Wiki:Moderation
  *Too rigid or bureaucratic moderation can increase volunteer cost. ...specific subject matter expertise that would review articles independently or collaboratively and reach agreement to approve/flag articles
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• Carbonate facies
  ==Platform or ramp development==
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• Taphonomy and provenance
  ...difficult to recognize in [[Mudlogging: drill cuttings analysis|cuttings]] or even in cores and outcrops. ...anisms. A taphonomic study can help identify variations in ''provenance'', or source area, of fossil-bearing sediments.<ref name=ch17r55>Lawrence, D. R.,
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• Quartz
  ...many varieties—true quartz in the form of megaquartz, chert, microquartz, or chalcedony and various other forms of silica, mainly opal (opal-A and opal- ...dy and colored varieties occur where crystals are especially rich in water or mineral inclusions. In thin section, these colors are rarely seen, although
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• Fault seal behavior
  ...al behavior are (1) cross sealing or cross leaking and (2) [[dip]] sealing or dip leaking. '''Cross seal and leak''' refers to the ''[[lateral]]'' commun A fault does not simply seal or leak; many variations exist:
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• Pressure prediction: analysis of mud weights
  ...rt a pressure close to the expected pore pressure. When drilling mud kicks or [[Pressure_detection#Drilling_problems_with_overpressured_reservoirs|blows When the drilling mud kicks or blows out, pore pressure can be calculated by using the following formula:
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• Structural fairway prospectivity
  Certain [[structural domains]] or specific portions of those domains provide the greatest opportunities for e * Tectonic [[overburden]] or denudation
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• Oil and gas contracts
  ...angements. The most common types of contracts used are farm-outs-farm-ins, or well trade agreements, and joint operating agreements. ...ore than drill a well, including performing geological and seismic studies or paying a cash consideration for past costs incurred by the farmor.
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• How faults control trap fill and migration pathways
  ...g sealing faults. A [[fault]] can act as a barrier to (1) all hydrocarbons or (2) some of the hydrocarbons, allowing a limited volume to migrate. It can ...ly complex. Traps in this setting can have widely different migration/fill or [[Calculating charge volume|charge]] risks, depending upon [[fault seal beh
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• Microfossils in exploration
  ...ratigraphic]] or [[Paleoenvironmental analysis|paleoenvironmental]] range, or too poorly understood to be broadly useful in industrial application are no ...principal microfossil groups based on the composition of the shell (test) or hard parts. The table below shows the principal microfossil groups.
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• Toe
  The end point in a wellbore of the lateral section or sections is called the toe.
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• Seismic facies analysis
  ...ated with 90&deg; Ricker wavelets of 20-, 35-, and 80-Hz peak frequencies (or 26-, 45.5-, and 104-Hz predominant frequencies, respectively). No noise is ...cedure to analyze seismic facies from a grid of sections (vertical) of 2-D or 3-D [[seismic data]] (modified from <ref name=ch21r31 />).
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• Reducing exploration risk
  A play is one or more prospects that may define a profitable accumulation of undiscovered pe ...eum system case study is completed. As the case study develops, an idea(s) or play(s) that involves this petroleum system will occur to the investigator.
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• Main Page/News
  * [mailto:[email protected] Email matt], or call him on +1-902-980-0130
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• Diagenesis: information from petrology
  | Oil-filled fluid inclusions in reservoir or carrier beds || Indicates migration pathways and absolute timing of migrati ...ng of [[leakage]] || [[Hydrocarbon column|Column]] height may be small and/or [[Dip|updip]] (spilled) accumulations may exist
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• Oil correlation case histories
  ...ut and not from secondary processes such as [[maturation]], [[migration]], or [[biodegradation]].
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• Carbonate diagenetic stages
  ...structures of skeletal grains or within nonskeletal grains such as pellets or ooids. ...al deposition. All the porosity that forms during this stage is diagenetic or secondary in origin. Diagenetic processes are related to changes in water c
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• Geothermal gradient
  ...erature with depth in the Earth, commonly in degrees Celsius per kilometer or degrees Fahrenheit per 100 feet. Gradients are sensitive to basal heat flow
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• Hydrocarbon pressure gradient: plotting
  # Determine a pressure above or below the measured depth point. The table below lists the steps for determi ## Pick a depth above or below the measured point.
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• Oil correlation
  Correlations are comparisons of two or more samples based on the physical and chemical properties of those samples ...termine whether a genetic relationship exists among a group of oil samples or between an oil and a proposed [[source rock]]. Positive correlations are al
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• Seismic data preparation for mapping
  # Compute a synthetic seismogram for each online well with a sonic or [[density log]]. ...l_seismic_profiles|vertical seismic profile (VSP)]], synthetic seismogram, or time-stretched logs.
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• Predicting reservoir drive mechanism
  * High recovery factor (50% or more) * Water-free production (or relatively minor)
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• Workovers
  A ''workover'' is any operation done on, within, or through the wellbore after the initial completion. Although proper drilling ...uction casing, even smaller equipment is run for completion and production or injection purposes. [[:file:workovers_fig2.png|Figure 2]] illustrates the t
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• Molecular fossils
  ...ocks, sediments, fossils, or oils that can be reliably associated with one or a few biotic antecedents. The term “molecular fossil” is limited here t ...or in oil provides information about the paleoenvironment of the sediment or source.
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• Sandstone provenance and characterization
  ...them and to make them deposited. That’s why we can found the sand deposit or sandstone almost in everywhere. ...s are minerals that are not formed on the environment during sedimentation or sedimentation occurs. These minerals come from rocks that have undergone tr
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• Influence of depositional environment on sandstone diagenesis
  ...ble. The energy level of depositional environments affects sorting by size or hydraulic equivalence and consequently produces different detrital mineral ...ays that are products of disaggregation. Reworked sands, such as shoreline or tidal sands, are more quartzose.
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• Sea level cycles and carbonate diagenesis
  ...er diagenesis does not occur or is greatly reduced because there is little or no pore-water movement. High-frequency sea level cycles (fourth or fifth order) cause the cyclical migration of the vadose, freshwater phreati
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• Production histories
  ...nduct a project, well testing and simulation can be used to supplement and/or upgrade the quality of forecasts generated by production histories (see [[P ...it does not anticipate changes in performance due to operating conditions or changes in reservoir behavior (for more on decline curves, see [[Reserves e
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• Picking horizons in 3-D data
  ...however, assumes that a horizon is locally very smooth and perhaps linear (or planar in two dimensions) between control points. If this assumption is vio ...utopicking is quite simple. The interpreter places seed picks on lines and/or cross-lines in the 3-D survey. These seed points are then used as initial c
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• Well planning
  * Straight, slanted, or [[Well types#Horizontal well|horizontal well]] ** Hot wire or flame ionization detection (FID) chromatograph
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• Petrophysical analysis of lithofacies
  ...strongly influenced by its environment of deposition. Diagenesis can alter or completely change the original pore space of a rock, especially for carbona ...ty]] data. Categorize each flow unit by port type as mega-, macro-, meso-, or microporous.
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• Geological fieldwork benefits
  ...vance specific business recommendations on how to proceed with exploration or manage technical risk. ...e an explorationist has in his or her work. In presentations to management or investors, that “been-there” confidence shows through.
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• Measuring displacement pressure using mercury injection
  ...orcing mercury into the pore space of a sample ([[Core description|cores]] or [[Mudlogging: drill cuttings analysis|cuttings]]) and measuring the percent ...nced plateau along which saturation rapidly increases. The pressure at 10% or 40% saturation gives a similar P_d.
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• Top seal displacement pressure
  * θ = contact angle or [[wettability]], degrees ...PG Bulletin, vol. 59, no. 6, p. 939–956.</ref> If the wetting phase is oil or gas rather than water, the contact angle can range from 0 to 180°. Not all
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• Hydrology and sandstone diagenesis
  ...g water moves chemical components through pores and causes either leaching or cementation of grains. Diffusion also moves chemicals in and out of rocks, ...waters. Deeper infiltration occurs from (a) eustatic sea level changes and/or (b) tectonic elevation of basin margins.
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• Cross-sealing fault
  ...oss sealing if it juxtaposes sands with different hydrocarbon contacts and/or different free water levels. ...oss sealing if it juxtaposes sands with different hydrocarbon contacts and/or different free water levels, as illustrated in [[:file:evaluating-top-and-f
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• Oil shale
  ...ry petroleum solvents, from which substantial amounts of synthetic oil and/or gas can be extracted by heating it to a sufficiently high temperature, a pr ...the development of new mining and processing technology for the oil shale or a substantial increase of the price of oil may make oil shales with lower o
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• Sequence stratigraphy analysis
  ...ted and can be preserved. Organic-rich rocks are colored dark gray, black, or chocolate brown, reflecting their relatively high volumetric ratio of organ ...hic sequences. Most woody coals generate gas, although some bear the algal or bacterial components that can generate oil. Gas-prone terrestrial organic m
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• Seismic interpretation
  ...a, proper interpretation still requires that the interpreter draw upon his or her geological understanding to pick the most likely interpretation from th ...interpreter to study. The first is the time of arrival of any reflection (or refraction) from a geological surface. The actual depth to this surface is
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• Elemental parameter data for oil–oil and oil–source rock correlations
  ...e below. Therefore, unless the maturity levels of all samples are similar, or unless some correction for maturity is made, sulfur content can be misleadi ...cs), lighter nonhydrocarbons (NSOs [nitrogen, sulfur, oxygen], [[polar]]s, or [[resin]]s), and heavier nonhydrocarbons ([[asphaltenes]]). Oils with terre
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• Magnetics: petroleum exploration applications
  ...can occur along [[basement]] block boundaries and (2) subtle fault offsets or other structural and stratigraphic features. The locations of the basement ...m well data. However, on overseas projects or in frontier areas, the best (or only) data available may be 2-D seismic surveying. In either case, the proc
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• Density-neutron log porosity
  ...mates of porosity are possible with the combination than using either tool or sonic separately because inferences about lithology and fluid content can b ...t bulk density to porosity using charts in a log interpretation chartbook, or calculate porosity from bulk density using this equation:
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• Mudlogging: gas extraction and monitoring
  ...tection of a gas influx will give rig crews time to respond to toxic gases or a potential blowout condition. Accurate gas data recorded during drilling i ...This aids in identifying the types of hydrocarbons in place (that is, oil or gas).
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• Wellsite safety
  ...ry or death. The wellsite is a hostile environment, often either very cold or very hot, wet, and slippery. Hazards include heavy equipment being moved ar ...his practice may include having personnel donning life jackets, air packs, or survival suits and assembling at the escape boat. Some drills include board
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• Factors that cause migration
  ...me time during the migration process. Each factor produces energy from one or more sources. The table below lists these factors and their corresponding e | Presence of oil or gas
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• Depositional sequence identification
  A depositional sequence is bounded by [[Unconformity|unconformities]] or the correlative conformity. It is subdivided by internal surfaces of [[tran ...[[Biostratigraphic correlation and age determination#Changes in abundance or composition|abundance patterns]] that may suggest depositional sequences.
