Search results

• 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.
  2 KB (311 words) - 16:11, 2 April 2014
• 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.
  3 KB (355 words) - 15:18, 17 February 2022
• Suggested pages
  ** [[Historic plays or fields]] ...t have enough material to properly discuss a topic and need to be added to or completed.
  2 KB (215 words) - 20:43, 10 August 2015
• 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
  5 KB (737 words) - 17:01, 9 October 2013
• 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
  3 KB (373 words) - 19:06, 27 January 2022
• 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.
  3 KB (478 words) - 17:09, 1 February 2022
• 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
  453 bytes (78 words) - 20:55, 27 August 2014
• 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.
  4 KB (545 words) - 18:52, 3 February 2022
• 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
  3 KB (426 words) - 14:51, 16 February 2022
• 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.
  4 KB (618 words) - 19:40, 14 February 2022
• Underpressure causes
  Underpressure can be caused by [[burial]] or [[heat]] decrease. ...y [[impermeable]] rocks, it becomes underpressured by burial when faulting or downwarping occurs.
  3 KB (390 words) - 16:23, 16 February 2022
• 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
  2 KB (258 words) - 18:41, 31 March 2022
• Inertinite
  ...maceral]] group composed of inert hydrogen-poor organic matter with little or no petroleum-generative potential. Type IV [[kerogen]] is dominated by iner
  688 bytes (93 words) - 19:04, 14 March 2016
• 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
  5 KB (805 words) - 19:06, 27 January 2022
• 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
  4 KB (480 words) - 16:22, 3 February 2022
• 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.
  6 KB (932 words) - 20:24, 25 January 2022
• 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
  3 KB (422 words) - 22:05, 14 February 2022
• 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.
  4 KB (482 words) - 21:00, 31 January 2022
• Normal hydrostatic pressure
  ...rticle, where the fluid state (liquid or gaseous) is important, the state (or phase) is specified.
  3 KB (480 words) - 13:47, 16 February 2022
• Energy Minerals Division
  ...helping to organize or support local society meetings, regional, national or international meetings, symposia, workshops, short courses, and field trips
  2 KB (294 words) - 23:39, 19 January 2021
• 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.
  6 KB (854 words) - 16:19, 20 January 2022
• 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==
  9 KB (1,351 words) - 13:31, 5 April 2022
• Meteoric diagenesis
  Meteoric [[diagenesis]] is the modification of deposits at or near the surface in the [[phreatic]] and [[vadose]] zones.<ref name=Scholle
  648 bytes (87 words) - 15:34, 10 December 2015
• 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
  4 KB (528 words) - 17:48, 24 March 2022
• 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)
  5 KB (658 words) - 22:04, 17 February 2022
• Carbonate
  ...and XF methods|X-Ray Diffractometry]]. Carbonates more rich in calcite and/or aragonite are called [[limestone]]. Carbonate rocks composed mainly of the
  708 bytes (95 words) - 20:42, 7 July 2016
• 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]].)
  3 KB (422 words) - 18:50, 3 February 2022
• 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
  4 KB (618 words) - 19:55, 27 January 2022
• 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
  3 KB (488 words) - 16:13, 31 March 2022
• 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.
  4 KB (601 words) - 22:27, 17 February 2022
• 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.
  6 KB (785 words) - 20:58, 31 January 2022
• 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''.
  5 KB (723 words) - 17:02, 12 April 2022
• Cracking
  ...molecules break apart into smaller molecules during burial [[maturation]] or in a refinery. [[Kerogen]] in source rocks and oil in reservoirs are cracke
  768 bytes (107 words) - 15:14, 23 August 2016
• 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
  3 KB (440 words) - 17:58, 17 February 2022
• Microbial gas
  Also called marsh gas or biogenic gas; typically greater than 99% [[methane]] produced by methanogen
  785 bytes (108 words) - 20:01, 25 June 2015
• 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
  6 KB (794 words) - 20:06, 2 February 2022
• 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
  6 KB (862 words) - 15:20, 4 February 2022
• Evaporite
  ...re minerals produced by the evaporation of water. This may occur in marine or nonmarine settings. The common evaporite minerals associated with petroleum
  1 KB (143 words) - 18:48, 3 March 2016
• 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
  6 KB (811 words) - 17:58, 17 February 2022
• 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
  5 KB (626 words) - 15:18, 31 January 2022
• Tectonic inversion
  ...normal [[fault]]s are reactivated by [[compression]] (positive inversion), or where reverse faults are reactivated by [[extension]] (negative inversion).
