Disposal of power plant CO2 in depleted oil and gas reservoirs in Texas

Abstract

Texas accounts for more than 10 percent of carbon dioxide (CO 2 ) emissions from power plants in the U.S. and has a large concentration of oil and gas reservoirs which could serve as disposal sites. Two of the largest power plants, accounting for 20 percent of the state's CO 2 emissions, have adequate reservoir volumes within 50–100 miles to allow CO 2 disposal for 30 years or more. However, the majority of these fields are still producing and will not be sufficiently depleted and ready for CO 2 injection for 10 years or more. Oil reservoirs are economically preferred to gas reservoirs since operators are willing to buy the CO 2 for enhanced oil recovery. For retrofit to existing power plants, estimated costs are $50–$65/ton CO 2 for disposal in nearby gas reservoirs and $40–$55/ton CO 2 for disposal in oil reservoirs. For advanced technologies in future power plants estimated costs are $15–$25/ton CO 2 for disposal in gas reservoirs, and $5–$15/ton CO 2 for disposal in oil reservoirs. Avoided costs are approximately 50 % higher. Comparative cost differences between power plants using coal or natural gas are discussed. Technical and regulatory factors which may limit the use of some categories of reservoirs as disposal sites are identified.