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• Strain analysis of top seals
  ...nt seep]] in the Santa Barbara Channel, California, is leaking 50–70 bbl/d or more than 25 billion bbl/m.y.<ref name=ch10r95>Wilkinson, E., R., 1971, Cal
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• Reflection configuration patterns
  ...ain. Divergent reflectors suggest lateral variations in depositional rates or progressive tilting of a depositional surface. [[:file:exploring-for-strati ...coarse-grained [http://www.merriam-webster.com/dictionary/fluvial fluvial] or [[turbidite]] channel fills. Contorted features may be shale-prone [[debris
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• Kickoff point
  The kickoff point (KOP) is the location in a vertical wellbore or inclined section of a slant well where directional drilling operations comm
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• Petroleum system
  ...from one pod of active [[source rock]] and occurs in [[show]]s, [[seep]]s, or [[accumulation]]s;<ref name=Magoonanddow_1994>Magoon, L. B., and W. G. Dow, ...nd processes are known to occur or are thought to have a reasonable chance or probability to occur.
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• Seismic data acquisition on land
  ...ly provide adequate accuracy, given sufficient control. However, in remote or previously unsurveyed areas, satellite stations may be necessary to provide ...acord) ([[:file:seismic-data-acquisition-on-land_fig1.png|Figure 1]]), gas or air guns, weight drop mechanisms, vibrator systems ([[:file:seismic-data-ac
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• Interpreting gravity measurements
  ...ns as geologically unreasonable, it is best to start with good constraints or to test reasonable geologic questions. Gravity is not as good at depth-to-basement or depth-to-density anomaly estimations as other [[geophysical methods]]. Thou
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• Migration rate
  ==Hydrodynamics or compaction transport rate== ...rate. In practice, however, the additional force supplied by hydrodynamics or compaction is largely counterbalanced by capillary forces and relative [[pe
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• Surface geochemical exploration: assumptions
  ...m/data/bulletns/1982-83/data/pg/0067/0006/0900/0932.htm Predictions of oil or gas potential by near-surface geochemistry]: AAPG Bulletin, vol. 67, p. 932 ...ncreasingly difficult as the geology becomes more complex. The geochemical or microbial anomaly at the surface represents the end of a petroleum [[migrat
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• Sampling for paleontology
  ...nt of drill pipe added to the drill string (i.e., every [[length::30 ft]], or 9 m) and represents an amalgamated sample of the rocks penetrated in that i Although the use of cuttings is less precise than conventional or sidewall cores, this method of sampling can yield surprisingly robust paleo
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• Dip
  ...dicular to strike; this requires that a strike be given), 4 SE (likewise), or 4 65SE (dipping 4 degrees in a 65SE direction; this by inference gives the
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• Paleoclimatology
  ...hy]] provides the only practical means to demonstrate the contemporaneity, or lack of it, of contrasting climates. ...distinctive climates or environments may have distinctive characteristics, or '''morphologies'''. Recognizing these features in fossils can provide infor
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• Sea level cycles and climate
  ...ly in different regions during icehouse or greenhouse periods. The aridity or humidity of a region strongly affects carbonate deposition and [[diagenesis ...ater carbonate settings where the photic zone extends to [[length::100 m]] or deeper. Tropical carbonate faunal assemblages strongly depend on light, whi
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• Lateral
  Lateral is a term applied to either a single branch or individual multiple ([[multilateral well|multilateral]]) branches off the v
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• Sea level cycles and carbonate sequences
  ==Parasequence sets or systems tracts== ...#Sediment_supply_rate_and_facies_patterns|retrogradational, aggradational, or progradational patterns]]. A parasequence set approximately corresponds to
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• Pyrolysis gas chromatography
  ...ted on whole rock or isolated kerogen samples to obtain a visual signature or “fingerprint” of the organic material present. ...her with the products of natural [[Petroleum generation|generation]] (oil) or with the products of laboratory pyrolysis of the [[asphaltenes]] from oils.
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• Pressure prediction: analysis of cuttings
  ...to subsurface pressure conditions as reflected in the state of compaction or induration of the rock. This applies to cuttings from permeable as well as ...he cuttings will be further broken (smaller than normal) and may look worn or abraded. This process is more likely to take place in permeable zones where
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• Sandstone diagenetic processes
  ! Preserves or enhances porosity || Destroys porosity | Shallow || <80&deg;C or 176&deg;F (<5,00 to 10,00 ft)
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• Geologic mapping (UB)
  ...ological bearings ([[strike]] and [[dip]]s), faults, folds, [[fracture]]s, or many processes have had occurred in earlier times. The Soil might either be coloured, by variety of Lines, or Etchings; but the great care must be, very exactly to note upon the Map
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• Classification basis
  ...in purpose of the proposed scheme is to help explorationists find more oil or gas traps. A well-constructed classification scheme for traps can serve oth ...that animals are mobile and can search for food, whereas plants are fixed or rooted and rely on food to be brought to them.<ref name=ch02r2 />
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• Techniques for enhancing seismic facies analysis
  ...epth and coverts it to time. Put another way, forward modeling takes a 2-D or 3-D geological model and converts it to a simulated seismic section. The si * Interpret stratigraphy and fluid composition at or near the limits of seismic resolution by waveform analysis.
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• Fluidic trap system
  ..._gas.aspx gas] accumulations in which the trapping element is the physical or chemical condition of the [[reservoir fluids]]. There are three regimes in
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• Top seal integrity: Central Graben example
  ...ng-top-and-fault-seal_fig10-39.png|Figure 1]] is an example of evaluating, or risking, top seal integrity using two traps in the Central Graben, North Se ...top-and-fault-seal_fig10-39.png|300px|thumb|{{figure number|1}}Evaluating, or risking, top seal integrity using two traps in the Central Graben, North Se
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• Shale gouge ratio
  The shale gouge ratio is simply the percentage of [[shale]] or [[clay]] in the slipped interval. [[:File:Shale-gouge-ratio-fig3.png|Figure ...y material). The SGR represents, in a general way, the proportion of shale or clay that might be entrained in the fault zone by a variety of mechanisms.
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• Rock quality
  ...is much more effective for determining quality. The K_a/Φ ratio or the r₃₅ method yields information about the fluid flow and stora ...f fluid flow efficiency and storage, as shown by the K_a/Φ ratio or r₃₅, flow unit 2 is actually the better rock.
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• Surficial geochemical survey objectives
  ..., distribution, and composition of hydrocarbons in the area of exploration or development interest and ...m/data/bulletns/1982-83/data/pg/0067/0006/0900/0932.htm Predictions of oil or gas potential by near-surface geochemistry]: AAPG Bulletin, vol. 67, p. 932
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• Mudlogging: equipment, services, and personnel
  ''Mudlogging'', sometimes called hydrocarbon logging or physical formation logging, involves the monitoring and recording of a vari ...pressure and flow alarm and purge system to detect vacuum system blockage or leaks.
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• Cased hole tools
  ...y or safely making the necessary open measurements or because insufficient or inappropriate open hole measurements were taken over particular zones. ...e life of a well, changes in saturation of the pore space by oil, gas, and/or water may be induced by sustained production. When these changes occur, eva
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• Burial history chart
  ...ming of petroleum generation based on calculated [[vitrinite reflectance]] or other maturity parameters are commonly overlain on the burial history diagr
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• Pressure compartment seals
  A seal can be either a pressure seal, a capillary seal, or both. They are defined as follows: ...where [[capillary pressure]] across the pore throats of a rock is greater or equal to the buoyancy pressure from a [[hydrocarbon column]]. Water can mov
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• Diagenetic traps: criteria for recognition
  ...http://www.minersoc.org/pages/Archive-MM/Volume_53/53-373-547.pdf saddle]] or nonplanar dolomite, ferroan [http://encyclopedia2.thefreedictionary.com/poi ...boundaries within a given formation not coincident with structural closure or facies boundaries
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• Definitions of depositional system elements
  A depositional sequence is bounded by [[Unconformity|unconformities]] or the correlative conformities and is subdivided by internal surfaces of tran ...ring one phase of relative sea level cycle, such as lowstand systems tract or highstand systems tract.
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• Stratigraphic trap system
  ...stratigraphic in nature and formed as a result of depositional, erosional, or diagenetic processes. These processes are the basis for the three regimes o
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• Production problems
  ...oblems can be avoided or delayed through preventive maintenance techniques or early recognition from regular analysis of producing rates, fluids, and the ...om/en/Terms.aspx?LookIn=term%20name&filter=oil-water%20contact oil-water] (or oil-gas) contact. When the vertical pressure gradient exceeds the hydrostat
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• Drive mechanisms and recovery
  ...present in the same reservoir. A combination drive may also occur when one or more of the primary drive mechanisms are assisted by ''gravity drainage''. In a solution (or dissolved) gas drive reservoir, the oil-bearing rock is completely surround
  16 KB (2,374 words) - 20:46, 19 January 2022
• Growth fault
  ...lishment Pluton) or core metamorphosis process. Beginning a rigid material or ductile experiencing high angle normal faults when the basin is formed (pre Normal fault zone formed on a fairly broad traction as the plume dimantel or at the time of the formation of the basin. This tug zone causes normal faul
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• Biostratigraphic correlation and age determination
  ...owest occurrence of a species or lineage, is a reliable datum only in core or [http://www.merriam-webster.com/dictionary/outcrop outcrop] samples because ...1–875.</ref> The clustering of fossil extinctions often represents missing or condensed sections. Correlation of tops is the most rapid and economical bi
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• AAPG Wiki:Editing the main page
  ...e image at least 400 &times; 400 pixels — you can use Apple Preview, GIMP, or any image editing software.
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• Stratigraphically complex fields
  |   Fluvial or deltaic [[sandstone]] on carbonate shelf |   Shelf edge, slope or basinal
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• How to plot the strike data to the Rosette diagram
  ...other planar feature and a horizontal plane. Strike indicates the attitude or position of linear structural features such as faults, beds, joints, and [[ ...st the outcrop and then the compass against the book to get a smoother and/or a larger surface), until the air bubble in the "Bull's eye level" is center
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• Seal thickness
  ...ractured]] completely, or of having local variations in fracture intensity or [[Pore and pore throat sizes|pore throat diameter]] that provide a leakage
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• Risk: dealing with risk aversion
  ...get), the magnitude of potential gain (or loss), and the chance of success or failure. Risk aversion makes small and large firms respond differently to t ...iarity || The “comfort bias”: decision makers are more risk prone in deals or environments with which they have had past good experience
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• Offshore rigs
  An offshore rig is a large structure on or in water with facilities to drill wells, to extract and process oil and [ht ...led ''floaters''. These rigs can drill in water depths deeper than jackups or platforms can. They have several special features to facilitate this:
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• Pressure prediction: analysis of well-log and seismic data
  ...sity logs (as well as some others) can give clues to the presence of over- or underpressure. Shale sections are best for analysis of logs for abnormal po ...asonably thick to allow valid responses of the other logs and free of sand or lime stringers. (See points a–e, [[:file:formation-fluid-pressure-and-its
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• Type I kerogen
  ...ee common source rock evaluation errors made by geologists during prospect or play appraisals]: AAPG Bulletin, vol. 93, issue 3, pp. 341-356.</ref>]]
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• Solar energy
  ...t, most dependable technology to harness the power of the sun. Solar cells or solar modules are easy to install and, as a result of their simplicity, req ...ns, remotely located communities and dwellings, space vehicles, and marine or air navigation beacons.
