Co-Produced Geothermal Power

William D. Gosnold and Anna M. Crowell
University of North Dakota

Advances in binary energy conversion technology, i.e., small organic Rankine cycle engines, have generated interest in the potential for electric power generation from low-to-intermediate temperature fluids in deep sedimentary basins. Estimates of the power that could be produced have been based on calculations of the energy stored in permeable formations, formation properties relevant to reservoir productivity and on total fluid production data from oil and gas databases. These general estimates indicate that large quantities of power could be extracted from many intracratonic basins using co-produced fluids and fluids pumped from hot permeable formations. Estimates of the resource potential for the Williston basin are on the order of 1020 Joules which implies a resource potential of several GW of electrical power. However, the water-to-oil production ratio (WOR) for the Williston basin is low, 1.22:1 based on 8,013 working wells in 2013. Other than the Bakken, the Madison (Mississippian) and the Red River (Ordovician) formations produce the greatest fluid volumes from the basin. Power production for the top ten producing wells in the Madison and Red River formations based on an exit temperature of 160 °F (71.1 °C) and an ambient air temperature of 60 °F (15.6 °C) for an ORC with 6 percent efficiency are approximately 671 kW and 814 kW respectively. Repeating the calculations for the unitized Madison and Red River fields yields co-production potentials of 3 MW for the Madison and 4 MW for the Red River. Thus, actual power production from co-produced fluids in the Williston Basin may be several orders of magnitude less than was predicted in earlier estimates.

AAPG Search and Discovery Article #90169©2013 AAPG Rocky Mountain Section 62^nd Annual Meeting, Salt Lake City, Utah, September 22-24, 2013