Integrating In-Well Hydrogen Production and CO2 Utilization Through In Situ Combustion Gasification From a Field-Scale System

Abstract This study investigates numerically the field scale application of in-situ combustion gasification (ISCG) for hydrogen production while simultaneously enhancing oil recovery and CO2 utilization. The numerical model was developed using cmg-stars and implemented on a field scale Cartesian grid, with one injection and one production well. The fluid system includes heavy oil with an average saturation of 55% and water saturation of 38%, making it suitable for ISCG and enhanced oil recovery processes. Twelve different injection scenarios were analyzed, varying oxidizer compositions (O2/N2 and O2/CO2 mixtures) and water injection rates to optimize hydrogen production, syngas production, and CO2 utilization. The results indicate that higher oxygen concentrations and CO2-based oxidizers significantly enhance hydrogen production compared to N2-based oxidizers. The study further demonstrates that moderate water injection enhances hydrogen production through the water gas shift reaction, whereas excessive water injection suppresses syngas formation due to heat loss. A technoeconomic feasibility study of ISCG using two O2/CO2 injection scenarios over certain duration was carried out. The study highlights the contrasting economic and environmental outcomes of the two injection scenarios.