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• Tar sands
  ...define tar sands as "reservoirs that contain low-gravity oil (~10&deg; API or less) and need a large thermal input to reduce the oil viscosity to a level ...or extra-heavy-oil accumulations having remained undiscovered, unreported, or undeveloped. All important tar-sand deposits may therefore not have been di
  7 KB (1,012 words) - 13:40, 18 March 2019
• Coal
  ...l fuel] source of energy; coal reserves are 5 times as large as either oil or gas reserves, and coal resources are estimated to be about 17 times the oil ...lassified by rank, which essentially indicates the degree of coalification or stage of metamorphism that a coal reaches in its slow, progressive transfor
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• Mudlogging: the mudlog
  ...). Each mudlogger is responsible for plotting the data acquired during his or her tour. In this way, the mudlog becomes an accurate and up-to-date record ...d to prevent confusion or misunderstanding over the meaning of a log trace or annotation.
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• Types of completions
  ...ngle perforated casing completions are used; however, multiple, alternate, or slim hole completions may be used under certain conditions. The choice of c ...be set prior to drilling and logging the reservoir. If for some geological or engineering reason the target formation is not productive, then money has b
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• Paleobathymetry
  ...ocene, Pliocene, and Miocene foraminiferal species either are still living or have very close living relatives in modern oceans. In practice, this evolut ...meter because it does not directly influence the morphology, distribution, or biological processes of marine organisms. However, foraminifera can help us
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• Dolomite
  ...ty exists for reactions to occur toward a more stable (more stoichiometric or better ordered) phase. ...olomite that is stable in a given environment, or are imperfectly ordered, or both, but which would transform to dolomite if equilibrium were established
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• Oil and condensate analysis
  ...These data also can be essential for equity studies and for environmental or pollution cases. Table 1 provides a quick reference to common questions tha | Drilling additive or contaminant or formation fluid
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• Monte Carlo and stochastic simulation methods
  ...oil saturation (S₀), and a binary indicator (I) set equal to 1 or 0 depending on whether the sample location belongs to a certain pay formati ...t, it is essential to evaluate the uncertainty attached to these estimates or, better still, to evaluate the probability distributions of the response va
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• Water resistivity determination
  ...shales). Deflections to the left of the shale line are regarded as normal or negative, and correspond to porous and permeable zones containing a more sa ...he right of the shale line. Such a deflection is considered to be reversed or positive ([[:file:determination-of-water-resistivity_fig2.png|Figure 2]]).
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• Kinetics
  ...ub>46</sub>-C₅₅, C₅₆-C₈₀), compound type, or a combination thereof.<ref name=Petersetal_2012>Peters, Kenneth E., David J
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• Gravity in petroleum exploration
  ...ravity meter has broad application, from locating [[porosity]] in wildcats or through [[casing]] in old wells to monitoring fluid changes in productive [
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• Land rigs
  ...ferent rig systems by belts, chains, and drive shafts on a mechanical rig, or by generated DC electrical power on an electric rig. Power is distributed t ...end of the drill collars is the ''bit''. The bit does the actual grinding or cutting of the rock. The style of bit used is dependent on the rock type an
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• Type II kerogen
  ...ee common source rock evaluation errors made by geologists during prospect or play appraisals]: AAPG Bulletin, vol. 93, issue 3, pp. 341-356.</ref>]]
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• Vertical and lateral seismic resolution and attenuation
  ...apart two interfaces must be to distinguish separate reflections from them or how thick a bed must be to allow distinguishable reflections from the bed's ...velocity of about 6000 ft/sec for a wavelet with 60-Hz dominant frequency, or about [[length::250 ft]] for a deep bed with 15,000 ft/sec velocity and a 1
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• Type III kerogen
  ...ee common source rock evaluation errors made by geologists during prospect or play appraisals]: AAPG Bulletin, vol. 93, issue 3, pp. 341-356.</ref>]]
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• Botucatu Formation
  ...sorted, texturally mature, may contain altered feldspar cemented by silica or iron oxide, which gives it the reddish color and also shows inverse grading
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• Sandstone
  ...mmon in the geologic record one-third of all sandstones and commonly white or light, may be stained red, pink, yellow and brown by iron oxides. ...abundant presence of potassium feldspars or iron oxides, may be light gray or white. Its contain less than 90 percent [[quartz]], more feldspars than lit
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• Pressure compartments
  ...depths of [[depth::2500 m]] and 25% or more at depths of [[depth::3000 m]] or more.<ref name=ch05r12 /> These porosities are those that would be expected
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• Who finds oil?
  Theoretically, every geologist with a master's degree or higher from an accredited institution has the necessary scientific backgrou ...a problem can be a successful approach. However, the creative spark of one or more members of the team to correctly interpret the geology (with the aid o
  6 KB (826 words) - 14:29, 18 February 2022
• Preprocessing of logging data
  The preprocessing or data preparation step is potentially the most time-consuming part of a larg ;1. Move digital log data from logging field tapes or digitized logs to the log processing environment: If paper copies of logs w
  13 KB (2,094 words) - 17:42, 18 January 2022
• Geology
  ...e little evidence of the original form and character of the rock. Physical or ''dynamic geology'' is the name commonly applied to the field of specializa
  4 KB (561 words) - 21:20, 1 February 2023
• Stratigraphic trap
  ...ositional trap regime|depositional]], [[Erosional trap regime|erosional]], or [[Diagenetic trap regime|diagenetic]] processes. As technology evolves and
  1 KB (176 words) - 12:51, 3 July 2014
• Reservoir system analysis
  ...the field. Reservoir performance affects the economic viability of a play or prospect and is a function of reservoir system quality. Performance is expr ...ir system quality is the capacity of a reservoir to store and transmit oil or gas. The quality of a reservoir system is determined by its
  4 KB (547 words) - 18:09, 1 April 2022
• Nature of the oil and gas lease
  ...as are to be included in the property described, to a lessee, for a fixed or determinable period of time. In some cases, ''top'' leases are obtained on ...s, may agree to perform certain services, such as drilling and seismic and/or geological surveys. Also, the lessee provides the lessor with a cost-free r
  15 KB (2,397 words) - 19:26, 19 January 2022
• Pc curves and saturation profiles
  ...y pressure, i.e., [[hydrocarbon column]]. Macropore reservoirs have little or no saturation transition zone. ...ropore reservoirs have longer saturation transition zones than macroporous or [[Wikipedia:Mesoporous material|mesoporous]] reservoirs; immobile water sat
  5 KB (752 words) - 16:53, 4 April 2022
• Conventional coring
  ...thout the expense of [[trip]]ping pipe. A mature field might need a sponge or pressure core to help pin down remaining reserves. These three situations d ...nsure success when coring unconsolidated sand, also incorporate split ring or slip type catchers to improve core recovery in the event that coring ends i
  13 KB (1,885 words) - 20:49, 19 January 2022
• Magnetotellurics survey measurements
  The H-field is the “source” signal, or the primary field. It propagates across the surface of the earth. Because i ...is the same physical principle as the alternator in a car. An alternating or spinning magnetic field (H-field) sets up current flow in the wire windings
  4 KB (519 words) - 19:57, 27 January 2022
• Surface production equipment
  ...l equipment on the lease. After the oil and gas leaves the lease, pipeline or facilities engineers take over. ...g head, and a Christmas tree. For each string of pipe in the well, casing, or tubing, some means of support and pressure sealing must be provided. This i
  9 KB (1,343 words) - 18:42, 20 January 2022
• Production logging
  ...y larger in diameter. These surveys are run before the tubing is in place, or else it must be removed and the well shut-in. * Evaluating the effectiveness of well treatment or [[workover]] operations by comparing the before and after job surveys
  12 KB (1,726 words) - 16:48, 20 January 2022
• Midale porosity, pore geometries, and petrophysics
  ...than 1μ in radius, with an abundance of pore throats about 0.5μ in radius or smaller (see [[:file:predicting-reservoir-system-quality-and-performance_fi
  5 KB (659 words) - 16:54, 12 April 2022
• Micropermeable seal leakage
  ...no longer zero, but it may be small. Finally, where [[fracture]]s are few or where fracture apertures are very small, fracture porosity may be invaded, ...more likely to suffer micropermeable leakage than accumulations under salt or claystone seals.<ref name=ch11r11>Grunau, H., 1987, A worldwide look at the
  5 KB (742 words) - 17:11, 1 February 2022
• Enhanced oil recovery
  ...njection of chemical compounds dissolved in water, the injection of steam, or the injection of a gas that is miscible with the oil in place. As a result, ...recovery operations. The main factors that control the value of ''S''_or are pore geometry, rock [[wettability]], and the properties of the di
  12 KB (1,794 words) - 21:19, 19 January 2022
• Wireline formation testers
  # gas-oil or water-oil contacts, and ...ssure measurement, the formation tester is activated and hydraulically set or pressed against the formation. These conditions are shown schematically in
  10 KB (1,446 words) - 17:42, 18 January 2022
• AAPG statement on hydraulic fracturing
  ...ids vary widely, the commonly used ingredients are limited in toxicity and/or mobility in water.
  1 KB (187 words) - 16:47, 18 July 2016
• Log interpretation: initial quick scan
  ...r]] than nonreservoir information, and when one is unfamiliar with an area or wants to broadly reconnoiter an area, a scanning technique that sorts reser ...be radioactive productive zones. ²Shaly zones might produce oil or gas even if they have low resistivity.<ref name=AsquithandKrygowski_2006>As
  4 KB (543 words) - 14:11, 21 August 2014
• Natural gas: history and forecast
  ...en rid of as cheaply as possible, commonly by venting it to the atmosphere or by [[flaring]] it. Exploratory drilling for natural gas was not seriously c ...and distributing it. Natural gas can only be transported through pipelines or in liquefied form in special, very expensive cryogenic tankers. There was l
  5 KB (786 words) - 16:33, 25 June 2015
• Rock Eval analysis using hydrogen index (HI) and oxygen index (OI)
  ...e II kerogen|II]], or [[Type III kerogen|III]] and if the rock will be oil or gas prone.