  771 bytes (103 words) - 20:25, 6 July 2015
• 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.
  10 KB (1,231 words) - 20:28, 4 January 2024
• 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
  5 KB (617 words) - 19:55, 27 January 2022
• 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
  8 KB (1,156 words) - 21:19, 19 January 2022
• 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.
  6 KB (882 words) - 17:19, 6 April 2022
• 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).
  10 KB (1,468 words) - 18:23, 21 January 2022
• 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
  3 KB (427 words) - 16:16, 5 April 2022
• Governance
  * Avoid complexity or obscurity
  718 bytes (103 words) - 15:23, 6 August 2013
• 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
  3 KB (430 words) - 15:35, 1 February 2022
• 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
  8 KB (1,128 words) - 22:24, 31 January 2022
• 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
  2 KB (296 words) - 17:35, 13 April 2022
• 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
  5 KB (784 words) - 15:28, 15 February 2022
• Activation energy
  ...for chemical transformations, commonly expressed in kilocalories per mole or kilojoules per mole. Activation energy distributions are used in [[maturati
  781 bytes (109 words) - 15:13, 23 August 2016
• 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.
  10 KB (1,352 words) - 19:07, 6 April 2022
• 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
  825 bytes (118 words) - 20:13, 14 March 2016
• AAPG Wiki:Terms of use
  ...any changes to articles, and has full scientific authority over acceptance or rejection of alterations and deletions.
  848 bytes (125 words) - 16:58, 9 October 2013
• 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
  3 KB (498 words) - 16:03, 18 February 2022
• 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
  5 KB (619 words) - 22:26, 3 February 2022
• 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
  4 KB (556 words) - 22:10, 7 January 2015
• 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
  8 KB (1,207 words) - 16:33, 13 April 2022
• 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
  4 KB (562 words) - 19:42, 27 January 2022
• 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
  3 KB (474 words) - 18:22, 21 January 2022
• 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.
  7 KB (1,100 words) - 21:16, 19 January 2022
• 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
  7 KB (969 words) - 19:14, 25 January 2022
• 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
  5 KB (673 words) - 15:16, 31 January 2022
• 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
  6 KB (828 words) - 16:32, 4 April 2022
• 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.
  3 KB (486 words) - 17:53, 25 January 2022
• 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
  941 bytes (133 words) - 19:55, 25 June 2015
• Unconformity
  ...record of geological time, during which deposition had ceased and folding or faulting occurred, the lower strata tilted, and then deposition resumed.]]
  1 KB (158 words) - 14:47, 24 March 2015
• 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
  6 KB (997 words) - 17:55, 17 February 2022
• 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
  5 KB (708 words) - 21:00, 6 April 2022
• 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
  2 KB (354 words) - 22:07, 1 February 2022
• 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
  7 KB (894 words) - 14:15, 11 April 2022
• 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
  9 KB (1,366 words) - 16:37, 19 January 2022
• 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.
  7 KB (1,083 words) - 20:50, 19 January 2022
• 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
  6 KB (850 words) - 17:22, 4 April 2022
• 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
  5 KB (687 words) - 17:09, 5 April 2022
• 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''.
  9 KB (1,404 words) - 21:17, 19 January 2022
• 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
  9 KB (1,348 words) - 15:55, 6 August 2013
• Carbonate facies
  ==Platform or ramp development==
  3 KB (433 words) - 18:32, 6 April 2022
• 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.,
  3 KB (449 words) - 18:12, 31 January 2022
• 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
  8 KB (1,127 words) - 20:21, 23 January 2019
• 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:
  4 KB (598 words) - 19:47, 24 March 2022
• 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:
  4 KB (572 words) - 17:56, 17 February 2022
• Structural fairway prospectivity
  Certain [[structural domains]] or specific portions of those domains provide the greatest opportunities for e * Tectonic [[overburden]] or denudation
  3 KB (340 words) - 18:50, 3 February 2022
• 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.
  13 KB (1,979 words) - 19:26, 19 January 2022
• 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
  5 KB (785 words) - 17:04, 29 March 2022
• 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.
  4 KB (483 words) - 15:15, 31 January 2022

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