| Abstract |
Alberta produces roughly 85% of Canada’s oil and gas and contains a large inventory of abandoned oil and gas wells (AOGWs). These inactive wells pose environmental risks, particularly through methane leakage and hydrocarbon migration into groundwater. Converting AOGWs into geothermal wells offers a practical way to reduce emissions, save on drilling costs, and avoid the non-revenue burden of conventional plugging and abandonment. The configuration proposed in this study is a closed-loop, double-pipe heat exchanger retrofit, using water as the working fluid. A multiphysics-based, computationally efficient ground–wellbore model, validated against field data, is applied to Alberta’s AOGWs. Our earlier statistical assessment showed that approximately 80% of Alberta’s abandoned petroleum wells have sufficient thermal potential for direct heat use and electricity generation when water is injected at a rate of 1.6 kg/s with an inlet temperature of 15 °C, with all wells deeper than 500 m. This share rises to 100% when the injection temperature is reduced to 10 °C. For space heating, most wells can supply heat pump use with an average temperature gain of 5.1 °C, while for district heating, the gain averages 44.5 °C. For wells producing water above 90 °C, injection temperature is adjusted to 70 °C, yielding an average production temperature of 110 °C for electricity generation using a geothermal-driven Organic Rankine Cycle. The results indicate that suitable wells can be converted into geothermal power sources, offering a scalable pathway to low-carbon heating and electricity generation in Alberta while supporting methane reduction and broader energy transition goals. |