  3 KB (525 words) - 18:09, 9 February 2022
• Production testing
  ...d buildup tests) are impractical due to time constraints, well conditions, or extremely low well productivity. ...ressure buildup tests from which [[permeability]] and the extent of damage or stimulation can be estimated.<ref name=pt09r14>Lee, W. J., 1982, Well Testi
  14 KB (2,165 words) - 18:42, 20 January 2022
• Sandstone diagenesis: composition and texture
  ...he variety of minerals, the lower the chemical stability (more cementation or dissolution occurs). Sandstones with abundant lithics, feldspars, or [[chert]] have less occlusion of [[porosity]] by quartz overgrowths and mor
  5 KB (729 words) - 20:48, 5 April 2022
• Thermal maturation
  ...ic matter (e.g., conversion of sedimentary organic matter to [[petroleum]] or [[cracking]] of oil to [[gas]].) Different geochemical scales, such as [[vi | Vitrinite reflectance (V_r or R_o )
  8 KB (1,113 words) - 18:10, 24 January 2022
• Flow units and containers
  ...type. Petrophysical characteristics, such as distinctive log character and/or porosity-[[permeability]] relationships, define individual flow units. Infl ...reservoir system subdivision'' consisting of a pore system, made up of one or more flow units, that responds as a unit when fluid is withdrawn. Container
  9 KB (1,231 words) - 18:42, 1 April 2022
• AAPG Wiki:Wikification
  ...hink of it as all the things you need to do to the Encyclopedia Britannica or a mid-term essay into a Wikipedia article. The main element is formatting u * Formatting all lists as wiki lists, ordered or unordered
  8 KB (1,043 words) - 14:09, 6 August 2013
• Mancos Shale Play in New Mexico
  ...nvariably from the Upper Mancos, from an interval sometimes called El Vado or Niobrara. Unfortunately, some pools that produce from the same stratigraphi ...wer units (e.g., the Dakota; [[:file:Figure2MancosCommRept.jpg|Figure 2]]) or higher units (e.g., Mesaverde, Pictured Cliffs, Fruitland; [[:file:Figure1M
  6 KB (985 words) - 20:14, 2 June 2021
• Hydrodynamic flow and pressure transients
  A hydrodynamic gradient will either increase or decrease the height of a trapped [[hydrocarbon]] column.<ref name=ch10r67>S ...capacity based upon the capillary model assume a static pressure gradient or a uniform regional hydrodynamic gradient.
  4 KB (477 words) - 14:34, 1 April 2022
• Other correlation features
  ...or nondeposition, but not by subaerial erosion due to stream rejuvenation or basinward shift in facies”.<ref name=ch21r45>Van Wagoner, J. C., 1995, [h ...he condensed section. In starved areas, it is associated with a hardground or marine dissolution surface.<ref name=ch21r48>Weber, L. J., J. F. Sarg, and
  6 KB (872 words) - 15:20, 4 February 2022
• Van Krevelen diagram
  ...ee common source rock evaluation errors made by geologists during prospect or play appraisals]: AAPG Bulletin, vol. 93, issue 3, pp. 341-356.</ref>]]
  1 KB (194 words) - 15:46, 8 March 2016
• Seismic interpretation: surface slicing
  ...atio]] than [[Picking_horizons_in_3-D_data#Voxel_tracking|voxel tracking]] or [[Picking_horizons_in_3-D_data#Autopicking|autotracking]] because it is not * [[Two- or three-dimensional interpretation]]
  4 KB (553 words) - 19:30, 27 January 2022
• Burial destruction
  ...t of an [[accumulation]], the conversion of [[oil]] to [[Natural gas|gas]] or dilution of gas by nonhydrocarbon components in the deep burial environment ...ld not be expected at subsurface temperatures > [[temperature::150&deg;C]] or a [[maturation]] level much above 1.3% R_o. Dry gas accumulations
  11 KB (1,525 words) - 18:50, 1 February 2022
• Seal ductility
  | Composition || Not all limestones or shales have the same ductility. Compositional variations such as total orga | Fluid composition || The presence or absence of fluids and their composition affects ductility.
  4 KB (510 words) - 15:22, 30 March 2022
• Electrical methods
  ...of the subsurface can be interpreted in terms of soil characteristics and/or rock type and geological structure. Resistivity data are usually integrated ...an-generated) energy source and those using naturally occurring electrical or electromagnetic energy as a source. The controlled source methods are most
  15 KB (2,130 words) - 21:19, 19 January 2022
• Mapping unconformities
  ...surface to predict trap location. Traps can be located above (onlap traps) or below (truncation traps) the unconformity. Seals, reservoir-quality rocks, ...to a flat datum above or below the unconformity to define paleotopography or paleostructure (see [[:file:exploring-for-stratigraphic-traps_fig21-35.png|
  7 KB (977 words) - 20:39, 4 February 2022
• Seismic data: analyzing individual reflectors
  ...lysis within specific reflectors can give us clues to changes in lithology or [[porosity]].
  4 KB (481 words) - 18:20, 4 February 2022
• Core orientation
  ...r orientation of a core cylinder is determined. Typically, a mark, groove, or line is placed on the surface of the core and the ''in situ'' [[azimuth]] o ...can be discerned in the core, it may be possible to use [[dipmeter]] logs or data from [[Borehole imaging devices|borehole televiewers]] to determine th
  13 KB (1,964 words) - 20:50, 19 January 2022
• Depositional sequence analysis of plays
  ...stratigraphy of a basin. This is especially true in basins containing oil or gas traps that can be used as analogs. [[Sequence stratigraphy]], interpret ...raphic changes, such as updip pinch-outs of rocks with reservoir potential or mounds of reservoir-quality rocks, in the context of a depositional sequenc
  8 KB (1,184 words) - 20:44, 4 February 2022
• Relationships between maturity and hydrocarbon generation
  ...(R_o) are generally associated with the onset of oil generation or indicate the top of the oil window. However, this generality applies only i
  2 KB (220 words) - 16:10, 10 February 2022
• Charge volume
  ^{* A function of lithology, depth, degree of fracturing, and/or faulting} ...ydrocarbons should be migrating. A rougher estimate can be made from a map or the stucture as it exists today. A drainage map is made from the migration
  6 KB (834 words) - 20:41, 14 February 2022
• 3-D seismic data: the data cube
  ...-D seismic lines? A 3-D seismic survey has many advantages over a 2-D line or a grid of 2-D lines—even a dense one. (A 2-D grid is considered dense if ...from a [http://wiki.seg.org/wiki/Crossline_smearing cross-line smearing], or [http://wiki.seg.org/wiki/Dictionary:Fresnel_zone Fresnel zone], problem)
  5 KB (813 words) - 19:05, 27 January 2022
• Seismic data interpretation - recurring themes
  ...s, in effect, an edge detection technique. The bigger the [[velocity]] and/or [[density]] contrast between the rocks, the stronger the edge. ...]]s, including a [[Fluid contacts|fluid contact]], [[porosity]] variation, or shale density change.
  5 KB (739 words) - 18:51, 27 January 2022
• Overview of routine core analysis
  ...ore analysis can be divided into several different types: (1) conventional or plug analysis, (2) whole core analysis, and (3) sidewall core analysis.<ref ===Conventional or plug analysis===
  14 KB (2,121 words) - 21:16, 19 January 2022
• Migration by solution in water
  ...y. The method of transport is either through direct transport by the water or by diffusion through the water. Reservoirs formed by this type of [[Hydroca ...il. As the water mass moves into lower temperature and pressure conditions or its salinity increases, the hydrocarbons exsolve and form a free phase. Thi
  6 KB (915 words) - 15:16, 14 February 2022
• Owners of oil and gas interests
  ...r publicly owned, is reflected in the public records of the various states or, in the case of interests owned by the federal government, in the offices o ...property, and if not, they are treated in a manner that achieves the same or a similar result.
  19 KB (2,972 words) - 19:25, 19 January 2022
• Type IIS kerogen
  ...ee common source rock evaluation errors made by geologists during prospect or play appraisals]: AAPG Bulletin, vol. 93, issue 3, pp. 341-356.</ref>]]
  1 KB (205 words) - 21:10, 6 July 2015
• Tight gas reservoirs: evaluation
  ...voirs with estimated ''in situ'' gas permeabilities of 0.1 md (millidarcy) or less are officially recognized by the U.S. Federal Energy Regulatory Commis ...the occlusion of interstitial pore throats by detrital or authigenic clays or cement (see [[Rock-water reaction: formation damage]]). Thus, a proper geol
  11 KB (1,444 words) - 21:26, 4 January 2024
• Reserves estimation
  ...includes known oil and gas deposits present that cannot be technologically or economically recovered (OOIP and OGIP) as well as other undiscovered potent ...gineering data. Depending on the amount and quality of data available, one or more of the following methods may be used to estimate reserves:
  16 KB (2,550 words) - 17:47, 21 January 2022
• Forward modeling of seismic data
  ...f the earth to simulate seismic field experiments. Models can be one, two, or three dimensional and consist of depth horizons and associated P wave veloc ...verify the original interpretation. If needed, the original interpretation or model is altered and the process repeated until a desired correlation betwe
  10 KB (1,513 words) - 21:16, 19 January 2022
• Wellbore trajectory
  ...ole assembly used and the weight on the bit. The ''bottom hole assembly'', or ''BHA'', is that portion of the drill string closest to the drill bit. It c * Vertical or straight
  14 KB (2,167 words) - 20:46, 19 January 2022
• Techsteq Solution: Virus analysis and elimination
  ...p the functionality of your system. Computer viruses are a series of codes or programs that are copied without observing security standards and transmitt
  1 KB (216 words) - 08:11, 14 December 2019
• Factors that oppose hydrocarbon migration
  ...]] from high to low potential energy and are responsible for concentrating or dispersing the hydrocarbons. ...ater) is continuous. The nonwetting phase is generally assumed to form one or more continuous networks through a bed when its concentration exceeds betwe
  8 KB (1,133 words) - 15:16, 14 February 2022
• Practical suggestions for oil correlation
  ...lost much of their valuable information during cracking, phase separation, or both. ...mical data can lead to geochemically based correlations that are difficult or impossible to justify geologically.
  5 KB (718 words) - 17:24, 15 February 2022
• SEM, XRD, CL, and XF methods
  *Carbon or Au/Pd coating generally needed. ...| 10–40kV X-ray wavelength fixed. Low M.A. current || Diffraction patterns or digital files for comparison to “standards” files. || Mineralogy on sem
  11 KB (1,477 words) - 15:25, 24 January 2022
• Seismic data - creating an integrated structure map
  ...ay not work in areas with severe static problems (i.e., lots of topography or a rapidly changing weathered layer such as glacial till). It also fails whe ...d seismic time picks exist. The wells used as control do not need velocity or density logs but must penetrate the event of interest. The event depth ''z'
  7 KB (1,117 words) - 17:51, 25 January 2022
• Overpressure and hydrocarbon distribution, Gulf Coast
  ...s production from more than 20,000 wells. Most hydrocarbons are found near or slightly above the top of the overpressured zone. The chance of success is ...top seals|hydrofracturing]] rather than a simple loss of reservoir quality or other variable. Deeper reservoirs have the peak gas occurrence below the to
  4 KB (605 words) - 20:30, 30 March 2022
• Economics
  ...ity. It’s important to realize that prices of the oil resource are not set or determined by a particular company, it is subject to market forces of deman ...condition. This therefore implies that a greater number of people use oil or its related products and implies that the demand for the oil will increase
  6 KB (926 words) - 19:38, 14 March 2019
• Spontaneous potential logs in water resistivity calculation
  ...n water taken from the zone of interest at the well site or a nearby well, or it can be calculated using spontaneous potential (SP) log data.
