Gas Cycling the Carson Creek Field

Abstract

Abstract The Carson Creek - Beaverhill Lake field comprises two retrogradegas-condensate reservoirs being produced under full-scale gas cycling.Production consists of rich gas from which liquids are stripped, the residuegas being injected back into the reservoirs. Make-up gas from the adjacent Carson Creek North oil field is injected to maintain the original reservoirpressure, thereby minimizing condensation of liquid in the reservoirs. Theengineering aspects of this scheme involve a choice of well patterns andlocations, and of producing and injection rates, the prediction of rates andrecoveries, and the design of facilities. A potentiometric model study was usedas the basis of the reservoir study. The main features of the scheme are:only one injector and one large irregular cycling pattern are used for eachreservoir, utilizing widely spaced wells;the installation of thefull-scale scheme was based mainly on theoretical calculations, with noproduction history or pilot test data available. It is estimated that 76 percent of the pentanes plus will be recovered under cycling, as compared with 45per cent under primary pressure depletion. Introduction The Carson Creek field is a retrograde gas condensate field located 105miles northwest of the city of Edmonton and 8 miles north of the town of Whitecourt. It is the most southerly hydrocarbon accumulation found to date inthe Swan Hills Beaverhill Lake reef trend. As presently delineated, the fieldencompasses approximately 18,000 acres in Townships 60 and 61, Ranges 11, 12and 13 W5M (Figure1). The original raw gas-in-place was approximately330 Bcf. The discovery well, Mobil Whitecourt Carson 13-12-61-12, was cased asa potential producer from the Upper Devonian Beaverhill Lake reef in March of1957. Since that time, eleven additional wells have been drilled. In March of1962, an application was made to the Conservation Board to cycle this field.The plant was built and cycling began in December, 1962. (This means that, attime of writing, the field had a production history of approximately one year.)The field has now been unitized, with Socony Mobil Oil of Canada, Ltd., as theoperator.