Geothermal Utilization of Abandoned Oil and Gas Wells: A Review

Geothermal energy is considered as one of the renewable energy sources to replace fossil fuels such as petroleum due to its reliability, sustainability, resource abundance and low environmental impact. The petroleum industry produces a large number of abandoned wells every year. Using abandoned wells for geothermal development can not only alleviate energy problems, reduce the initial investment of geothermal development, but also effectively control the pollution caused by abandoned wells. Combined with the distribution of geothermal resources of abandoned wells, this paper analyzes the feasibility of the reconstruction of abandoned wells, summarizes the geothermal development technology of abandoned oil wells and reviews the current cases of geothermal resources utilization of abandoned oil wells in the world, points out the existing challenges. It is recommended to start from the overall trend of geothermal development, focus on the development of high-efficiency working fluids, optimize model prediction, broaden the utilization of geothermal energy, improve the heat extraction performance of abandoned well systems, establish intelligent decision-making and risk/opportunity assessment mechanisms, and strengthen research on ground supporting facilities.