  6 KB (1,027 words) - 16:40, 5 April 2022
• Depositional systems tract
  ...s us construct high-frequency [[Paleogeography|paleogeographic maps]], one or more for each depositional systems tract. These maps help us predict [[rese
  2 KB (215 words) - 15:43, 23 February 2022
• Rock-Eval pyrolysis
  ...large relative to S2, an alternative source such as migrated hydrocarbons or contamination should be suspected ...rbon content of the sample || Residual carbon content of sample has little or no potential to generate hydrocarbons due to a lack of hydrogen and the che
  4 KB (573 words) - 18:22, 8 February 2022
• East Breaks petroleum geology
  ...Gulf Coast Section SEPM 15th Annual Research conference, p. 245–256.</ref> or completely bypassed valley conduits subsequently filled by [[mudstone]] plu
  4 KB (494 words) - 13:44, 5 December 2023
• Land description and maps
  ...d or point on the earth is unique and distinguishable from any other tract or point—that is, if they are described in a legally sufficient manner. ...zontal surface that show the shape, dimensions, and extent of a given area or tract of land. In contrast to this, altimetric (commonly called topographic
  15 KB (2,269 words) - 19:25, 19 January 2022
• Pickett plot construction
  ...lets us compare water saturations of different parts of a reservoir in one or many wells. The Pickett plot<ref name=ch09r45>Pickett, G., R., 1973, Patter ...7.png|Figure 2]]. R_w values are published by logging companies, or we can calculate them from the SP log.
  6 KB (878 words) - 16:16, 5 April 2022
• Growth strata
  Growth or syntectonic strata are stratigraphic intervals that were deposited during [ ...thin toward the structural high. Growth strata are generally folded in one or more limbs of the structure. In [[:file:ST53_Part01_Pg11A.jpg|Figure 1]], g
  13 KB (1,930 words) - 22:28, 20 January 2016
• Pay determination
  ...ected volume of recoverable hydrocarbons from a field under a set of known or predicted economic conditions. It is of importance from the field discovery ...reservoir units that have differing fluid saturations or pore geometries, or that are present at different elevations above the Basic open hole tools [h
  13 KB (1,799 words) - 19:01, 20 January 2022
• Petroleum source rocks
  ...ass to rock mass. Thermally immature hydrogen-rich organic matter (H/C > 1 or HI > 300) has oil-generative potential, whereas lower hydrogen content usua ...leum (thermal immaturity), or it may generate petroleum (thermal maturity) or generate, expel, and overheat the residual organic matter, leaving only cha
  12 KB (1,616 words) - 17:35, 13 April 2022
• Minibasin
  ...for relationships between sedimentation and [[deformation]], like faulting or folding. [[:file:sedimentary-basin-analysis_fig4-44.png|Figure 2]] is a sch ...age of expanded sedimentary section downthrown to each major growth fault or salt high. Along the [[cross section]], the expanded section occurs in prog
  7 KB (952 words) - 18:44, 21 March 2022
• Depth and thickness conversion
  ...is the first step in arriving at a consistent representation of structural or stratigraphic data for a field in a three-dimensional grid. This is particu ...depth must be corrected to subsea depth or ground elevation (or rig floor or kelly bushing elevation) using information commonly found on log headers. F
  17 KB (2,363 words) - 16:49, 20 January 2022
• Fault-dependent leak points, continuity, and charge
  ...ly two of numerous examples. In some basins, this regional seal is lacking or limited. In the Gulf Coast, the [[North Frisco City field]] exists because
  4 KB (556 words) - 20:56, 31 March 2022
• Oilfield water analysis
  ...ue is the weight of the element in parts per million divided by the atomic or molecular weight and multiplied by the valence. In comparing waters, it is ...15–1710., 2118/951376-G</ref> The cations are plotted to the left on three or four lines, and the anions are plotted to the right. Milliequivalents are u
  7 KB (1,011 words) - 16:57, 20 January 2022
• Sandstone permeability prediction from texture
  ...sandstone [http://www.britannica.com/EBchecked/topic/369508/matrix matrix] or grains. As matrix, detrital clays can obliterate permeability. Detrital gra ...il it approaches the size of the pore throats. Throats become more tabular or sheet-like. Sandstone porosity may be quite low (<5%) and still have some p
  9 KB (1,118 words) - 17:03, 6 April 2022
• Pore throat size and connectivity
  ...s a product of the size and shape of the room. The movement of people into or out of that room is a product of the size, shape, and number of doors. A la How does one characterize the size of a pore system: by pore size or by pore throat size? Characterizing the size of a pore system by pore size
  4 KB (650 words) - 14:23, 4 April 2022
• Chromatography
  ...aphy is composed of either a solid or liquid substance attached to a glass or a metal surface on which the components of the mixture to be separated and The mobile phase in chromatography is either a liquid or gas, which is passed through a chromatographic column where the components
  15 KB (2,280 words) - 21:00, 21 April 2022
• Pressure transient testing
  * [[Permeability]] to the produced phase (oil, gas, or water), which is an average value within the radius of investigation achiev * Skin factor, which is a quantitative measure of damage or [[stimulation]] in the well
  15 KB (2,314 words) - 17:45, 21 January 2022
• AAPG Wiki:Personas
  ** Primary work location: office, field (stationary or mobile)
  1 KB (225 words) - 13:31, 6 August 2013
• Hydroelectric power
  ...icity but also those designed for flood control, irrigation, water supply, or a combination of these purposes, have delivered significant benefits, they ...arid regions with low rainfall and, therefore, with no permanent streams, or in regions of low relief. Although most of the world's sites for the buildi
  10 KB (1,466 words) - 16:06, 11 January 2016
• Morphometric and particle analysis
  ...” statistically and to relate component variability to chronostratigraphic or paleoenvironmental indices.<ref name=ch17r29>Davis, J. C., 1986, Statistics
  5 KB (718 words) - 20:59, 31 January 2022
• Cross-borehole tomography
  ...which a color is assigned to the seismic velocity at each point. This map, or plot, is referred to as a ''tomogram''. Other displays such as [[contour]] ...source borehole, and receivers are lowered to an appropriate depth in one or more boreholes that are used to record the seismic data ([[:file:cross-bore
  14 KB (2,060 words) - 20:51, 19 January 2022
• Hydrocarbon
  ...atenated carbon chain. In acyclic compounds, the carbon chain are straight or branched. Important families that belong to this group are the alkanes, alk ...opane, etc. They mainly undergo combustion under much oxygen, substitution or replacement reactions (dehydrohalogenation), and elimination (dehydrogenati
  8 KB (1,209 words) - 20:36, 20 March 2019
• Nuclear power
  ...process called fission. The nuclei of low-atomic-weight elements, hydrogen or isotopes of hydrogen, on the other hand, can be combined to form larger nuc ...fuel (i.e., convert uranium 238 into plutonium) in quantities as large as, or even larger than, the amount consumed, can be accepted and operated safely
  9 KB (1,351 words) - 15:58, 12 September 2014
• EMD Bitumen/Heavy Oil Committee
  ...al Russian oil reserves, which official estimates place at 22.5 billion m3 or 141.8 billion bbls. Recoverable heavy oil occurs in three principal petrole
  4 KB (538 words) - 20:27, 20 September 2022
• Seismic attributes
  ...smic data#Polarity|polarity]], [[phase]], [[Seismic frequency|frequency]], or [[Seismic velocity|velocity]]. [[Horizon attribute]]s were first used in th ...a horizon can, under the correct circumstances, be related to [[porosity]] or net pay in a reservoir interval. With other attributes the physical interpr
  6 KB (859 words) - 19:42, 27 January 2022
• Petroleum exploration
  ...nt in relatively small quantities within the earth. These source rocks can or can not be a reservoir rock. The concept of reservoir rock is a storage tha ...impermeable rock. If the fluids continue to migrate when there is no trap or seal, it would go to the surface and dissipate.
  15 KB (2,331 words) - 19:12, 17 April 2019
• Weyburn seal capacity
  ...r critical nonwetting phase saturation. Clearly, estimating R_bt or the size of the largest connected pore throats that control hydrocarbon bre ...thod yields pore throat sizes representative of that mode of pore throats, or R_bt.
  10 KB (1,484 words) - 20:55, 4 December 2023
• Glossary
  ;DF:derrick floor or drilling fluid ;FL:fluid or fluid level
  5 KB (840 words) - 13:51, 18 March 2019
• Drilling a well
  ...e rotating bit cuts or crushes the rock. Drilling mud, consisting of water or an oil-water mixture, solids, and various additives, is circulated down thr ...floor. In moderately deep water (more than 45 m [150 ft] deep), a floating or semisubmersible rig is used. The semisubmersible rig is kept in place by se
  15 KB (2,385 words) - 15:05, 1 August 2016
• Well completion
  * Connect the reservoir to the surface so that fluids can be produced from or injected into the reservoir ...ngle perforated casing completions are used; however, multiple, alternate, or slim hole completions may be used under certain conditions. The choice of c
  19 KB (2,910 words) - 21:06, 18 January 2022
• Plate tectonic studies
  ...the area may have been affected by more than one [[deformation]] event and/or more than one deformational style * Independent or “spec” regional studies integrating all aspects of the petroleum geolog
  4 KB (601 words) - 18:22, 2 February 2022
• Depocenter
  '''Depocenter''' refers to an area or site of maximum deposition, or the geographic location of the thickest part of any specific geographic uni ...rfaces bounding each tectonostratigraphic phase and construct isopach maps or relative thickness maps.
  6 KB (811 words) - 16:50, 22 February 2022
• Marine seismic data acquisition
  ...rray designer. ''Clustered guns'' are another recent advancement. When two or three air guns are fired in close vicinity of one another, it is possible t ...''strings'') are deployed in various geometries to improve directivity and/or to reduce shot generated noise. The simple wide array is common and very ef
  13 KB (2,015 words) - 18:24, 21 January 2022
• Coal bed methane (UB)
  ...l is constructed in an environment with low oxygen content, such as swamps or bogs. Coal is easily known by its black color. Furthermore, if seen under a Most CBM has been produced by microbial, thermal, or possibly catalytic degradation of organic material present in coal. CBM is
  5 KB (839 words) - 17:19, 28 March 2019
• Multivariate data analysis
  ...le, a porous medium is characterized by a set of interdependent quantities or attributes such as [[grain size]], [[porosity]], [[permeability]], and satu ...es; P), where n is the number of samples and P is the number of attributes or variables. For example, a (5 &times; 3) matrix might represent five core sa
  16 KB (2,349 words) - 15:46, 19 January 2022
• Geothermal energy
  ...ed mainly as the fuel for the operation of electricity-generating turbines or for space heating. ...ial from the [[mantle]] is being added to the [[crust]] (spreading ridges) or where crustal material is being dragged downward and consumed in the mantle
  13 KB (1,918 words) - 18:12, 2 April 2019
• Determining water saturation
  ...can be measured directly from a sealed core, which is an expensive method, or it can be calculated from the [[Archie equation]],<ref name=Archie_1942>Arc
  2 KB (244 words) - 13:38, 5 April 2022
• Perforation design
  ...expectation of connecting the well to the reservoir. Usually the pay zone or interest zone is the target for perforation. This will allow the communicat ...A primary explosive that can be initiated by either an electrically signal or an impact reaction.
