Technical Status and Development Suggestions in Exploiting Geothermal Energy from Abandoned Wells

Geothermal energy, as one of the renewable energy resources replacing fossil fuels, is difficult to drill and utilize in a large-scale due to its high development cost. A large number of oil and gas wells are abandoned in the petroleum industry every year. If those wells can be used in geothermal energy development, it not only alleviates energy problems and reduces drilling costs, but also effectively controls pollutions from well abandonment. Therefore, the feasibility of the abandoned wells transformation was analyzed combining with the current research status of geothermal exploitation and the selection and utilization methods of target wells were elaborated. In addition, the transformation and heat extraction modes in abandoned wells were discussed in this paper. In general, the exploitation of geothermal energy from abandoned wells is still in the stage of theoretical and experimental research, far from large-scale industrial application. It is suggested to start from the overall trend of geothermal development, focus on key technologies of multi-lateral wells, improve the heat extraction performance of abandoned well systems, establish the intelligent decision-making and optimization system, and strengthen the research on ground supporting facilities. The results of the research and development suggestions will provide a guideline in obtaining geothermal resources from abandoned wells.