Shallow Subsurface Occurrence of Oil-Bearing Zones in Middle Mississippian Strata of Northeastern Oklahoma: An Analog for the Distribution of Reservoir Facies and Hydrocarbon Traps
Cory Godwin, Darwin Boardman, Sal Mazzullo, Brian Willhite, James Puckette, and Michael Grammer
A northeast-southwest oriented cross-section constructed using six shallow slim-hole cores along the western edge of the Mississippian outcrop belt in Mayes County, Oklahoma demonstrates the influence of observed regional stratigraphic relationships, carbonate depositional facies, and diagenesis on the distribution potential reservoir facies Middle Mississippian succession based on the occurrence of oil-bearing zones. Oil-staining in the Pierson Formation (Osagean) occurs within an anomalously thick section currently interpreted to be associated with carbonate build-ups. In the Reeds Spring Formation (Osagean) oil-staining occurs within the upper tripolitic facies. The tripolite has been interpreted to have developed in association with a regionally extensive unconformity following Reeds Spring deposition. Within the Mayes County cores the Reeds Spring is overlain unconformably by the Mayes Group (upper Meramecian and Chesterian). The occurrence of the tripolitic facies in the Mayes County cores is coincident with the thickest overall Reeds Spring section, while in cores with thinner Reeds Spring Formation there is no tripolite and the Mayes Group rests unconformably on cherty carbonate mudstone. This supports tripolite development during the post-Reeds Spring unconformity. It also suggests that the removal and preservation of the tripolitic facies below the pre-Mayes Group unconformity is a controlling factor in the distribution of this potential reservoir. In the Mayes Group (Meramecian and Chesterian) oil-bearing zones are associated with coarse-grained skeletal grainstones.
AAPG Search and Discovery Article #90176©AAPG Mid-Continent Meeting, Wichita, Kansas, October 12-15, 2013