Energy Performance of Thermocable-Assisted SAGD for Heavy Oil Reservoirs: Heat-Loss Mitigation, Steam Chamber Development, and SOR Reduction

Steam-assisted gravity drainage (SAGD) remains one of the most effective thermal enhanced-oil-recovery technologies for heavy-oil reservoirs; however, its energy performance is strongly constrained by wellbore heat losses, delayed steam-chamber development, and an increase in the steam–oil ratio (SOR) under deep or thermally unfavorable conditions. This study develops a physics-based computational digital-twin framework for thermocable-assisted SAGD and evaluates the influence of steam temperature, oil viscosity, permeability, reservoir depth, thermocable linear power, and heating time on oil production and SOR. The model couples wellbore heat transfer, temperature-dependent viscosity reduction, steam-chamber geometry, heat-loss compensation by an electrical thermocable, and production response. The results show that increasing steam temperature from 220 to 300 °C raises the oil rate by approximately 13–15% and reduces SOR from about 2.47 to 2.30. Increasing oil viscosity from 300 to 1500 mPa·s decreases the oil rate by more than 25% and increases SOR above 3.0. Thermocable integration increases the oil rate by approximately 8–12% in the base scenario and reduces SOR by 5–10% compared with conventional SAGD. The highest relative benefit is obtained in deeper reservoirs, where additional heat input compensates wellbore heat losses and stabilizes the temperature profile. These findings indicate that thermocable-assisted SAGD can improve energy efficiency and extend the practical operating window of thermal recovery in heavy-oil reservoirs.