Effectiveness of Natural Gas Condensate as a Viable Solvent in ES-SAGD Processes: An Experimental Investigation Using a 3-D Physical Model

This study presents an experimental evaluation of the ES-SAGD process to better understand the recovery mechanisms, determine the optimized solvent concentrations, and enhance the overall process efficiency. Conducting three-dimensional physical model experiments (3DPMEs) of ES-SAGD poses significant challenges due to their complexity, cost, labor intensity, and time requirements. In this work, 3DPMEs were performed using varying concentrations of natural gas condensate as a solvent, chosen for its field availability and cost-effectiveness compared to pure solvents. A baseline 3DPME of conventional SAGD was also conducted for comparative purposes. Key aspects measured in this work included oil recovery factor, oil rate, water cut, cumulative steam–oil ratio (cSOR), cumulative gas produced and its composition, gas–oil ratio, and energy–oil ratio. Results demonstrate that adding natural gas condensate in ES-SAGD significantly improves bitumen recovery rates over baseline SAGD. The optimal solvent concentration was identified as 10% condensate with steam, which maximized oil production rates and reduced water cut. The cSOR for 10% solvent was approximately 2.83, compared to 7.6 for conventional SAGD experiment at 2 pore volume injected. This study highlights the potential of solvent-aided thermal recovery to significantly reduce the environmental impact of the oil sands industry, offering a pathway to lower greenhouse gas emissions and capitalize on carbon tax incentives.