FLUID FLOW IN WESTERN CANADA SEDIMENTARY BASIN .2. EFFECT OF GEOLOGY

The observed effect of variations of geology on the fluid potential distribution is treated by considering the three‐dimensional flow net by stratigraphic units. Hydraulic head distribution maps for 27 stratigraphic units in the western Canada sedimentary basin were prepared, and those from the Upper Devonian Beaverhill Lake Formation, Woodbend and Wabamun Groups and the Lower Cretaceous Mannville Group and Viking Formation are illustrated. The low fluid‐potential drain that exists within the Upper Devonian and Carboniferous carbonate rocks itself contains drainage channels belonging to different fluid potential subsystems. Excellent examples of these subsystems are found in the carbonate reef complexes of the Beaverhill Lake Formation and the Woodbend Group. Drawdown of the fluid potentials by some of the low fluid‐potential channels is reflected through up to 2500 feet of strata and across a major unconformity. In general, relatively highly permeable beds significantly affect the regional fluid potential distribution, although the dominant features are topographically controlled. An apparently three‐dimensionally closed hydraulic head low in the Viking Formation is most probably the result of a chemico‐osmotic potential coupled with the regional elevation and pressure potential. Copyright 1969 by the American Geophysical Union.