There are several maturing waterfloods in the Medicine River/Gilby region of West-Central Alberta which are operating at high reservoir pressures, and are suitable candidates for enhanced oil recovery (EOR) by CO2 flooding. Potential CO2 supplies also exist in the region from various petrochemical, as well as sour gas and solution gas processing plants. A prototype reservoir was selected for a detailed "business case" study. CO2 flooding and geological storage were seen to be feasible in the prototype reservoir based on geological/ reservoir reviews, laboratory testing and reservoir simulation.
Economic parameters (payout periods for the investment, rates of return) on risk-weighted basis were moderate in light of front-end capital requirements for extraction, recycle and transportation facilities. The situation would change for the better if regional infrastructure for CO2 capture, extraction and transport is developed. This, in turn, is dependent upon adequate assured demand. On the other hand, demand won't develop unless there is appropriate infrastructure in-place. Fragmented ownership of the resource and of CO2-rich waste gas streams, as well as inertia favouring status quo, are some of the other challenges.
We present here a generalized "business case" for illustrating some of the issues of CO2-EOR implementation.
CO2-EOR is receiving increasing attention mainly because of the following emerging trends:
Increasing awareness of potential reserves addition by CO2 flooding in mature sedimentary basins such as the Western Canadian Sedimentary Basin (WCSB), based on performance of Weyburn and Joffre Viking CO2 flooding projects in WCSB, and also in various oil fields of West Texas Permian Basin.
Growing recognition of the importance of Carbon Capture and Storage (CCS) and anticipated incentives for CCS projects in value-added mode such as EOR.
Consensus that the main barrier to widespread implementation of CO2-EOR in Alberta is lack of supply and transportation infrastructure for CO2.
