GEOTHERMAL DEMONSTRATION PROJECTS IN A SEDIMENTARY BASIN

The Geothermal Laboratory at the University of North Dakota is conducting geothermal power demonstrations projects in the Williston Basin in collaboration with US Department of Energy, Continental Resources, Inc. (CRI), Denbury Resources, Inc. (DRI), and Calnetix, Technologies LLC. The primary objective of these projects is to demonstrate the technical and economic feasibility of generating electricity from non-conventional, low-temperature (150 °F to 300 °F) geothermal resources using binary organic Rankine cycle (ORC) technology. The demonstration project with CRI will use low TDS water that is being produced at 875 gallons per minute at a temperature 210 °F. The project with DRI will use high TDS water that is being produced at 350 gallons per minute also at a temperature of 210 °F. The CRI project takes advantage of a secondary recovery water-flood in southwestern North Dakota. The potential power output from this project is 550 kW at a cost of $3,000 per kW. The DRI project will use water co-produced with oil and is currently in the planning stage. A key factor in the economics of these projects is the advance in binary power technology. Most ORC engines have an efficiency of about 8 percent to 10 percent. The Calnetix ORC engines will generate 125 kW with an efficiency of 12 percent. These projects are small, but the potential for additional development in hotter strata is promising. Our analysis of the entire Williston Basin using data on porosity, formation thicknesses, and fluid temperatures, reveals that 161 x 10⁶ MWt could be produced.