General Setting
Information Search and Selection

Com ments

on

Geo logic

Para meters

1 Depth:

2 Permeability/Hydraulic Conductivity:

3 Formation Thickness:
4 Net Sand Thickness:
5 Percent Shale:
6 Continuity:
7 Top Seal Thickness:
8 Continuity of top seal:
9 Hydrocarbon Production:
10 Fluid Residence Time:
11 Flow Direction Elevation:

12

CO2 Solu bility Brine

 12a Temperature:
12b Pressure:
12c Salinity:
13 Rock/Water Reaction:
14 Porosity:
15 Water Chemistry:
16 Rock Mineralogy:

Fox Hills — Lower Hell Creek, Powder River Basin

Comments on Geologic Parameters

7 Top Seal Thickness:

The Fox Hills Sandstone has a regionally extensive top seal known as the Upper Hell Creek Confining Layer. The thickness of this top seal is well documented across the entire Powder River Basin (Lewis and Hotchkiss, 1981). The thickness of the top seal increases from approximately 200 ft (61 m) in Montana to more than 1,000 ft (>304.9 m) in the south part of the basin, where distal-shoreface and shelf Fox Hills Sandstones intertongue and are overlain by marine mudstones in the Lewis Shale.

7 Map:

7 Reference:

Lewis, B. D., and Hotchkiss, W. R., 1981, Thickness, percent sand, and configuration of shallow hydrogeologic units in the Powder River Basin, Montana and Wyoming: U. S. Geological Survey, Miscellaneous Investigations Series, Map I-1317, 6 sheets.