--> Abstract: Anhydritization of the Mississippian Frobisher Succession, Steelman Field, Southeastern Saskatchewan, by Arden K. A. Marsh and Hairuo Qing; #90039 (2005)

Datapages, Inc.Print this page

Anhydritization of the Mississippian Frobisher Succession, Steelman Field, Southeastern Saskatchewan

Arden K. A. Marsh and Hairuo Qing
University of Regina, Regina, SK

The Mississippian strata are the most important hydrocarbon producer in the northern Williston Basin, accounting for approximately 75% of known oil reserves in Saskatchewan. The Steelman Field is located on the northeastern flank of the basin, where hydrocarbons are produced predominantly from the Midale Beds, although there is also some limited production from the Frobisher Beds. The reservoirs within both of these units are characterized by highly variable porosity and permeability that are related to their complex depositional and diagenetic history.

The Frobisher succession in the Steelman Field is comprised of four shallowing-upward cycles that were deposited within a peritidal environment, with sabkha type anhydrites capping the upper two cycles. The hydrocarbon reservoirs within the Frobisher succession are typically found within a vuggy-fenestral grainstone-packstone facies that are common throughout each cycle. The porosity, however, is often occluded by different types of anhydrite, which severely restricts any possible production that may have occurred. Anhydrite filled fractures may also contribute to this reduced reservoir potential by forming migration barriers, restricting the lateral movement of fluids. The petrography of different types of anhydrite, their facies relationships, and their effects on any reservoir potential within the upper two cycles of the Frobisher succession will be addressed in this presentation.

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