Abstract: Geochemical Comparison of Paleozoic Oils, Wlliston Basin, U.S.A.

JARVIE, D. M., P. R. WALKER, and L. C. PRICE

Oils from the Paleozoic interval in the Williston Basin were typed using light hydrocarbon data in combination with other published results. The light hydrocarbon data were complemented with other chemical analysis including sulfur, aromatic hydrocarbons, and biological marker analyses.

Comparison of light hydrocarbon data from Bakken and mid-Madison oils from the Williston Basin shows two distinct homologous oil types with 2 possible sub-groups each. The mid-Madison oils are enriched in cyclic and aromatic compounds while the Bakken oils are depleted. While exsolution of gases and light oil fractions from Bakken oils is a possible explanation of a portion of these differences, this is not likely the reason for these differences based on other oil characteristics. A Lodgepole mound oil from Stark County, North Dakota is shown to type as a Bakken oil type of lower maturity than typical Bakken oils.

Other oils characterized and typed in this work using light hydrocarbon data include oils from the Interlake, Winnipeg, Red River, Winnipegosis, Dawson Bay, Duperow, Nisku, Bakken, Lodgepole, Mission Canyon, Charles, Kibbey, Heath, Tyler, Amsden, and Spearfish reservoirs.

AAPG Search and Discovery Article #90946©1997 AAPG Rocky Mountain Section Meeting, Denver, Colorado