Integrating CO2 storage with enhanced gas recovery (CSEGR) and geothermal energy extraction: A new semi-closed loop horizontal well structure for high-temperature depleted gas reservoirs

Abstract

As the global energy crisis intensifies and environmental challenges mount, the pursuit of clean and sustainable energy sources has become paramount. This paper explores the integration of Carbon Capture, Utilization, and Storage (CCUS) technologies with geothermal energy development. A novel semi-closed loop horizontal well structure (SCHW) is proposed for the combined CO₂-Enhanced Gas Recovery and Carbon Plume Geothermal Systems (CSEGR-CPG system). A numerical model is established to evaluate the performance of CSEGR-CPG system with SCHW. The research results indicate that in the CSEGR-CPG system with SCHW, under the reservoir and injection-production conditions described in this paper, the backward cycle of SCHW is used in the CSEGR phase and forward cycle of SCHW is used in the CPG phase to obtain the best performance. The study highlights the influence of permeability and thickness on the migration of CO₂ and heat recovery effect within reservoir. Overall, this study demonstrates the effectiveness of this integrated approach in enhancing gas recovery while enabling geothermal energy production, offering a viable pathway for the reutilization of depleted gas reservoirs.