A new modelling approach for in-situ hydrogen production from heavy oil reservoirs: Sensitivity analysis and process mechanisms.

The increasing demand for eco-friendly and renewable energy has positioned hydrogen as a viable solution for global energy and environmental challenges. In-situ combustion gasification of heavy oil reservoirs offers potential for large-scale hydrogen production, injecting steam and air (or alternative gases) to trigger complex chemical reactions leading to hydrogen and syngas generation. However, a research gap exists due to the lack of a comprehensive numerical model for accurately simulating hydrogen production under SARA-based (saturate, aromatic, resin, asphaltene) hydrocarbon characterization in experiments and field study. This study addresses the gap by investigating in-situ combustion gasification for hydrogen generation in heavy oil reservoirs. A novel model based on SARA characterization is proposed, showing fidelity with experimental and numerical results. Different injection strategies, like pure oxygen and CO 2 , impact hydrogen production. Oxygen injection yields less hydrogen than air injection, highlighting the importance of oxygen control. CO 2 injection reduces hydrogen but aids carbon management. The oxygen to nitrogen ratio (61/39) demonstrates the highest hydrogen-to-syngas ratio. Practical implementation requires economic feasibility, operational practicality, safety, and environmental considerations. This study advances in-situ combustion gasification technology, facilitating efficient and sustainable hydrogen generation from heavy oil reservoirs. [Display omitted] • A new modeling approach based on SARA characterization is presented. • The theoretical results are validated with the experimental and numerical studies. • Impact of temperature on hydrogen yields at different stages are evaluated. • Effects of different gas injection schemes on the hydrogen yield are investigated. • Optimal gas mix ratio maximizes hydrogen yield, favors high hydrogen-to-syngas ratio. [ABSTRACT FROM AUTHOR]