ABSTRACT

Considerable data have become available from additional drilling in the Flaxton Field area, Burke County, North Dakota, and it is now possible to distinguish two additional intervals which lie at the top of the Mission Canyon: the Coteau and the Dale. These intervals were previously miscorrelated as Bluell.

Flaxton Field produces oil from a structural-stratigraphic trap in the Mississippian Mission Canyon and Charles Formations. The field was discovered in 1956 with completion of the Texota 1 Sorum. This and other early wells in the field were completed in the Midale and Nesson intervals of the Charles. The field was rediscovered in 1981 with completion of the Monsanto 1 Bird in the Coteau interval of the Mission Canyon. Until recently the Coteau as well as the Dale intervals have commonly been lumped together, and miscorrelated to the Bluell interval of the Mission Canyon.

The Mission Canyon Formation in the more recently developed part of the field is a limestone with variable, but generally low porosity and permeability (usually less than 15 percent and 1 md). Most of the reservoir rocks were deposited in shallow-marine shoals which were sometimes exposed subaerially. Diagenetic changes, especially cementation, have had an important effect on the reservoir.