Deep Basin, Alberta: ABSTRACT

Abstract

The Deep Basin, Alberta, is the site of a major gas accumulation which will have a profound impact on the North American energy scene. Approximately 20% of the total western Canadian drilling activity over the past year has been within the limits of the Deep Basin. Hydrocarbons have been found in 20 rock units ranging in age from Permian to Late Cretaceous. The majority of the reserves are contained within the Lower Cretaceous Spirit River Group and the Jurassic Nikanassin formation. Spirit River sediments were deposited in a series of transgressive and regressive cycles which can be mapped by gross lithologic characters and verified by sedimentologic and paleontologic criteria. The most favorable reservoirs are developed in chert-granule and fine-pebble conglomerates and associated medium-grained sandstones which are characteristic of a beach environment. Finer grained, poorly sorted sandstones of the foreshore facies form the reservoir for tight-formation gas. An even larger resource of tight-formation gas is found in the fluvial sandstones of the Nikanassin which present the same technologic challenges to economic development as their Spirit River equivalents. Detailed petrophysical studies have been utilized in the design of drilling and completion programs and the interpretation of potential pay horizons. The current oversupply of gas in western Canada will result in the deferment of tight-sand gas production until additional markets become available. End_of_Article - Last_Page 669------------