User contributions
13 January 2014
File:Using-and-improving-surface-models-built-by-computer fig23.png
The envelope technique is used to define one grid for the top of reservoir and another for the base of the reservoir. These are subtracted to create the gross hydrocarbon rock thickness. Category:Integrated computer methods
File:Using-and-improving-surface-models-built-by-computer fig22.png
The gross hydrocarbon rock thickness is progressively reduced by net to gross ratio, average porosity, and oil saturation, until only the thickness of pores filled with hydrocarbon remains. Category:Integrated computer methods
File:Using-and-improving-surface-models-built-by-computer fig21.png
Thickness Is normally defined by grids representing the top and base of reservoir and the fluid contact(s). Category:Integrated computer methods
File:Using-and-improving-surface-models-built-by-computer fig20.png
A mathematical surface is fit to the grid cell. Calculus is used to integrate the volume under the curve, inside the grid cell, and inside the polygon. All cell volumes inside the polygon are added together. Category:Integrated computer methods
File:Using-and-improving-surface-models-built-by-computer fig19.png
The cell's corners are defined by grid nodes. The top is defined by two or more planes passing through the node z values and lie inside the polygon. The prism of volume under each plane is calculated and added to volumes for all other prisms inside the...
File:Using-and-improving-surface-models-built-by-computer fig18.png
The cell is centered on the grid node and lies either inside or outside the polygon. The cell's area is multiplied by its z value (thickness) and that volume is added to volumes for all other cells inside the polygon. [[Category:Integrated computer me...
File:Using-and-improving-surface-models-built-by-computer fig17.png
The data value is adjusted by the separation of faults crossed by the line connecting the data point and the location for which an estimate is being made. Category:Integrated computer methods
File:Using-and-improving-surface-models-built-by-computer fig16.png
(a) Surface model built with no fault constraints. (b) Model of vertical separation. (c) Unfaulted structure model built after removing vertical separation from data. (d) Faulted structure model built by subtracting separation model from unfaulted stru...
File:Using-and-improving-surface-models-built-by-computer fig15.png
Faults act as barriers beyond which data cannot be seen from the location for which a surface value is being calculated. (a) A grid node (indicated by +) to the west of fault A can only see data in the hatchured area. (b) A grid node farther to the sou...
File:Using-and-improving-surface-models-built-by-computer fig14.png
Surface models are constructed for the faults and for each surface on each side of each fault. Operations between surface models prevent them from projecting past one another. Category:Integrated computer methods
File:Using-and-improving-surface-models-built-by-computer fig13.png
Separate surface models are built for each fault block. (a, b, and c) The surface for each fault block is allowed to extend past faults defining the block edge. (d) When displayed, contours are constrained to inside the fault block polygon and all mode...
File:Using-and-improving-surface-models-built-by-computer fig12.png
The middle surface baselaps onto the lower surface and is truncated by the higher surface. (a) Cross section showing proper relationships. (b) Map showing surface contours and lines of baselap and truncation. Category:Integrated computer methods
File:Using-and-improving-surface-models-built-by-computer fig11.png
Map showing contours and subcrop lines. Category:Integrated computer methods
File:Using-and-improving-surface-models-built-by-computer fig10.png
Cross section showing surfaces before baselap operations. The zero contour of the model built by subtracting the two surfaces defines the subcrop line. Category:Integrated computer methods
File:Using-and-improving-surface-models-built-by-computer fig9.png
Cross sections showing a baselapping surface (a) as coincident with the lower surface in areas of baselap (for cross section display) and (b) as missing in areas of baselap (for map display). Category:Integrated computer methods
File:Using-and-improving-surface-models-built-by-computer fig8.png
Cross sections showing that surfaces that intersect due to (a) baselap or (b) truncation will incorrectly cross one another. Category:Integrated computer methods
File:Using-and-improving-surface-models-built-by-computer fig7.png
Cross section showing four conformable surfaces. The second from the top is the control and is modeled using structure data. The other surfaces are built using the conformable method. Category:Integrated computer methods
File:Using-and-improving-surface-models-built-by-computer fig6.png
Cross section showing two conformable surfaces. Dashed line represents direct modeling of lower surface data. Solid lines represent direct modeling of upper surface data and conformable modeling of lower surface data. [[Category:Integrated computer me...
File:Using-and-improving-surface-models-built-by-computer fig5.png
Contour maps of the same data. (a) Most algorithms weight data isotropically and creat circular surface forms. (b) Single direction bias forces elliptical weighting, allowing surface form to stretch in one direction. [[Category:Integrated computer met...
File:Using-and-improving-surface-models-built-by-computer fig4.png
Cross sections through the same data. (a) The surface model does not honor the data. (b) Surface is shifted to data by modeling the error between the data and the original surface and then adding the original and error models. [[Category:Integrated co...
