Carbon Dioxide For Enhanced Oil Recovery In Canada

Abstract

Abstract major miscible so/vent in Canada and describes Shell Canada's carbon dioxide exploration efforts over the last few years. Enhanced oil recovery, specifically miscible flooding, has been recognized as a technically and economically feasible method for adding reserves and productive capacity to Canada's light and medium oil. The fiscal regime has been altered by both the federal and provincial governments to encourage miscible flooding development. As a result many projects have been initiated with others being evaluated and designed. This paper analyzes the history and the direction of miscible flooding in the United States, where carbon dioxide is becoming the predominant miscible solvent. The potential for future use of carbon dioxide in Canada is specifically addressed:potential oil recoverysolvent supply, andeconomics. Shell's carbon dioxide exploration play currently underway is also discussed. Introduction Since the 1973 Arab oil embargo and subsequent rapid rise in oil price, oil self-sufficiency in Canada has been expressed as a national desire. Yet, since that time, yearly conventional oil production has not been replaced. Figure 1 shows that domestic crude oil supply and demand are temporarily in approximate net balance, primarily due to the recent substantial reduction in the latter(1). Canadian demand is forecast to exceed production from established reserves and new discoveries by approximately 100,000 m3 per day (630,000 bbls/day) by the early 1990s. Canada must therefore turn to the non-conventional sources to achieve self-sufficiency. This paper examines the contributions enhanced oil recovery (by miscible flooding) may be able to make in achieving oil self-sufficiency. An analysis of the history and future direction of miscible flooding in the United States, where the petroleum industry has changed from using light hydrocarbons to using carbon dioxide as the predominant solvent, is given. From these analyses carbon dioxide could emerge as the dominant solvent in Canada in the future. Light and Medium Enhanced Oil Recovery Potential in Canada Two-thirds of the original oil-in-place is usually left in the ground after conventional (water flood) recovery techniques have been applied. Miscible enhanced recovery processes involve the injection of a solvent such as carbon dioxide nitrogen or light hydrocarbons (ethane, propane and butane) to mobilize some of this remaining oil. Miscible flooding has the potential to add 300 to 400 E6M3 (1.9 to 2.5 109 bbls) to Canada's remaining recoverable oil reserves. As shown in Figure 2 this reserve could increase Canada's remaining recoverable reserves by approximately 50% (2, 3, 4). This addition alone will not solve Canada's future oil shortage but can make a significant contribution toward the goal of eliminating reliance on imported crude oil. Miscible flooding in the United States has matured to a greater degree than in Canada. The United States experience and direction may give a strong indication of how the future will unfold in Canada.