PROCESS FOR CONFINING STEAM INJECTED INTO A HEAVY OIL RESERVOIR HAVING A THIEF ZONE

摘要

The process is practised in the context of a pattern of steam injection and oil production wells being completed in the payzone of a reservoir. A laterally extending thief zone, high in the reservoir, is in fluid communication with the payzone. An array of gas injection wells is provided at the perimeter of the pattern. The gas injection wells are adapted to inject non-condensable gas into the thief zone. The process comprises injecting non-condensable gas into the thief zone while steaming and producing the reservoir with the pattern wells. Gas injection is conducted to maintain the pressure in the thief zone at the perimeter of the pattern substantially equal to that within the pattern.