Theory, technologies, and practice of oilfield-geothermal co-development in the Bohai Bay Basin

Abstract Driven by the global energy transition and China's dual-carbon goals, oil and gas field development faces challenges in achieving sustainable development. Oilfield-geothermal co-development (OGC) offers a pathway for revitalizing mature oilfields and supplying low-carbon energy. This article describes the resource endowment, genetic mechanisms, and oil-heat-water co-occurrence relationships of geothermal resources in oilfields, examines the theory and key technologies for OGC, and proposes an integrated technical system. Development modes include waste-heat recovery from produced fluids at central processing stations, integrated utilization of waste heat from high-temperature oil wells, same-well co-production of oil and geothermal resources, and same-layer enhanced fluid production and heat extraction. The technical system includes evaluation and conversion of existing oil and gas wells, reservoir stimulation and efficient heat extraction, surface energy conversion and integrated utilization, and life-cycle system integration with intelligent control. The Dongyi project in Shengli Oilfield illustrates field implementation of this framework. Current challenges include the long-term reliability of materials and equipment in high-temperature environments, accurate prediction and control of multiphysics coupling in complex reservoirs, and the potential interference and coordinated optimization between geothermal development and remaining oil and gas recovery. Future OGC development is expected to expand into deeper subsurface domains, integrate the development of oil and gas, geothermal energy, and associated mineral resources, and pursue breakthroughs in key technologies and critical equipment.