  12 KB (1,786 words) - 21:02, 21 April 2022
• Checkshots and vertical seismic profiles
  ...rtical-seismic-profiles_fig3.png|{{figure number|3}}The source position (A or B) should be chosen so that the travel path to each receiver is as nearly v ...in this diagram, but other common onshore energy sources include Vibroseis or air guns operated in a water-filled pit near a well. Offshore, essentially
  11 KB (1,599 words) - 20:48, 19 January 2022
• Coalbed methane
  ...ccur as free gas in [[fracture]]s (called [[cleat]]s) and large pores, and/or dissolved in the groundwater present in pores and fractures; coal serves as ...by some that interest in the production of coalbed methane would decrease or even die with the termination of the tax credit at year-end 1992, but this
  5 KB (691 words) - 21:13, 19 November 2015
• Statistics overview
  ...to formal statistical inference, geological samples are much too difficult or costly to obtain and cannot be discarded. Therefore, the robust testing of ...a data set composed of well information, if the kelly bushing is not known or uniformly subtracted from all wells, the resulting map will develop a sever
  16 KB (2,483 words) - 19:28, 19 January 2022
• Vitrinite reflectance
  ...does not accurately represent the maturity of the rock sample. Variations or errors in vitrinite reflectance measurements may be caused by the following A bimodal distribution or a large spread in the range of measured values will produce a mean R<sub>o<
  7 KB (970 words) - 14:28, 10 February 2022
• Seismic processing basics
  ...data taken in the field are reduced to simple images for display on paper or the work station screen. This simple image, while it contains less data abo ...f the earth, an elapsed time after the shot that originated the reflection or echo (traveltime), and a reflection point on the subsurface of the earth at
  19 KB (2,895 words) - 20:23, 21 January 2022
• Structural play geology
  ...audi Arabia (560,000 ac)] to small [Major County, Oklahoma, U.S.A. (160 ac or less)].<ref>J. Coughlon, personal communication, 1996</ref> To effectively * [[Deformation]] or [[diagenesis]] of reservoirs and seals ([[trap]] integrity)
  18 KB (2,422 words) - 14:21, 2 February 2022
• Karst topography
  ...racterized by the vast, bare, and rocky land, without arable land and with or without the presence of veregetation. ...soil covered karst is karst that develops in [[limestone]] covered by soil or terra that produced by limestone dissolution.
  13 KB (2,016 words) - 19:56, 5 April 2019
• Black Warrior basin
  ...as province with numerous possible reservoir units. Oil and gas have been, or presently are, produced from the [[Cambro-Ordovician]], [[Ordovician]], [[M
  2 KB (308 words) - 16:53, 26 March 2015
• Wellsite math
  | V_h || Hole volume; the volume of the open or cased hole || bbl/ft ...ulus, the area between the outside of the drillpipe or collar and the open or cased hole || bbl/ft
  21 KB (3,142 words) - 15:10, 24 January 2022
• Near-surface destruction
  ...active meteoric water circulation because the water supplies the oxidants or nutrients. ...selectively strips the oil of components up to a carbon number of about 15 or so. This process can account for destruction of up to 50% of the mass of th
  8 KB (1,193 words) - 18:51, 1 February 2022
• Structural geology
  [[Growth fault]]s are syndepositional or synsedimentary extensional faults that initiate and evolve at the margins o ...ithin passive margin sedimentary wedges where tectonic forces have minimum or no effect. These passive margins receive millions of tons of sediments ever
  14 KB (2,168 words) - 21:31, 13 March 2019
• Drilling fluid
  An essential element of [[drilling a well]] is the drilling fluid or mud. Drilling fluids serve a number of functions: The most important feature of any drilling fluid (or mud) system is that the interaction between the mud and the drilled formati
  13 KB (1,866 words) - 21:17, 19 January 2022
• Subsurface diagenesis and its relation with diagenetic trap on carbonate rocks reservoir
  ...n in water saturated condition produces mold, vein, hole, and channel with or without the breakdown of this appearance (associated with cave and karst ge ...e occurs, is causing a stable reaction which changing metastable carbonate or the other stable reaction (recrystallization, includes neomorphism). Weathe
  16 KB (2,395 words) - 21:18, 9 January 2024
• Weyburn field location and trap problem
  ...stion: Could the Midale marly beds provide a seal for a 600-ft oil column, or must hydrodynamics be present to augment the seal quality of the Midale mar
  6 KB (848 words) - 17:34, 3 January 2024
• Three-dimensional seismic method
  ...in the [[Gulf of Mexico]] to delineate salt domes. Shooting around a lake or a topographic high to achieve subsurface coverage under the surface obstacl ...[[length::1 km]], the line spacing in 3-D surveys can be [[length::50 m]] or less. This dense coverage requires an accurate knowledge of shot and receiv
  8 KB (1,201 words) - 20:24, 21 January 2022
• Surficial geochemistry and hydrocarbon detection methods
  * Gas adsorbed onto sedimentary particles or trapped within carbonate cements * Gas dissolved in water or present in the atmosphere
  10 KB (1,443 words) - 16:08, 25 January 2022
• East Breaks hydrocarbon generation model
  ...nally, basins are 3-D entities, and either 2-D models throughout the basin or a 3-D model of the entire basin is essential to understanding the maturatio
  6 KB (850 words) - 15:33, 23 March 2022
• Magnetics: interpreting residual maps
  ...dimentary section in a new basin, i.e., in determining whether it is 2, 5, or [[length::10 km]] thick, for example, to a usual accuracy of about ±15% un ...(B–B′). This may be a strike-slip fault, which is not common in this area, or another down-to-the-east fault that has down-dropped the four anomalies ben
  8 KB (1,109 words) - 17:41, 24 January 2022
• Israel petroleum systems
  ...Rock || Produced by 2001 (MMBO &/or BCFG) || Recoverable Resources (MMBO &/or BCFG) | || 22 || Or || Yafo || 1999 || Yafo Sand || Turbidite sandstone || Gas || Stratigraphic
  10 KB (1,276 words) - 21:00, 19 July 2016
• Tool table
  ...for the standard logging tools. Service companies have specially designed or modified tools that may allow extension of operation ranges.
  5 KB (544 words) - 16:27, 18 January 2022
• Temperature trap regime
  Temperature traps are those in which trap boundaries are created or controlled by subsurface temperatures. Both low temperatures and high tempe
  2 KB (260 words) - 16:31, 13 April 2022
• Reservoir simulation study
  ...by the number of grid blocks resulting from the grid overlain on the field or field segment being studied. In general, the accuracy of results from simul ...he mechanics of production performance (such as viscous flow, [[gravity]], or heterogeneity). For example, a fluid injection project can be studied using
  19 KB (2,711 words) - 17:48, 21 January 2022
• Show evaluation
  ...tion testing, setting pipe, participation elections, and lease acquisition or relinquishment. * Detection of formation [[Natural gas|gas]] or [[Oil as an energy source|oil]]
  18 KB (2,670 words) - 18:21, 21 January 2022
• Rock-water reaction
  ...ervoir rock with extraneous [[drilling]], [[completion]], [[stimulation]], or [[enhanced recovery]] fluids. Rock-fluid reaction can occur from any of the # [[Injection]] or production of fluids at rates exceeding the critical velocity beyond which
  17 KB (2,356 words) - 19:24, 19 January 2022
• Reservoir quality
  ...es in a rock. The remaining space in the rock is occupied by the framework or matrix of the rock and, if present, nonconnected pore space. Common porosit | Dissolution or vug
  18 KB (2,514 words) - 17:47, 21 January 2022
• Rock-water reaction: formation damage
  ...the reservoir rock with extraneous drilling, completion, [[stimulation]], or enhanced recovery fluids. Rock-fluid reaction can occur from any of the fol * Injection or production of fluids at rates exceeding the critical velocity beyond which
  17 KB (2,380 words) - 18:23, 21 January 2022
• Two-dimensional geophysical workstation interpretation: generic problems and solutions
  ...ut the workstation are made here: no hardware constraints exist for memory or storage and an efficient database manager exists for data manipulation. A d ...display types (such as stack, [[seismic migration|migration]], inversion, or attribute) is facilitated by creating several data files, each containing a
  20 KB (2,848 words) - 14:29, 20 January 2022
• Cross section
  ...rough the earth used to clarify or interpret geological relationships with or without accompanying maps. As with other tools applied to [[petroleum]] dev ...[[deformation]] by showing the drape of sediment over developing [[fold]]s or the thickening of the section across [[growth fault]]s. The following eleme
  20 KB (3,029 words) - 16:09, 24 January 2022
• Apatite fission track analysis
  ...n geologic history of an area (and its expected thermal history) to verify or refine a vendor's interpretation. ...tracks would have formed since the uplift to a temperature zone less than or equal to the [[temperature::60&deg;C]] to [[temperature::70&deg;C]]. The fi
  7 KB (994 words) - 21:38, 4 February 2022
• What is permeability?
  ...ements is important for understanding how to assess reservoir rock quality or to compare the quality of one flow unit to another. ...laminations. High vertical K_a generally results from fracturing or even burrowing that cuts across bedding. Most K_a calculations ar
  5 KB (694 words) - 20:41, 4 April 2022
• Static gas pressure gradient estimation
  ...gas pressure gradients can be estimated if subsurface gas density is known or has been estimated. ...ow this procedure to estimate the gas pressure gradient of a gas reservoir or potential gas reservoir.
  7 KB (979 words) - 15:24, 17 February 2022
• Core alteration and preservation
  ...rals and fluids. For example, the filtrate may cause clays either to swell or to shrink. ...nd expulsion by the retention of the expulsed formation fluids in a sponge or foam lining.
  20 KB (2,971 words) - 15:46, 19 January 2022
• Superimposed sea level cycles
  ...se with third-order transgressions, the impact that each has on deposition or erosion is enhanced.<ref name=ch04r70>Mitchum, R., M., Jr., Van Wagoner, J. ...her order, the patterns of transgression vs. [[regression]] either amplify or dampen the transgressions and regressions of the next higher order(s) of cy
  11 KB (1,469 words) - 15:06, 5 January 2024
• Combining well log with seismic sequence analysis
  ...tratigraphic-traps_fig21-22.png|Figure 1]]) using the appropriate software or by asking an expert to create one. [[Synthetic seismogram]]s, or synthetics, can be interactively tied to log, lithologic, and seismic data
  5 KB (746 words) - 16:54, 4 February 2022
• Standard interpretation
  ...rocess of determining volumes of hydrocarbons in place from wireline logs, or [[log interpretation]]. This process requires four basic steps: ...of the various logging devices. To interpret the response for [[porosity]] or saturation, the volume of shale must be determined.
  25 KB (3,776 words) - 19:53, 18 January 2022
• Shale tectonics
  ...as intrusive injectites or [[diapir]]s or as extrusive eruptive sand blows or mud volcanoes has captured the public's imagination and given scientists th ...id leakage from overpressured beds, but they do not always involve plastic or fluid-mud extrusion. Shales form a variety of nonextrusive structures, many
  17 KB (2,466 words) - 16:16, 10 January 2024
• Log analysis applications
  ...nstant increment (usually based on the smallest common sampling increment) or (2) by varying increments (based on each trace's unique sampling nature). Log analysis packages should allow the user to do any or all of these in the order deemed appropriate by the user.
