Reusing depleted oil and gas wells for geothermal energy: Feasibility, challenges, and a decision‐making framework for sustainable conversion

The conversion of depleted oil and gas wells into geothermal systems presents a unique opportunity to advance the global energy transition by reducing geothermal drilling costs, extending the utility of legacy infrastructure, and mitigating methane emissions from abandoned wells. This review synthesizes the current state of knowledge on the feasibility, challenges, and opportunities of geothermal repurposing, explaining the interplay between geological factors, technical design, and operational strategies. It examines methodological advances, including analytical models, laboratory experiments, field tests, and numerical simulations, that assess geothermal potential and guide system optimization. Beyond technical aspects, the review also addresses economic viability, policy frameworks, and environmental implications. To bridge these dimensions, a structured decision‐making framework is proposed, integrating geological, technical, economic, environmental, and regulatory considerations to support evaluations of conversion projects. By consolidating these insights, this work positions geothermal repurposing of depleted wells as a practical and sustainable strategy for decarbonization, while identifying research priorities and policy needs essential for accelerating its deployment.