WorldWide Drilling Resource

43 WorldWide Drilling Resource ® JULY 2014 Coproduction of Geothermal Resources from Oil and Gas Adapted from Information by the U.S. Department of Energy The U.S. Department of Energy’s (DOE) Geothermal Technologies Program (GTP) conducts research, development, and demonstration projects throughout the nation on coproduced and geopres- sured geothermal energy sources. The American Recovery and Reinvestment Act of 2009 expanded GTP’s demon- stration work into geopressured fields and natural gas fields. On average, 25 billion barrels of hot water are produced from oil and gas wells within the U.S. every year. This hot water has been an inconvenience requiring costly disposal in the past. However, it is now viewed as a resource which could be used to produce elec- tricity for field operations or sold to the grid. Coproduced geothermal resources could deliver near-term energy savings, diminish greenhouse gas emissions, extend the economic life of oil and gas fields, and profitably utilize abandoned oil and gas field infrastructure. Innovative technologies are increas- ing the geothermal resource base by using lower-temperature fluids. These technologies use a binary Organic Rankine Cycle (ORC), which transfers heat from geothermal fluid (mostly water) to a second fluid which vaporizes at a lower temperature and higher pressure than water, and drives a turbine to pro- duce electricity. A system of this type is closed-loop with minimal emissions. The University of North Dakota began a project to demonstrate the technological and economic feasibility of electricity generation using ORC technology. The system is installed at an oil field in western North Dakota where geothermal fluids are found at depths of 10,000 feet. A team of indus- try engineers, scientists, and project developers will use these fluids to oper- ate an on-site power plant for two years, and models will be created for ORC energy production. Another coproduction project is tak- ing place in Liberty County, Texas. Universal GeoPower, LLC will install, operate, and report data from a modu- lar, replicable power plant at an oil and gas well. Texas is important for geothermal development due to the more than 37,000 possible sites in the state and neighboring Gulf Coast, which could repli- cate power plant technology. Universal GeoPower estimates more than 7800 megawatts of power could ultimately be produced, allowing four trillion stan- dard cubic feet of otherwise abandoned natural gas to be recovered. This devel- opment would also create a significant number of jobs in the region. The Rocky Mountain Oilfield Testing Center in Wyoming was one of the first projects to validate the use of coproduced geother- mal fluids from oil and gas wells for power generation. The binary cycle plant is pic- tured here.