Using Geothermal Energy to Reduce Oil Production Costs

The economic impact of the Covid-19 pandemic on the oil industry has been devastating. The decline in demand and price collapse have been particularly disruptive for shale oil extraction which is inherently more expensive than conventional operations. Survival and continuing operations will depend partly on reducing operating costs, and a ubiquitous and substantial cost in oil production is electrical power used primarily for pumping the wells. The Bakken play is particularly vulnerable because there is not an adequate electrical grid in the region. Many Bakken fields rely on generators burning propane, gasoline or diesel fuel at costs about $0.28 per kWh - four times grid costs. Shale plays have the unique characteristic of multiple wells per pad so that the total fluid available can be enough for coproduction of 10s to 100s of kW with an ORC on site. Bakken temperatures range from 100 °C where heat flow is low and the Bakken is shallower on the eastern margin of the shale play to 140 °C where heat flow is high in and the Bakken is deeper in the center of the basin. Water-rich carbonate rocks underlying the Bakken have higher temperatures and could generate several MW of power at local sites. Three scenarios for the higher power operations include: 1) Recompleting marginally economic existing oil wells in the overlying Lodgepole Formation and converting to water production; 2) Installing ORCs on the many water flood projects in the basin; 3) Drilling dedicated well fields for geothermal power production. After use in the ORCs, the hot waters could be used for low-cost space heating and further reduction of energy costs. An average submersible pump requires 16 kW, so, for example, if an ORC generated 160kW it could supply sufficient electricity to pump 10 wells.