Numerical simulation of bitumen recovery via supercritical water injection with in-situ upgrading

As the demand of crude oil is increasing along with depletion of conventional oil, unconventional oil is being extracted to meet the demand worldwide. Heavy oil is one of the largest unconventional crude oil resources, especially in Canada and Venezuela. Thermal recovery is a promising technology developed over the past decades. Particularly, steam injection is considered one of the most effective thermal recovery processes, but it is energy-intensive and is not environmentally friendly. Unlike steam injection, supercritical water flooding (SCWF) is a miscible flooding and in-situ upgrading process and has been experimentally proven as a more effective process than steam injection. However, it has not been field-proven yet. Therefore, numerical simulation is necessary to show its feasibility. In this paper, we present a numerical simulation workflow for SCWF by utilizing CMG-STARS and study its sensitive parameters based on simulation outputs. Simulation results show that SCWF has a better performance due to its gas production from aquathermolysis. Its recovery efficiency can double when compared to steam injection owing to its in-situ upgrading feature within the same production window. SCWF is more suitable in thinner, lower porosity and higher permeability reservoirs. Operational parameters are slightly influencing its reservoir performance, and the influence is negligible as long as a minimum miscible pressure (MMP) is achieved.