美国能源部地热钻井技术研发最新部署及干热岩开发示范创新实践OA

Geothermal energy is the only base load power among the major renewable energy sources.Hot dry rock(HDR)is a high temperature rock mass buried in the deep earth without connate water or with a little water,which can form an enhanced geothermal system reservoir through hydraulic stimulation,and a considerable amount of geothermal energy can be extracted.There are two main technological challenges associated with the development of HDR geothermal resource,i.e.,very hard rock,such as granite or basalt limits the rate of penetration(ROP),and the temperature of the drilling system exceeds the operational limits of electronic tools like measurement while drilling(MWD)and steerable rotary tools.In recent years,the Utah FORGE project funded by the U.S.Department of Energy(DOE)provided an opportunity to test new drill bit technology and optimize drilling procedures to deliver a step change in ROP performance and drilling cost reduction.In this paper,the deployment of geothermal drilling technology R&D in the recent development plan of DOE Geothermal Technology Office is reviewed,the application of the redesign workflows based on physical limits in the drilling practice of the Utah project is selective analyzed,and the main areas covered by the multiple plans and projects funded by DOE in terms of geothermal drilling technology as well as the lessons learned from the Utah project in exploring and practicing drilling operation optimization are summarized.