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 analysed, 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 a certain duration was carried out. The study highlights the contrasting economic and environmental outcomes of the two injection scenarios.