WINNIPEGOSIS FORMATION, PLATFORM MARGIN: RESERVOIR CHARACTERIZATION

The Winnipegosis Formation is a Middle Devonian carbonate unit within the Elk Point Group in the Williston Basin and the larger Elk Point Basin. The Elk Point Group is composed of three members; the lowest stratigraphically is the Ashern Formation, which is overlain by the Winnipegosis, and then the Prairie Evaporite. The platform of the formation has been divided into three geographic platforms in North Dakota: a western, southern, and eastern. The formation within North Dakota has produced about 9.9 million barrels of oil. Significant production from the formation in North Dakota has been completely from the western platform. Within the western platform production is very limited with the most prolific production coming from Temple Field located on the Nesson Anticline in Williams County. Temple Field production began in 1982 and the field has currently produced about 6.5 million barrels of oil. Temple Field production is along the platform margin and characterized by patch reefs. McGregor Field is directly southeast of Temple Field along the anticline and began production in 2000 and has produced 1.5 million barrels of oil. The Winnipegosis has been studied very little since the late 1980's because of limited production and other formations becoming of more interest. The purpose of this study was to integrate geological and petrophysical workflows to better characterize the platform margin of the Winnipegosis Formation. A complete in-depth examination of the reservoir properties of the Winnipegosis Formation of the platform margin allowed for a better understanding of the lithofacies and porosity and permeability within the platform margin of Temple and McGregor Fields. Core descriptions and core data were used to divide the formation into facies and correlated to well log data. A three-dimensional reservoir model was created of Temple and McGregor Fields to better understand the reservoir properties of this portion of the platform margin.