Decarbonization of Alkali–Surfactant–Polymer Flooding Enhanced Oil Recovery Process with Hydrogen under Uncertainty

Abstract

Among the existing enhanced oil recovery (EOR) techniques, the alkali−surfactant−polymer (ASP) flooding EOR technique has been proven to recover an additional 25−30% of the original oil in place, which is relatively higher than that of the other chemical EOR techniques. The field operations involved during the water flooding (WF) and ASP flooding EOR processes are highly CO 2 emissive, leading to increased global carbon footprint. However, due to the uncertainties associated with the operational parameters, the decarbonization of the ASP flooding EOR process becomes unreliable and challenging. Hence, the objectives of the present study are to decarbonize the ASP flooding EOR process using hydrogen and to improve the reliability of the decarbonization process under uncertain conditions. To decarbonize the ASP flooding EOR process, in the present study, CO 2 emissions from all the associated field operations were quantified, and subsequently, the major CO 2 contributing operations were identified for decarbonization. Followingly, to quantify the uncertainty in decarbonization of ASP flooding EOR process, the global sensitivity analysis was performed using Sobol's method. Finally, from these studies, efficient operational strategies were proposed to make the ASP flooding EOR process a low-carbon emissive EOR technique under uncertainty. It was observed that the ASP flooding EOR process emitted 1.95 times more CO 2 than did water flooding process for producing a barrel of oil. The present study also suggests that by using progressive cavity pumps for artificial lift systems and brackish water reverse osmosis water treatment technique can reduce about 24% of total CO 2 emissions during the ASP flooding EOR process. Moreover, it was also estimated that the manufacturing of alkali, surfactant, and polymer chemicals alone contributed 55.3% of total CO 2 emissions during the ASP slug injection stage. From the scenario analysis, it was found that the ASP chemical slug injection stage caused more uncertainty in estimation of CO 2 emissions and hydrogen requirement for decarbonization.