Search results

• Interval transit time
  This is the inverse of velocity and is what is displayed on a sonic log, usually in units of μs/ft or μs
  205 bytes (40 words) - 20:03, 14 April 2014
• Seismic data: building a stratigraphic model
  ...generated where there is a contrast in impedance (which is the product of velocity and density). ==Velocity data sources==
  5 KB (805 words) - 19:06, 27 January 2022
• Seismic data - creating an integrated structure map
  ...er such as glacial till). It also fails when there are extreme [[lateral]] velocity variations in the subsurface (subsalt, subthrust, etc.). When it works, thi # Calculate depth conversion velocity at locations where both well and seismic time picks exist.
  7 KB (1,117 words) - 17:51, 25 January 2022
• Synthetic seismograms: correlation to other data
  ...away from the vertical. If anisotropy is present (and it usually is), then velocity depends on the direction the wave is traveling. It is not uncommon to see a
  3 KB (486 words) - 19:10, 27 January 2022
• Pressure prediction: analysis of well-log and seismic data
  ==Seismic velocity== ...dicate an undercompacted (overpressured) interval. Unusually fast interval velocity, conversely, may indicate overcompaction (underpressure).
  5 KB (733 words) - 17:57, 17 February 2022
• Seismic data and mapping structure
  | Classic || Mapping a surface of interest (from data) using [[Average velocity|average velocities]] ...a (with time axis) converted to a depth cube using a ''V'' ( ''X, Y, Z'' ) velocity model
  2 KB (320 words) - 19:10, 27 January 2022
• Seismic data: identifying reflectors
  ...fig12-8.png|300px|thumb|{{figure number|1}}Sonic log converted to time and velocity. From Liner;<ref name=Liner1999>Liner, C., 1999, Elements of 3-D Seismology ...a [[Basic open hole tools#Sonic|sonic]] log has been converted to time and velocity. Note that the time axis on the seismic section and the converted sonic log
  2 KB (348 words) - 19:10, 27 January 2022
• Seismic data preparation for mapping
  # Identify online wells with velocity control. ...oints. Whatever the method, it should also be used in the depth conversion velocity map (next section). The wells-only depth structure map is a useful baseline
  7 KB (1,064 words) - 19:11, 27 January 2022
• Full waveform acoustic logging
  ...about the lithology and the fluid content of the formation. Stoneley wave velocity and amplitude have been shown to be useful in the detection of fractures an ...hat is slower than both the formation shear wave velocity and the acoustic velocity of the borehole fluid.
  10 KB (1,530 words) - 20:47, 19 January 2022
• Seismic facies analysis
  * [http://wiki.seg.org/wiki/Dictionary:Interval_velocity Interval velocity] * Velocity and density contrasts of individual interfaces
  6 KB (809 words) - 17:46, 4 February 2022
• Seismic data - mapping with two-dimensional data
  ...teral differences in velocity on conversion of time and depth. If a single velocity function of 8300 ft/sec were used, errors of +6 ft at A and -440 ft at B wo mapping-with-two-dimensional-seismic-data_fig5.png|{{figure number|5}}Velocity map with velocities marked at grid intersections.
  13 KB (1,936 words) - 21:29, 21 January 2022
• Magnetotellurics case history: Precambrian overthrust (Northwestern Colorado)
  ...where high-velocity (high-resistivity, low-conductivity) rocks overlie low-velocity (low-resistivity, high-conductivity) sediments.
