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

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.