1-D/2-D/3-D Petroleum System Model of the Western Canada Sedimentary Basin

Debra K. Higley¹, Laura Roberts¹, Mitch Henry¹, Michael Lewan², and Doug Steinshouer^3
1 U.S. Geological Survey, Denver, CO
² U. S. Geological Survey, Lakewood, CO
³ GeoLukas, Denver, CO

The 3D petroleum system model of in the Western Canada Sedimentary Basin is a stacked sequence of Devonian through Holocene horizons that comprise the major reservoir, source, and seal intervals. Horizons were generated and modeled using Dynamic Graphics earthVision and IES PetroMod software. 1D burial histories for 38 wells across the basin were constructed, and were externally calibrated using published vitrinite reflectance data, drillstem test temperatures, and maps of heatflow, isopachs of eroded section, and paleogeography. Preliminary conclusions based upon the results of the models are the following:

1) The northeast-trending Sweetgrass Arch subdivides the basin such that Paleozoic and Mesozoic reservoirs located east of this structure appear to be mainly charged from the northwestern Williston Basin, based on modeled flowpath directions and basin geometry.

2) Modeled hydrocarbon flowpaths in the Alberta Basin are mainly from the west.

3) Migration distances for oil and gas in Mannville reservoirs in Alberta are commonly 200 km or more.

4) Paleozoic through Jurassic formations below the sub-Mannville unconformity are truncated by erosion, and contain the probable main sources of hydrocarbons for the Mannville Group tar sands in northern Alberta.

5) The Devonian-Mississippian Exshaw/Bakken and Duvernay Formations are probable major source rocks for the Mannville Group tar sands in northern Alberta based on geometry, modeled hydrocarbon flow paths and extent, and thickness and thermal maturity of these intervals.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005