Plays in the Deep Basin area are deep, overpressured, and gas-saturated, offering substantial gas-in-place and regional, stacked resource play potential. However, the transition from the Deep Basin to the Foothills Disturbed Belt is poorly understood. A number of issues stand out for explorers active in this area, including:
- What is the hydrodynamic signature of the Deep Basin to Foothills transition?
- Where does the transition between the Deep Basin and Foothills system occur?
- Is there potential for a resource play in the transition?
- What is the gas/water relationship within Dunvegan, Cadotte, Falher, Cadomin and Nikanassin reservoirs in structural traps in the Grande Cache area?
This study presents hydrogeologic data and interpretations for the interval from the base of the Mannville to the top of the Dunvegan in west-central Alberta. The study area boundaries are Twp. 57-66, Rge. 5-14W6. This study develops a hydrostratigraphic framework for the Deep Basin and defines zones of potentially gas-charged reservoir continuity. The results are presented in drill-stem test (DST) recovery maps and pressure versus elevation graphs. Gas columns and pools in the area were subdivided into three pressure regimes: higher-pressured Deep Basin, lower-pressured Deep Basin, and the possibly conventional Foothills System. The Deep Basin area is defined as a dynamic source rock/reservoir system in which gas is the continuous intergranular phase and water is present, only locally, as discontinuous aquifers. The distinction between the higher and lower-pressured Deep Basin is based on the location of the regional water column on the pressure versus elevation graphs. In the Foothills Regional System, there is some evidence that gas may be discontinuous, and only trapped in conventional structural and stratigraphic traps.