  3 KB (383 words) - 15:13, 31 January 2022
• 3-D seismic data: immersive visualization
  ==Calculating depth conversion velocity==
  4 KB (601 words) - 19:49, 27 January 2022
• Seismic inversion
  ...rth reflections as a function of time to the geologist's view of the earth velocity as a function of depth. This is not as easy as it may seem. The reason for ...ide, we introduce geological constraints taken from a sonic log or seismic velocity information and produce a forward model. We then combine the information fr
  8 KB (1,196 words) - 18:48, 21 January 2022
• Checkshots and vertical seismic profiles
  ...daries of these units need to be mapped in depth. Thus, the concept of the velocity checkshot survey has been developed to establish time-depth calibration fun ...s measured.<ref name=pt07r1>Anstey, N. A., and R. L. Geyer, 1987, Borehole velocity measurements and the synthetic seismogram: Boston, MA, IHRDC, 355 p.</ref>
  11 KB (1,599 words) - 20:48, 19 January 2022
• Seismic migration
  ...ey conducted over a subsurface medium that is homogeneous (constant P-wave velocity) with the exception of an isolated boulder at some depth. Also shown are th ...for a subsurface consisting of a single dipping reflector. For a constant-velocity subsurface, the many weak diffractions from very closely spaced points alon
  14 KB (2,045 words) - 20:21, 21 January 2022
• Vertical and lateral seismic resolution and attenuation
  ...ocity and a 15-Hz wavelet. Resolution decreases rapidly with depth because velocity increases and frequency decreases. ...contributing to limit the horizontal resolution include uncertainty in the velocity and the mathematical completeness of the migration algorithm. One of the mo
  8 KB (1,164 words) - 20:24, 21 January 2022
• Seismic data display
  ...ks were reversed (that is, travel is from a high velocity rock to a slower velocity rock), the coefficient of reflection is said to be ''negative'' and is disp ...raphic sequences. A display of a variation in amplitude, phase, frequency, velocity, or any other trace-related attribute can be represented by different color
  9 KB (1,404 words) - 21:17, 19 January 2022
• Cross-borehole tomography
  ...presented by a color-coded map in which a color is assigned to the seismic velocity at each point. This map, or plot, is referred to as a ''tomogram''. Other d ...2.png|Figure 2]]. These traveltime data are then used to infer the seismic velocity field between the wellbores. If attenuation measurements can be made on the
  14 KB (2,060 words) - 20:51, 19 January 2022
• Amplitude (seismic)
  : <math>\text{IA} = \text{Density} \times \text{Velocity}</math> ...sure and pore pressure. The relationship between gas saturation and P wave velocity drops drastically resulting in the formation of anomalies such as DHI, AVO,
  8 KB (1,291 words) - 15:49, 18 January 2017
• Seismic data interpretation - recurring themes
  ...seismic, plus [[Seismic array|arrays]], [[offset]], [[dip]], and [[lateral velocity]] variation. The next layer, 3-D seismic, includes all of 2-D plus [[azimut ...smic analysis is, in effect, an edge detection technique. The bigger the [[velocity]] and/or [[density]] contrast between the rocks, the stronger the edge.
  5 KB (739 words) - 18:51, 27 January 2022
• Lwandle plate
  ...d the [[African Plate|Nubian Plate]]. Its discovery is very recent, so the velocity of the plate isn't well known or understood.<ref name=Saria>Saria, E., 2014 ...iors.<ref name=Nocquet&Calais>Nocquet, J.-M., and E. Calais, 2003, Crustal velocity field of western Europe from permanent GPS array solutions, 1996-2001: Geop
