Experimental and visual investigation on energy-efficient and zero greenhouse gas emission post-steam-assisted gravity drainage heavy-oil recovery improvement

Abstract

Recent core-scale visualization studies performed by us have highlighted the promising potential of utilizing hydrocarbon solvents in alternating with steam injection for optimizing post-steam-assisted gravity drainage (SAGD) processes. This technique not only improves hydrocarbon recovery but also improves economic viability and reduces greenhouse gas (GHG) emissions. However, further investigations, including tests with non-hydrocarbon solvents and SAGD sandpack experiments, are necessary to provide robust comparisons and recommendations. This study focuses on SAGD sandpack experiments using both hydrocarbon (heptane) and non-hydrocarbon (carbon dioxide gas) solvents for post-SAGD applications. The experiments—conducted under reservoir conditions—demonstrated significant improvements in heavy-oil/bitumen recovery by up to 50 %, compared to conventional methods. Moreover, the use of non-hydrocarbon and liquid hydrocarbon solvents could eliminate the need for aggressive steam utilization, thus enhancing energy efficiency. Additionally, the potential for solvent recovery was evaluated to optimize the process further.