File:Using-and-improving-surface-models-built-by-computer fig3.png
Cross sections through the same data. (a) Extrapolated values for a weighted average algorithm tend to “come back” to the average of near data values. (b) Acceptable surface extrapolation achieved by creating a first-order trend, modeling residuals...
File:Using-and-improving-surface-models-built-by-computer fig2.png
Cross section showing the output from filtering being constrained between models built by shifting the initial surface model up and down slightly. Category:Integrated computer methods
File:Using-and-improving-surface-models-built-by-computer fig1.png
Contour maps of the same surface data. (a) Unconstrained extrapolation into nondata areas. (b) Contours constrained to areas near data. Category:Integrated computer methods
Using and improving surface models built by computer
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File:Introduction-to-contouring-geological-data-with-a-computer fig6.png
A13 × 13 grid showing the relationship between grid nodes and control points for the Davis (1973) data set. Category:Integrated computer methods
File:Introduction-to-contouring-geological-data-with-a-computer fig7.png
A representation of the fourth-order polynomial of Figure 4 contoured on a grid prepared using a nearest neighbor search criterion. Category:Integrated computer methods
File:Introduction-to-contouring-geological-data-with-a-computer fig5.png
Contours from a 13 × 13 grid using nearest neighbor search. (Data from Davis, 1973.) Category:Integrated computer methods
File:Introduction-to-contouring-geological-data-with-a-computer fig4.png
Surface contoured on a triangular mesh. The original surface is a fourth-order polynomial. Category:Integrated computer methods
File:Introduction-to-contouring-geological-data-with-a-computer fig3.png
Contoured triangular mesh of Figure 2. Category:Integrated computer methods
File:Introduction-to-contouring-geological-data-with-a-computer fig2.png
Triangular mesh prepared from Davis (1973) data. Category:Integrated computer methods
File:Introduction-to-contouring-geological-data-with-a-computer fig1.png
(a) Random points. (b) Clustered points. Category:Integrated computer methods
Contouring geological data with a computer
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File:Evaluating-stratigraphically-complex-fields fig1.png
Example of electrofacies map showing distribution of SP log patterns. (From Galloway and Cheng, 1985.) Category:Geological methods
Stratigraphically complex fields
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Cash flow model
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+5,655
Lithofacies and environmental analysis of clastic depositional systems
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-477
File:Lithofacies-and-environmental-analysis-of-clastic-depositional-systems fig3.png
Models of major depositional environments. The curve on the left shows the SP or gamma ray response and the curve on the right shows the relative grain size profile. The size of the dots next to the vertical profile indicates the relative magnitude of ...
File:Lithofacies-and-environmental-analysis-of-clastic-depositional-systems fig2.png
Gamma ray correlation (dip section) of a series of prograding shoreface sandstones. Note the imbricate nature of the sandstone bodies and the “non-layer cake” nature of the correlations. Category:Geological methods
File:Lithofacies-and-environmental-analysis-of-clastic-depositional-systems fig1.png
Sedimentary processes, lithofacies, and lithofacies associations for a meandering channel sequence. (The vertical sequence is modified from Walker and Cant, 1984.) Category:Geological methods
Lithofacies and environmental analysis of clastic depositional systems
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Checkshots and vertical seismic profiles
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-1
File:Checkshots-and-vertical-seismic-profiles fig4.png
Examples of the source-receiver positions involved in (a and b) zero offset and (c and d) offset VSP recording geometries. Category:Geophysical methods
File:Checkshots-and-vertical-seismic-profiles fig3.png
The source position (A or B) should be chosen so that the travel path to each receiver is as nearly vertical as possible. Category:Geophysical methods
File:Checkshots-and-vertical-seismic-profiles fig2.png
The source-receiver geometry commonly used to record checkshots in deviated wells. Category:Geophysical methods
File:Checkshots-and-vertical-seismic-profiles fig1.png
The source-receiver geometry commonly used in onshore checkshot surveys. Category:Geophysical methods
Checkshots and vertical seismic profiles
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Carbonate diagenesis
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+11
File:Carbonate-reservoir-models-facies-diagenesis-and-flow-characterization fig4.png
Schematic diagram of the karst-collapse reservoir model showing three karst facies. (From Kerans, 1989.) Category:Geological methods
File:Carbonate-reservoir-models-facies-diagenesis-and-flow-characterization fig3.png
Schematic diagrams of the upward-shoaling cementation and compaction reservoir model and the subtidat-supratidal dolomitlzation and sulfate emplacement reservoir model. Category:Geological methods
File:Carbonate-reservoir-models-facies-diagenesis-and-flow-characterization fig2.png
Carbonate depositional environments. (Diagram by R. G. Loucks and C. R. Handford, unpublished.) Category:Geological methods