  10 KB (1,574 words) - 16:51, 6 April 2016
• Synthetic seismogram
  Velocity data from the sonic log (and the [[density log]], if available) are used to * ''υ'' = rock velocity
  8 KB (1,199 words) - 13:57, 24 January 2022
• Rock physics analysis for reservoir identification
  ...wever, the Vs does not affected much and therefore will produce low Vp/Vs. Velocity ratio is mathematically defined as follow: <p><math>V_p/V_s = \frac{V_p}{V_ ...upper layer, whereas AI2, Vp2, and Rho2 are the acoustic impedance, P-wave velocity, and density of the lower layer. On [[:File:GeoWikiWriteOff2021-Muamamr-Fig
  15 KB (2,356 words) - 18:00, 26 April 2022
• Wellsite math
  | AV || Annular velocity || ft/min | JNV || Jet nozzle velocity || ft/sec
  21 KB (3,142 words) - 15:10, 24 January 2022
• Seismic attributes
  ...arity]], [[phase]], [[Seismic frequency|frequency]], or [[Seismic velocity|velocity]]. [[Horizon attribute]]s were first used in the mid-1980s for interpreting
  6 KB (859 words) - 19:42, 27 January 2022
• Rock-water reaction
  # [[Injection]] or production of fluids at rates exceeding the critical velocity beyond which mobilization of rock fines by mechanical (drag) forces is init ...e conducted at rates below the critical velocity. Conversely, the critical velocity will vary depending on whether fluids are chemically compatible with the ro
  17 KB (2,356 words) - 19:24, 19 January 2022
• Rock-water reaction: formation damage
  * Injection or production of fluids at rates exceeding the critical velocity beyond which mobilization of rock fines by mechanical (drag) forces is init ...e conducted at rates below the critical velocity. Conversely, the critical velocity will vary depending on whether fluids are chemically compatible with the ro
  17 KB (2,380 words) - 18:23, 21 January 2022
• Amplitude variations with offset (AVO)
  ...ons will be the difference of acoustic impedance (product of density and P velocity) over the sum. ...ludes the first P wave velocity, the second node density and the last wave velocity.
  9 KB (1,404 words) - 21:39, 27 March 2019
• Condensate banking effect
  ...number|5}}Condensate saturation versus radial distance from wellbore, with velocity stripping zone.<ref name=Daungkaewandgringarten_2004 /> ...e in gas mobility is observed at higher velocities, and thus is termed the velocity stripping effect, which can increase the productivity of a well. This can f
  21 KB (3,040 words) - 15:22, 12 December 2022
• Magnetotelluric survey case history: volcanic terrain (Columbia River Plateau)
  ...spersive nature of the volcanics and because of the decrease in [[acoustic velocity]] at the base of the volcanics.
  3 KB (359 words) - 15:15, 31 January 2022
• Seismic processing basics
  ...dual statics are all techniques used to estimate and apply the appropriate velocity and time corrections ([[:file:basic-seismic-processing_fig5-part1.jpg|Figur ===f–k or apparent velocity filter===
  19 KB (2,895 words) - 20:23, 21 January 2022
• Open hole tools
  | Sonic || 2 ft || Typically 6 in. || Measure compressional velocity and estimate porosity || Sensitive to compressibility ...timate porosity || Cannot measure shear velocity when shear velocity > mud velocity
  23 KB (3,350 words) - 17:26, 18 January 2022
• Well log analysis for reservoir characterization
  ...lity, etc.) which are more geology-like and rock physics (elasticity, wave velocity, etc.) which are more geophysics-like. Every properties are related each ot ...alculate clay volume, permeability calculation, porosity calculation, wave velocity calculation, etc.
