Meissner Keys to the Bakken Petroleum System, Williston Basin

Stephen Sonnenberg and Aris Pramudito
Department of Geology, Colorado School of Mines, Golden, CO

The Devonian-Mississippian Bakken Petroleum System of the Williston Basin has been the focus of several cycles of exploration activity since the 1950s. The current development of the middle member of the Bakken with horizontal drilling has resulted in the most significant cycle to date.

Meissner keys about the Bakken Petroleum System include: abnormal pressure created by hydrocarbon generation; high resistivity Bakken shales associated with maturity; and minimum temperature associated with mature source rocks (165^oF).

The Bakken Petroleum System consists of organic rich shale members of the Bakken (upper and lower shales) and genetically related oil reservoirs (middle Bakken member, lower Lodgepole, and upper Three Forks). The middle member of the Bakken is the most significant reservoir in the Bakken Petroleum System and has lithologies ranging from carbonates to sandstones to siltstones.

Several large areas are currently being developed in the middle member of the Bakken. The giant Elm Coulee field of Richland County Montana has been horizontally drilled since 2001. The field has produced in excess of 41 million barrels of oil and 24 BCF gas from over 400 horizontal wells and has an estimated ultimate recovery of over 200 million barrels. In North Dakota the Robinson Lake and Parshall field areas are currently being developed. Further drilling will determine if this area has similar potential to the Elm Coulee area.

An understanding of Meissner keys, Bakken tectonics, stratigraphy and diagenesis may lead to the discovery of new resource play areas in the Bakken.

AAPG Search and Discovery Article #90092©2009 AAPG Rocky Mountain Section, July 9-11, 2008, Denver, Colorado