ABSTRACT

The Outlook Field was discovered in December, 1956, by the Amerada Petroleum Corporation No. 1 Tange, C NE SE, Section 20, Township 36 North, Range 53 East, Sheridan County, Montana, with completion in the Interlake formation of Silurian age. Subsequent nearby wells have been completed in the Red River formation of Ordovician age, the Winnipegosis formation of Middle Devonian age and the Ashern formation of Middle Devonian age. Therefore, presently, the Outlook field has production from the Winnipegosis, Ashern, Interlake and Red River formations. Present reservoir characteristics indicate that the Winnipegosis, Ashern and Interlake formations repre­sent a common reservoir with intercommunication by a fracture and vug system and is referred to as the "Outlook Pay". The top of the zone is called on the first porosity in the Winnipegosis as variably developed from 15 to 35 feet below the base of the Prairie Evaporite.

Structural accumulation appears to predominate over possible stratigraphic reservoirs in the field. The reservoir rock varies from a coarse "clastic" dolomite to fossil fragmental dolomite with intervening lithographic textures. Reef structures are not identifiable. Dolomitization has greatly modified the original sediments.

The total production from the "Outlook Pay" as of November 30, 1957, was 109,404 barrels of low sulphur, 39.1° to 39.4° API, dark brown to black crude. The total production of the Ordovician reservoir as of November 30, 1957, was 24,245 barrels of low sulphur, 34.1° API, black crude.