  21 KB (3,142 words) - 16:20, 20 January 2022
• Strain partitioning
  ..., J., J. Cosgrove, and E. Druguet, 2013, Strain partitioning in banded and/or anisotropic rocks: Implications for inferring tectonic regimes: Journal of All four of these factors below may individually or in combination contribute toward the distribution of strain. Therefore, eac
  13 KB (1,732 words) - 22:01, 23 January 2019
• FWhitehurst sandbox
  ===Definitions and/or links for future use=== * angular unconformity or discontinuity Wikipedia:Unconformity#Angular_unconformity
  22 KB (3,024 words) - 21:42, 19 December 2014
• Risk: expected value and chance of success
  ...recommended procedure is for the geotechnical professional to express his or her confidence independently in four critical geological aspects of any pro ...o contain detectable (i.e., measurable) quantities of mobile hydrocarbons, or to tempt a prudent onshore domestic operator to attempt a completion?''
  22 KB (3,173 words) - 19:27, 19 January 2022
• Structural analogies
  ...t]], but local [http://www.merriam-webster.com/dictionary/outcrop outcrop] or subsurface data do not accurately define the shape of individual structures
  4 KB (579 words) - 20:52, 2 February 2022
• Core description
  ...a visual pattern such as that produced by Amstrat. A good qualify handlens or reflecting light binocular microscope are essential for accurate grain size ...in]] (1.3 mm) high. Usually a scale of [[length::1 in]] = [[length::5 ft]] or [[length::10 ft]] is appropriate.
  13 KB (1,786 words) - 20:50, 19 January 2022
• Economics of property acquisitions
  ...ucing properties for purchase as they are to oil and gas drilling ventures or development projects. As before, it is assumed that the data and estimates ...llowing rapid estimation of remaining reserves of a producing well, lease, or field, and it can be useful in early assessments and negotiations. A compre
  11 KB (1,584 words) - 16:04, 21 January 2022
• Petroleum system concept: examples of application
  ...ture downdip to the north, then drill the deepest prospect, not the middle or shallowest prospect to the south. &copy; Barker.<ref name=Barker1992>Barker ...dip to the north, then we would drill the deepest prospect, not the middle or shallowest prospect to the south ([[:file:petroleum-systems_fig3-22.png|Fig
  7 KB (1,083 words) - 21:59, 25 January 2022
• Fluid contacts
  ...m/en/Terms.aspx?LookIn=term%20name&filter=oil-water%20contact oil-water]'' or ''[http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&fi ...well logs]] || Estimates fluid contacts from changes in fluid saturations or mobility with depth || Low cost Accurate in simple lithologies || rowspan =
  19 KB (2,690 words) - 21:20, 19 January 2022
• Seal capacity: pitfalls and limitations of estimation
  ...al displacement pressure|displacement pressure]] of a top seal from a few, or many, measurements.
  2 KB (325 words) - 20:57, 31 March 2022
• Geology workstation
  ...atabases. The third approach has been the explosion in personal computers, or PCs, over the past decade. Initially only offering what could be termed bus Today, the geologist is likely to have a hybrid of any or all of the above, often with everything from PC to mainframe networked toge
  19 KB (2,872 words) - 14:28, 20 January 2022
• Gravity basics
  * Locating structures under thrust plates or volcanics In dynamic gravity measurements at sea or in the air, the position of the mass and the spring tension is recorded con
  5 KB (720 words) - 17:59, 24 January 2022
• Methods for obtaining formation fluid pressures
  * Calculating hydrostatic pressures from measured water density or salinity
  2 KB (295 words) - 17:54, 17 February 2022
• East Breaks deep-water exploration strategy
  ...optimally located. Additionally, seismic facies maps may suggest downflank or off-structure potential where faulting may not impose development problems. # Use seismic facies maps to identify downflank or off-structure potential where faulting may not impose development problems.
  6 KB (902 words) - 16:00, 24 March 2022
• Borehole imaging devices
  ...a bedding surface, fracture, or fault shows up as a sinusoid. The minimum, or trough, of a sinusoid points in the direction of the [[dip]] [[azimuth]], w Most borehole images are digitized, either downhole or uphole, and are thus amenable to digital computer processing such as image
  10 KB (1,313 words) - 16:24, 18 January 2022
• Great American carbonate bank
  ...rred during deposition of the Early Ordovician Symphysurina trilobite Zone or during deposition of the Cordylodus angulatus and basal Rossodous manitouen ...ately 16 MMBO and 160 bcf/year. Hydrocarbon production occurs primarily at or near the Sauk-Tippecanoe [[unconformity]], in association with source rock
  5 KB (768 words) - 18:39, 1 August 2016
• Sea level cycle order
  ...sited during those cycles have to each other. Knowing the order of a cycle or the phase of a cycle represented by a rock sequence is important for predic ...ext of the sequence. What are the cycle orders for similar sequences above or below it?
  7 KB (982 words) - 21:20, 23 February 2022
• Fracture analysis
  * In some cases, determination of the fluid or mineral filling in fractures Fracture analysis can help us define structural axes and trends or fracture-related reservoir properties. It can be applied in a variety of st
  5 KB (644 words) - 15:30, 3 February 2022
• Stimulation
  ...lity, but the formation near the wellbore has been damaged by the drilling or completion process. ...atrix acidizing but may occasionally involve hydraulic fracturing. Solvent or surfactant treatments are sometimes used for damage removal.
  24 KB (3,633 words) - 13:55, 24 January 2022
• Fractured reservoir evaluation
  ...(1) increased reservoir [[permeability]], (2) increased [[porosity]], and/or (3) increased permeability [http://wiki.seg.org/wiki/Dictionary:Anisotropy | Reservoir performance is controlled by sedimentary facies, lithology and/or geometry || Determine sedimentary characteristics and origin of facies thro
  26 KB (3,674 words) - 21:21, 19 January 2022
• Saturations required for hydrocarbon flow
  ...re at only 10% saturation could be very misleading. The value could be two or more orders of magnitude greater than that predicted at 10% saturation.
  2 KB (313 words) - 13:57, 1 April 2022
• Sediment thickness and field location maps: Gulf of Mexico example
  ...cumulation—the space resulting from the interaction of tectonic subsidence or uplift, sea level change, and compaction of the underlying sediment. Additi ...of these lateral shifts result from tectonic events along the basin margin or within the drainage basins themselves.<ref name=ch04r34>Galloway, W., E., 1
  5 KB (753 words) - 19:58, 18 February 2022
• Fluid flow fundamentals
  ...or it can be predicted from reservoir data. Whether presented graphically or expressed by a formula, the IPR is a statement of the production capacity a ...uced for every psi of pressure drawdown and thus reflects the productivity or deliverability of the well.
  20 KB (3,155 words) - 21:20, 19 January 2022
• Synthetic seismogram
  ...rom the sonic velocities and the density data. The data are often averaged or “blocked” to larger sample intervals to reduce computation time and to ...tween the seismic line trace and the synthetic seismogram. A formation top or other correlation marker on the well log can then be tied to the correspond
  8 KB (1,199 words) - 13:57, 24 January 2022
• Structurally complex reservoirs: evaluation
  ...er, and they should be tested for viability and admissibility by balancing or [[backstripping]]. ...ll have to be projected carefully onto the lines using seismic cross lines or down-plunge projection.<ref name=DePaor_1988>DePaor, D., 1988, [http://arch
  20 KB (2,865 words) - 19:24, 19 January 2022
• Magnetotelluric data acquisition
  The controlled-source system uses a high-power transmitter and motor or generator set to transmit a discrete alternating current waveform. This sig ...,000 ft) in a typical [[Wikipedia:Volcanic_rock|volcanic]], [[carbonate]], or [http://geology.about.com/od/more_igrocks/a/granite.htm granite] [[Thrust b
  5 KB (706 words) - 15:11, 31 January 2022
• Wettability
  * Measurement of the contact angle, or the product of the contact angle and the interfacial tension (the last term * Observations of displacement or surface phenomena associated with the water or oil phase
  12 KB (1,706 words) - 15:11, 24 January 2022
• Using conventional well logs to estimate richness
  ...[[Total organic carbon (TOC)|total organic carbon (TOC)]] using pyrolysis or another suitable measurement technique. Using the calibrated logs, we can e | Gamma ray (GR) or uranium (U) || High || High GR caused by U; can be linear with OM; U not al
  5 KB (768 words) - 15:48, 9 February 2022
• Magnetics
  ...15 to 25 miles of rock are involved. Most sedimentary rocks contain little or no magnetite, and the crystalline [[basement]] rocks are by far the most im ...ric currents in the core. The intensity of the field is measured in gammas or the equivalent SI unit of nanoteslas (nT), and it varies from about 60,000
  10 KB (1,481 words) - 15:39, 24 January 2022
• Systems tracts and trap types
  ...ofacies of the lowstand systems tract might occur as subunconformity traps or might be mistakenly identified as highstand systems tract deposits. [[Gravi ...ng in volumetrically smaller reservoirs. Traps can be purely stratigraphic or enhanced with postdepositional structuring that focuses migration.<ref name
  9 KB (1,239 words) - 16:58, 24 February 2022
• Reservoir
  ...of the elements of petroleum system that can accumulate hydrocarbons (oil or gas). Reservoir rock must have good porosity and permeability to accumulate ...um (oil and gas), water, a range of non hydrocarbon gasses (CO2, H2S, N2), or some combination of these.<ref name=gluyas2004> Gluyas, J., and S. Richard,
  14 KB (2,134 words) - 16:48, 26 March 2019
• Borehole gravity tool
  ...ed to an operator at the surface. Because of vibrations, seismic activity, or residual tool movement, the measurements may take some time to settle to an ...vertical to make a reading, it can only measure in wells of 14° deviation or less.
  5 KB (720 words) - 18:07, 24 January 2022
• Biodegradation of crude oil in reservoirs
  ...vity. Under the right conditions, living organisms such as bacteria, algae or fungi are able to consume hydrocarbons as an energy source. The process is ...) affecting organic matter. This process can occur in petroleum reservoirs or during migration at shallow depths where water contact is possible and subs
  16 KB (2,354 words) - 18:16, 25 April 2022
• Sequences during high-amplitude, high-frequency cycles
  ...lomitized sequences that consist of inner platform highstand sabkha facies or late highstand to low stand [[evaporite]] basin facies ...e related to diagenesis. In this example, sequences lack internal barriers or seals to inhibit the vertical and lateral migration of the paleowater table
  6 KB (761 words) - 13:47, 7 April 2022
• Quantitative fault seal analysis
  ...f the sand–shale ratio is high in the zone (high SGR). A fault cross-seals or dip-seals if the sand–shale ratio is low in the zone (low SGR).
  9 KB (1,327 words) - 16:32, 29 March 2022
• Ti in zircon geothermometer
  '''Zircon Titanium Geothermometry''', or "Ti-in-zircon [[Geothermometry]]" is a technique by which the crystallizati ...in detail. Ti⁴⁺, a tetravalent ion, can replace Zr⁴⁺ or Si⁴⁺ in a temperature dependent mechanism. For zircons in the pr
  16 KB (2,328 words) - 22:11, 3 December 2015
• Formation evaluation of naturally fractured reservoirs
  ...ractures. This tool operates with transmitter-receiving spacings of 8, 10, or [[length::12 ft]] and emits acoustic energy that propagates radially throug ...esence of natural [[fracture]]s. Thus, caliper tools (two-, three-, four-, or six-arm) can provide good indications of fractures.
