The objective of this study is to numerically investigate system behavior of H2 or natural-gas (CH4) mixtures (HNM) in aquifer-related underground gas storage (UGS), and the effect of the gas composition and salinity on energy-recovery efficiency. The findings provide valuable insights into engineering decisions associated with the injection, production, and overall behavior of HNM in aquifer-based UGS facilities.
Introduction
Storing HNM requires careful considerations of reservoir properties, gas behavior, and operational feasibility. H2 is lighter and more buoyant than CH4, which can cause gas stratification within the reservoir. Furthermore, the low density of H2 affects reservoir pressure and gas-expansion rate, requiring greater optimization of storage strategies when compared with CH4-dominated storage.
