Hydrogen Storage Optimization in the T Gas Field Numerical Simulation Insights from the Ordos Basin

DOI: 10.14800/IOGR.1370

Abstract

Amidst the global acceleration of the energy transition and the widespread adoption of renewable energy, hydrogen has emerged as a cornerstone of future energy systems, owing to its zero-carbon emissions and high energy density. Nevertheless, the pursuit of efficient large-scale hydrogen storage persists as a formidable challenge. This research employs numerical simulations to comprehensively analyze underground hydrogen storage (UHS) in the depleted T gas field within the Ordos Basin, China. A detailed geological model and a PVT (Pressure-Volume-Temperature) fluid model encompassing hydrogen, methane, and other gases were meticulously developed. The study systematically investigated multiple factors, including hydrogen injection timing, injection rate, injection-production cycles, buffer gas type, and molecular diffusion, to assess their effects on hydrogen storage and recovery. The findings confirm that depleted gas reservoirs are highly suitable for ultra-high- pressure hydrogen storage, with a remarkable hydrogen recovery rate reaching 92.15%. It was emphasized that residual gas saturation (linked to injection timing) and buffer gas type significantly influence hydrogen purity and the ultimate recovery rate. Nitrogen, when used as a buffer gas, can enhance hydrogen recovery. Additionally, molecular diffusion was found to cause a 3.3% reduction in hydrogen recovery at lower injection rates. The research also revealed that although higher injection rates may lead to a decrease in hydrogen recovery, the number of injection-production cycles has a negligible impact on recovery performance. This in-depth exploration of ultra-high-pressure hydrogen storage in depleted gas fields identifies key variables and offers valuable insights for optimizing the deployment and operational efficiency of this technology.