Deep Geothermal Heat Storage Under Oilsands— Can We Use it to Help Oilsands Industry? New EGS Concept Proposed

摘要

The research into a geothermal energy option for a deeper crystalline basement heat source in the Northern Alberta basin as a potential artificially fractured subsurface heat exchanger to deliver heat for oilsands processing and/or deep geothermal energy for heating to offset CO_2 emission is currently underway as part of the University of Alberta Helmholtz-Alberta Initiative (HAI) geothermal energy project. Temperature logging into old Precambrian granites beneath 0.5 km thin sedimentary column in the 2.35 km deep Hunt well near Fort McMurray shows that there is a rather limited amount of heat in granites. It would require drilling some 4-5 km to get to 80-100 0C in Fort McMurray area and 120-150 °C in Peace River area, respectively. This temperature is not sufficient to generate steam for the in-situ recovery of heavy-oil and bitumen but the demand for hot water for surface processing is limited to only 40-70 °C. Our current effort is to generate hot-water through engineered gothermal systems (EGS) for surface processing of bitumen in the Fort McMurray area as an alternative to burning natural gas for this purpose. At the same time, relatively high temperature gradient areas can serve as a heat source for communities. In this paper, we propose a new concept for greening oilsand energy through the new EGS system. This system is planned to deliver heat for the processing of mined oilsands or pre-heating using inclined to horizontal drillholes used to create artificial heat exchange space and use deep underground heat beneath oilsand.