Upper Ordovician Yeoman Formation source rocks are thermally mature in the south-central portion of the study area (T. 1-16, R. 30W1-30W2). Using conservative values yields a potential volume of oil generated of approximately 19.9 billion barrels. Under a 15% expulsion and trapping efficiency scenario, the potential reservoired oil-in-place is approximately 2.9 billion barrels.
This study analyzes the following:
1. source rock geochemistry, thermal maturity, and geothermal regimes
2. formation water characteristics
3. oil migration pathways, both within the maturity window and outside of it
4. charge and trapping potential
5. presence or lack of pressure breaks and their significance.
Oil migration distance can be documented to a minimum of 55 km and possibly up to 100 km updip of the source rock maturity edge. The trapping potential of specific structures is a function of charge received and rate of structural closure relative to the calculated tilt of oil/water contacts. Hydrodynamic flushing may not substantially impact trapping potential, except in areas of greater than 8 to 10 m/km of tilt. Based on the available data, our hydrogeologic analysis suggests that the Upper Ordovician oil play is largely structural. The primary risk in the play is oil charge and to a lesser degree, flushing. This report allows quantification of both of these risk factors and a method by which to high-grade areas of oil charge and entrapment potential.