  25 KB (3,679 words) - 21:17, 13 March 2019
• Seismic interpretation
  ...rface. The actual depth to this surface is a function of the thickness and velocity of overlying rock layers. The second is the shape of the reflection, which ...ages is made, including ''p'' wave seismic, shear wave seismic, well data, velocity surveys, and VSP. The data are scanned for quality and suitability. At this
  10 KB (1,520 words) - 18:48, 21 January 2022
• Forward modeling of seismic data
  ...ght is tight. [[Porosity]] is represented in the model by a lower interval velocity and lower density than the surrounding rock (see [[Porosity]]). ...The porosity is identified by the dim spot on traces 6 through 11 and the velocity pulldown of the underlying event. The results from this modeling indicate t
  10 KB (1,513 words) - 21:16, 19 January 2022
• Pressure detection
  ...eases with depth. If the shales have not been able to compact, the seismic velocity will be less. ...rface by the common depth point method of seismic acquisition. If interval velocity increases normally with depth and then decreases, it is possible that a zon
  16 KB (2,450 words) - 21:42, 20 January 2022
• Production logging
  production-logging_fig3.png|{{figure number|3}}Tracer velocity shot technique and injection profile. ...surface recordings are shown to the right of the well sketch. The highest velocity and flow rate are recorded above the perforations, while zero flow is detec
  12 KB (1,726 words) - 16:48, 20 January 2022
• Production problems
  ...ts near the wellbore. Fluid flow within the pores may also reach turbulent velocity, thus generating additional pressure drop and reducing the productivity of ...an also accumulate in the wellbore if the gas is not flowing at sufficient velocity to lift the water from the well. Accumulation of this static fluid column c
  16 KB (2,540 words) - 18:41, 20 January 2022
• Structural lead and prospect delineation
  * Special seismic processing and velocity analysis (e.g., prestack migration; amplitude vs. [[offset]])
  4 KB (511 words) - 18:50, 3 February 2022
• Gravity data processing
  | Platform's velocity & heading
  4 KB (519 words) - 14:16, 31 January 2022
• Amplitude versus offset (AVO) analysis
  ...ng requires the following: (1) a depth-[[velocity]] model, (2) density and velocity trend curves, (3) [[porosity]] ranges, (4) fluid content variation, (5) Poi ...as the starting point for the inversion process, the final [[compressional velocity]], [[density]], and [http://en.wikipedia.org/wiki/Poisson%27s_ratio Poisson
  12 KB (1,723 words) - 18:41, 20 January 2022
• Two-dimensional geophysical workstation interpretation: generic problems and solutions
  **Velocity information ...a correction time is added or subtracted to each profile and a correction velocity is applied to the profile. During interpretation, corrections dealing with
  20 KB (2,848 words) - 14:29, 20 January 2022
• Molyneux:sandbox
  * [[Velocity]] This is on the [[Seismic attributes]] page
  5 KB (543 words) - 23:45, 8 January 2015
• Shale tectonics
  ...e range of 6500–8500 ft/s (1981.2–2590.8 m/s) with very little increase in velocity with depth; (2) low density, estimated to be in the range of 2.1–2.3 g/cm * Shales have a much slower velocity than salt. Salt will be underlain by seismic pull-up versus no pull-up bene
  17 KB (2,466 words) - 16:16, 10 January 2024
• Petroleum exploration
  ...ace, uphole survey is conducted to find the thickness and velocity of low- velocity layer; which will be followed by seismic refraction. ...d obtain imagery of the subsurface. The process include noise attenuation, velocity analysis, deconvolution, migration, stacking, and so on. Once the data have
  15 KB (2,331 words) - 19:12, 17 April 2019
• Using conventional well logs to estimate richness
  ...n a rock directly affects its properties by lowering density slowing sonic velocity increasing radioactivity raising resistivity and raising hydrogen and carbo
  5 KB (768 words) - 15:48, 9 February 2022
• Geological fieldwork benefits
  ...zed for age, [[Total organic carbon (TOC)|organic richness]], and acoustic velocity can advance the understanding of basin history, the [[source rock]] [[Litho
  5 KB (771 words) - 21:12, 1 February 2022
• Relationship between porosity and permeability on fractured basement reservoir
  ...tic. In high velocity, water washes oil completely from matrix, but in low velocity where capillary pressure become significant, oil stuck in the porous. So fr ...y Abgrall dan Iffly, 1973, shows that gas saturation can be very high when velocity decrease very slowly. Gas phase in porous without move from porous until mo
  29 KB (4,601 words) - 16:09, 12 April 2016
• Karst topography
  ...whether karstification can develop or not and simulation factors determine velocity and completeness of the karstification proces.s The velocity of reaction so true as bigger in low temperature, because concentration of
  13 KB (2,016 words) - 19:56, 5 April 2019

View (previous 50 | next 50) (20 | 50 | 100 | 250 | 500)