Changes

===Conformity===

===Conformity===

A technique used to model conformable surfaces is thickness addition or subtraction. It is used because directly gridding each surface in a group of conformable surfaces may not produce the best results. Often variations in data distributions allow one surface to project past another or to have significantly more form definition than others of that sequence (Figure 6). The conformable technique builds a grid for the surface with the best data distribution (control surface) within a sequence of conformable surfaces and then adds or subtracts the adjacent interval's thickness to generate conformable surfaces above or below it. The newly constructed structural surface now becomes the surface to which thickness is added or subtracted to produce the next higher or lower surface. The process continues upward and downward until all surfaces within the sequence are constructed (Figure 7). This approach works well for complete data sets and vertical wells, although additional steps are required to handle deviated wells, partial penetrations, or missing data<ref name=pt08r11 />.

[[file:using-and-improving-surface-models-built-by-computer_fig6.png|thumb|{{figure number|6}}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.]]

[[file:using-and-improving-surface-models-built-by-computer_fig6.png|thumb|{{figure number|6}}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.]]

A technique used to model conformable surfaces is thickness addition or subtraction. It is used because directly gridding each surface in a group of conformable surfaces may not produce the best results. Often variations in data distributions allow one surface to project past another or to have significantly more form definition than others of that sequence ([[:file:using-and-improving-surface-models-built-by-computer_fig6.png|Figure 6]]). The conformable technique builds a grid for the surface with the best data distribution (control surface) within a sequence of conformable surfaces and then adds or subtracts the adjacent interval's thickness to generate conformable surfaces above or below it. The newly constructed structural surface now becomes the surface to which thickness is added or subtracted to produce the next higher or lower surface. The process continues upward and downward until all surfaces within the sequence are constructed ([[:file:using-and-improving-surface-models-built-by-computer_fig7.png|Figure 7]]). This approach works well for complete data sets and vertical wells, although additional steps are required to handle deviated wells, partial penetrations, or missing data<ref name=pt08r11 />.

[[file:using-and-improving-surface-models-built-by-computer_fig7.png|thumb|{{figure number|7}}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.]]

[[file:using-and-improving-surface-models-built-by-computer_fig7.png|thumb|left|{{figure number|7}}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.]]

The conformable technique is often used to transfer the shape of an existing surface to a new surface while honoring the data of that new surface. Common applications include stream channels and the top of draping rock units<ref name=pt08r9>Hamilton, D. E., Jones, T. A., eds., 1992, Computer Modeling of Geologic Surfaces and Volumes: AAPG Computer Applications in Geology, n. 1, 297 p.</ref>.

The conformable technique is often used to transfer the shape of an existing surface to a new surface while honoring the data of that new surface. Common applications include stream channels and the top of draping rock units<ref name=pt08r9>Hamilton, D. E., Jones, T. A., eds., 1992, Computer Modeling of Geologic Surfaces and Volumes: AAPG Computer Applications in Geology, n. 1, 297 p.</ref>.