Changes

==Prospect and location==

==Prospect and location==

<gallery mode=packed widths=200px heights=200px>

<gallery mode=packed widths=200px heights=200px>

file:exploring-for-structural-traps_fig20-14.png|{{figure number|11}}See text for explanation.

file:exploring-for-structural-traps_fig20-14.png|{{figure number|11}}Photograph showing structures in the upper plate of the Absaroka thrust fault.

file:exploring-for-structural-traps_fig20-15.png|{{figure number|12}}From <ref name=Lamerson_1982 />; courtesy Rocky Mountain Association of Geologists.

file:exploring-for-structural-traps_fig20-15.png|{{figure number|12}}Example of detailed structural mapping at the prospect level. From Lamerson;<ref name=Lamerson_1982 /> courtesy Rocky Mountain Association of Geologists.

file:exploring-for-structural-traps_fig20-16.jpg|{{figure number|13}}Published with permission of James Morse, Computational Geology.

file:exploring-for-structural-traps_fig20-16.jpg|{{figure number|13}}Physical models display structures similar in shape to natural, prospect-scale, thrust-related structures can provide insight on the overall geometry of the prospect and the location of zones of high strain (high fracture density?) within the structure. Published with permission of James Morse, Computational Geology.

file:exploring-for-structural-traps_fig20-17.png|{{figure number|14}}See text for explanation.

file:exploring-for-structural-traps_fig20-17.png|{{figure number|14}}Examples of outcrop fracture-spacing data relevant to the carbonate section of Whitney Canyon field

file:exploring-for-structural-traps_fig20-18.png|{{figure number|15}}From Nelson and Serra<ref name=Nelsonandserra_1995>Nelson, R. A., and S. Serra, 1995, Vertical and lateral changes in fracture spacing in several folded carbonate sections and its relation to locating horizontal wells: Journal of Canadian Petroleum Technology, v. 34, p. 51-56.</ref>; courtesy Journal of Canadian Petroleum Technology.

file:exploring-for-structural-traps_fig20-18.png|{{figure number|15}}Outcrop sketch of folds in the Devonian Darby siltstone and Ordovician Bighorn dolomite. From Nelson and Serra<ref name=Nelsonandserra_1995>Nelson, R. A., and S. Serra, 1995, Vertical and lateral changes in fracture spacing in several folded carbonate sections and its relation to locating horizontal wells: Journal of Canadian Petroleum Technology, v. 34, p. 51-56.</ref>; courtesy Journal of Canadian Petroleum Technology.

</gallery>

</gallery>

Data on deformation mechanisms, such as fractures and how they affect reservoir properties, are obtained by integrating outcrop fracture data and laboratory estimates of fracture aperture. This integration allows for a direct calculation of fracture [[porosity]] and fracture [[permeability]] for the reservoir.

Data on deformation mechanisms, such as fractures and how they affect reservoir properties, are obtained by integrating outcrop fracture data and laboratory estimates of fracture aperture. This integration allows for a direct calculation of fracture [[porosity]] and fracture [[permeability]] for the reservoir.

Examples of outcrop fracture-spacing data relevant to the carbonate section of Whitney Canyon field are shown in [[:file:exploring-for-structural-traps_fig20-14.png|Figure 13]]. The photograph shows fractures in the Ordovician Bighorn dolomite in outcrops in the valley seen in [[:file:exploring-for-structural-traps_fig20-14.png|Figure 11]]. (Note the inch-scale measuring tape stretched across the center of [[:file:exploring-for-structural-traps_fig20-17.png|Figure 14]].)

Examples of outcrop fracture-spacing data relevant to the carbonate section of Whitney Canyon field are shown in [[:file:exploring-for-structural-traps_fig20-17.png|Figure 14]]. The photograph shows fractures in the Ordovician Bighorn dolomite in outcrops in the valley seen in [[:file:exploring-for-structural-traps_fig20-14.png|Figure 11]]. (Note the inch-scale measuring tape stretched across the center of [[:file:exploring-for-structural-traps_fig20-17.png|Figure 14]].)

The outcrop sketch in [[:file:exploring-for-structural-traps_fig20-18.png|Figure 15]] is of folds in the Devonian Darby siltstone and Ordovician Bighorn dolomite from the same location as [[:file:exploring-for-structural-traps_fig20-17.png|Figure 14]]. The numbers on the sketch represent fracture intensity values expressed as the average number of fractures encountered per foot of scanline measurement at various locations on the folds. All else being equal, higher fracture intensities should be associated with zones of higher fracture porosities and permeabilities. Maps of high fracture intensities can be used to locate optimum well locations and well trajectories in prospects.

The outcrop sketch in [[:file:exploring-for-structural-traps_fig20-18.png|Figure 15]] is of folds in the Devonian Darby siltstone and Ordovician Bighorn dolomite from the same location as [[:file:exploring-for-structural-traps_fig20-17.png|Figure 14]]. The numbers on the sketch represent fracture intensity values expressed as the average number of fractures encountered per foot of scanline measurement at various locations on the folds. All else being equal, higher fracture intensities should be associated with zones of higher fracture porosities and permeabilities. Maps of high fracture intensities can be used to locate optimum well locations and well trajectories in prospects.