The Potential Impacts of Co-Produced Geothermal Waters

Will Gosnold, Hossein Salehfar, Zhengwen Zeng, and Mike Mann
School of Engineering and Mines, U. North Dakota, Grand Forks, ND

Electrical power generation from co-produced oil field geothermal waters is technically and economically feasible with installation of binary power plants in unitized fields and individual wells producing sufficient volumes of water. The application of organic Rankine cycle (ORC) technology in binary power plants allows use of temperatures as low as 90 C for power production. Use of existing infrastructure eliminates drilling and well completion costs, thereby reducing much of the upfront cost of geothermal electrical power production. We envision at least two significant impacts of pursuing development of this low-to-intermediate temperature (LTIT) geothermal resource for electrical power production. The first impact addresses the question of how much total electrical power could be generated and how much of the nation’s electrical power needs could be met. Recent estimates of the energy in currently co-produced geothermal waters in 31 oil and gas producing states range from 4,591 MW at 100 C to 21,933 at 180 C. These estimates constitute approximately 1.3 to 6.8 percent of the electric power consumption in the 31 states in 2004. However, the potential energy resource contained in LTIT waters in sedimentary basis is estimated to be thousands of GW. Therefore, development of only a fraction of the LTIT resource using abandoned or capped wells in oil and gas fields could establish an extensive geothermal power infrastructure and provide a sustainable and secure domestic energy resource. The second impact would be a significant reduction in CO₂ emissions from electrical power generation. Approximately half of global anthropogenic CO₂ derives from coal-fired power plants. Large-scale development of binary power plants using LTIT geothermal resources has the potential to make a significant reduction in anthropogenic greenhouse gas production.

AAPG Search and Discover Article #90078©2008 AAPG Annual Convention, San Antonio, Texas