Optimizing injection and production parameters for enhanced thermal energy utilization in steam-assisted gravity drainage: A semi-analytical analysis

This study first develops a semi-analytical model to optimize the liquid production rate or production–injection ratio throughout the steam-assisted gravity drainage (SAGD) process. Next, three semi-analytical approaches are formulated for different application scenarios. Finally, after verifying the accuracy of these approaches, we discuss their application in injection–production optimization. For ongoing projects, integrating approaches 1 and 2 effectively adjusts liquid production rates, leading to improvements in oil production and thermal energy utilization. For the Celtic Oilfield project, strategic adjustment of liquid production rates results in a 22.9% increase in oil production and an 18.6% reduction in the cumulative steam–oil ratio (CSOR) compared to the baseline. Approach 3 is particularly well suited for designing injection and production parameters for new projects. Implementing the optimized parameters from approach 3 enhances oil production and thermal energy utilization. For the SAGD project in Celtic Oilfield, this results in a 30.6% increase in cumulative oil production and a 12.9% reduction in CSOR. The optimal parameters designed for both the SAGD project in the Celtic Oilfield and in the Lvda Oilfield demonstrate the adaptability of approach 3 to varying reservoir conditions. This study presents efficient and accurate approaches for optimizing injection and production parameters to enhance thermal energy utilization in SAGD, applicable to both current and future projects.