Heavy oil production assisted by super-long gravity heat pipe geothermal energy utilization

Abstract

Heavy oil exploitation is traditionally associated with high energy consumption due to the significant heat required for thermal recovery and production processes. Conventional techniques often struggle to efficiently maintain wellbore temperatures, particularly in the upper sections. This study proposes a super-long gravity heat pipe (SLGHP) as a sustainable and energy-efficient solution to optimize wellbore temperature distribution particularly by elevating the wellhead temperature without additional energy input. By transferring heat from deep, high-temperature regions to the cooler upper sections, the SLGHP enhances the thermal performance of heavy oil production systems. A numerical model is developed to investigate the coupled heat transfer dynamics among the SLGHP, steel pipe wall, production fluid, and surrounding geological formation. The performance of SLGHP is evaluated under various operational and geological parameters, including water cut, production rate, geothermal gradient, and formation thermal conductivity. Results demonstrate that SLGHP can typically improve wellhead temperature by up to 20 °C, reducing production fluid viscosity by 67.8 % compared to conventional system. Higher water cuts and geothermal gradients further enhance thermal optimization, with wellhead temperature improvements exceed 30 °C under high geothermal gradient (0.06 °C/m). Lower production rates maximize the system efficiency, while formations with lower thermal conductivity minimize heat loss and further enhance thermal performance. This study highlights the potential of SLGHP technology to overcome the limitations of conventional thermal recovery methods, enabling sustainable and energy-efficient heavy oil production.