  9 KB (1,380 words) - 17:25, 18 January 2022
• Organic facies
  ...s, palynofacies, pollen facies, [[kerogen]] facies, organic matter facies, or [[maceral]] facies. They cannot be determined by microscopy alone. The defi ...sedimentary rocks occurs whether or not rocks are organic rich and whether or not the fine-grained sediments are well cemented. Weathering often penetrat
  17 KB (2,472 words) - 17:39, 13 April 2022
• Seismic data - mapping with two-dimensional data
  ...y of any part of the base map, consult with the person who drafted the map or check the field records yourself. ...for your interpretation, refer to the person who drafted the map for help or check the field records yourself.
  13 KB (1,936 words) - 21:29, 21 January 2022
• AAPG Wiki:Project timeline
  ...no figures in digital format; they will have to be extracted from the PDF or redrawn (preferable, where possible).
  2 KB (333 words) - 18:09, 15 July 2013
• Capillary pressure (Pc) curves: pore throat size determination
  ...Real pores only approximate this, and then only if they are intergranular or inter crystalline.<ref name=CoalsonPC>Coalson, personal communication, 1997 ...mercury at this point in the test have at least one 10μ pore throat radius or larger and represent 10% of the sample's pore volume. This procedure is rep
  6 KB (898 words) - 16:21, 4 April 2022
• Well log analysis for reservoir characterization
  ...1-Flowchart to analyze well logs that must be done to characterize an oil or gas reservoir, the user should follow these steps in order to acquire the c ...ally, a formation with high gamma ray reading indicates that it is a shaly or shale, when the low gamma ray reading indicates a clean formation (sand, ca
  25 KB (3,679 words) - 21:17, 13 March 2019
• Natural hydraulic fracturing of top seals
  * σ₃ = effective least principal stress or confining pressure ...ke care since leak-off tests may report the pressure value either prior to or after the fracture pressure point.<ref name=ch10r23>Eaton, B. A., 1969, Fra
  9 KB (1,274 words) - 15:44, 30 March 2022
• Flow units for reservoir characterization
  ...'A flow unit is a specific volume of a reservoir, which is composed of one or more [[reservoir quality]] lithologies and any nonreservoir quality rock ty ...consistent, but not necessarily homogeneous, in terms of either geological or petrophysical properties. They may contain more than one reservoir quality
  16 KB (2,282 words) - 20:46, 19 January 2022
• Thin section analysis
  ...ft). (E) Gas-stage TSR calcite (yellow arrow), with no evidence of bitumen or oil inclusions found in this type of calcite, suggesting that calcite was f ...formation damage]] that can be caused by [[Wellcompletion|completion]] and/or [[stimulation]] procedures.
  24 KB (3,264 words) - 15:09, 24 January 2022
• Seismic data: identifying reflectors
  Whether using[[vertical seismic profile| VSP]], [[synthetic seismogram]], or [[log overlay]], the final step is to compare the object to [[seismic trace
  2 KB (348 words) - 19:10, 27 January 2022
• Petroleum reservoir fluid properties
  ...erally assumed that reservoir fluids are in a static state when discovered or, more correctly, that fluids are moving at a very slow rate relative to the ...servoir conditions, relative to the volume of a surface phase (water, oil, or gas) at standard conditions resulting when the reservoir material is brough
  19 KB (2,721 words) - 21:21, 19 January 2022
• Geologic mapping (UGM)
  ...that’s most competent and is used for various purposes either for science or exploration of natural resources. A geological map is a map that consists o ...While smart mapping is done by considering the results of satellite image or topographical maps analysis, so it would be more efficient in geological ma
  29 KB (4,733 words) - 15:34, 15 January 2024
• Amplitude versus offset (AVO) analysis
  ...el|elastic layered model]] of the earth in the vicinity of the exploration or development target. To accomplish this goal, a systems approach to the prob Whether or not there is an application for [[amplitude]] versus [[offset]] analysis in
  12 KB (1,723 words) - 18:41, 20 January 2022
• Sea level cycle phase and systems tracts
  ...be related to rise and fall in lake level or water table level, which may or may not be synchronized with sea level change. [See Wheeler<ref name=ch04r1 Deposition or erosion of sediments depends on the interaction of cycle phase and the crea
  8 KB (1,103 words) - 21:21, 23 February 2022
• Migration by separate phase
  Slug flow (or bulk phase flow) is generally accepted as the dominant mechanism of primary ...[[Hydrocarbon migration|migration]] occurs when a gas is expelled with oil or migrates through an oil-rich source rock. The figure below shows the gasoli
  8 KB (1,155 words) - 15:17, 14 February 2022
• Biostratigraphic applications in hydrocarbon exploration
  ...igraphy is used to identify rock formations which can occur at outcrop and/or in the subsurface and correlate time-equivalent units over large distances ...ber|2}}Main microfossils disciplines that are used in the oil industry and/or paleoenvironmental use (Avada Oil and Gas Course).]]
  14 KB (1,899 words) - 21:03, 21 April 2022
• LECO method in estimating richness
  ...of carbon dioxide is directly proportional to the amount of organic carbon or the TOC of the rock. However, the TOC value can be inflated due to the pres
  2 KB (354 words) - 15:49, 9 February 2022
• East Breaks source rock
  ...ion to a probable source rock are used to determine the level of certainty or the confidence that an oil originated from a specific source. Oils from the ...cene to lower Eocene Wilcox Formation. If lower Tertiary Wilcox equivalent or uppermost Jurassic mudstones are the source for hydrocarbons in the East Br
  7 KB (1,080 words) - 17:44, 23 March 2022
• Magnetic field: local variations
  ...magnetic response of elevation changes in basement caused by fault throws or basement highs unless basement is deep (> [[length::5 km]], approximately). The presence of a fault is a common interpretation of a magnetic increase or decrease. This interpretation assumes the fault throw, which changes the el
  6 KB (946 words) - 19:56, 27 January 2022
• Kerogen
  ...ee common source rock evaluation errors made by geologists during prospect or play appraisals]: AAPG Bulletin, vol. 93, issue 3, pp. 341-356.</ref>]] ...Four basic types of kerogen are found in sedimentary rocks. A single type or a mixture of types may be present in a source rock. The table below lists a
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• Seismic scale importance
  Correlations with well data, such as cuttings, cores, or well logs, can be done to a much higher resolution than seismic scale corre
  2 KB (346 words) - 21:06, 3 February 2022
• Borehole gravity: uses, advantages, and disadvantages
  * Is unaffected by [[washout]]s, [[hole rugosity]], or [[mud invasion]] effects
  3 KB (351 words) - 15:11, 31 January 2022
• Stable isotope stratigraphy
  ...representing isotopic values through time can provide a basis for regional or even worldwide correlations. Although biotic and diagenetic effects must be ...ore or [http://www.merriam-webster.com/dictionary/outcrop outcrop] samples or from well cuttings in areas of relatively high sedimentation rate may help
  9 KB (1,282 words) - 20:59, 31 January 2022
• Vibro-sesismic to increasing the production rate of coal bed methane
  Porosity is the space that exist within rocks or materials, meanwhile pearmebility is the capacity of pore material to let f ...tential energy . this system have capability to save kinetic energy (massa or inertia). Vibration system involve ac-dc transfer energy beetwen potential
  11 KB (1,551 words) - 16:49, 11 January 2016
• Paleontology
  ....com/od/geotime_dating/a/timeyardstick.htm isotopic ages] from interbedded or cross-cutting rocks such as [http://geology.campus.ad.csulb.edu/people/bper ...eroded, environmental conditions prevented the species from living there, or the specimens may have dissolved. If a species is not abundant at the top o
  17 KB (2,331 words) - 20:11, 10 August 2016
• Mapping paleogeography
  ...you need to map the paleogeography at the level of a depositional sequence or a [[Systems tracts and trap types|systems tract]]?
  3 KB (346 words) - 20:13, 4 February 2022
• Paleoenvironmental analysis
  The aim of paleoenvironmental analysis, or paleoecology, is to reconstruct the biological, chemical, and physical natu | Species distribution and abundance of climatically or oceanographically sensitive fossils: calcareous nannofossils, planktonic an
  10 KB (1,252 words) - 19:55, 31 January 2022
• Production Index (PI)
  ...ak includes nonindigenous [[hydrocarbon]]s, such as [[drilling additive]]s or [[Migration|migrated]] hydrocarbons. Expulsion characteristics of a [[sourc
  3 KB (364 words) - 16:10, 10 February 2022
• Uncertainties impacting reserves, revenue, and costs
  | Availability || Recent or spectacular examples are more prone to be cited, regardless of their real f # ''Motivation,'' which leads to overestimates because of career or economic self-interest on the part of the professional in "selling the deal
  21 KB (3,123 words) - 19:27, 19 January 2022
• Subsurface maps
  ...aps and sections, in Petroleum Geology: New York, John Wiley, 660 p.</ref> or “high technology” [[computer contouring hardware/software systems]],<re ...l is a useful reference datum. Commonly contoured horizons are top of zone or top of net pay. Control points are provided by surveyed wells and can be su
  22 KB (3,076 words) - 13:56, 24 January 2022
• Overpressure causes
  ...at]], [[compaction]], [[Petroleum generation|generation of hydrocarbons]], or a combination of these factors.
  3 KB (394 words) - 16:23, 16 February 2022
• Geological heterogeneities
  ...eneities have been classified in a variety of ways according to their size or scale; the common categories, used here, are ''wellbore, interwell'', and ' ...ermeability profiles of (a) fining- or thinning-upward and (b) coarsening- or thickening-upward sequences. ''Fining'' and ''coarsening'' refer to average
  17 KB (2,232 words) - 21:22, 19 January 2022
• Formation fluid pressure from repeat formation testers
  | Sampling interval || Small || Several feet or more; generally tests multiple flow units ...hydrostatic and formation pressure at the well site to recognize anomalies or tool errors and to optimize station coverage.
  6 KB (849 words) - 17:55, 17 February 2022
• Artificial lift
  ...p is adjusted by changing the number of stages in the centrifugal pump and/or by changing the horsepower of the electric motor. ...additional lift. Gas lift systems can be installed to operate continuously or intermittently. Gas lift is commonly used in offshore applications and in a
  7 KB (1,094 words) - 20:47, 19 January 2022
• Contourites
  ...nce. These currents may flow upwards, downwards, around or above obstacles or irregular topographies. ...al slope or the continental rise. Along-slope processes may generate drift or contouritic features. The latter are less known than the former, which are
  13 KB (1,889 words) - 19:11, 6 April 2016
• Diagenetically complex reservoir evaluation
  ...iagenetic alteration may lead to the need to drill additional infill wells or reposition the locations of such wells, selectively perforate and inject re ...s must exhibit a complex distribution that is not directly correlated with or controlled by depositional factors.
  31 KB (4,171 words) - 18:22, 21 January 2022

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