A Compilation of Losses Related to Hydrogen Storage in Porous Media: Implications for Hydrogen Recovery and Productivity from Saline Aquifers

This study presents a detailed compilation of hydrogen losses in porous media from various literature. In addition, it models the expected recovery factors and productivity indices in three types of geological water-bearing formations – shallow reservoirs with normal geothermal gradients, shallow reservoirs with high geothermal gradients, and deep saline aquifers. The study considers and applies the estimated losses reported in the literature to 30-day, 90-day, and 180-day storage cycles.The findings show that hydrogen recovery from water-bearing formations when potential losses are accounted for could range from 13% to 83% for both sandstone and carbonate reservoirs. This also depends on the storage cycle duration and the type of aquifer. Deep saline aquifers have larger hydrogen recovery factors for all cycles but have smaller productivity indices compared to shallow reservoirs. When maximum possible losses are considered, deep saline aquifers have better productivity indices beyond 150-day storage cycles. Reservoirs with large geothermal gradients and temperatures exceeding 120 °C are okay for hydrogen storage as long as there is sufficient cushion gas. Such reservoirs show great potential for larger hydrogen recovery and productivity indices if long-duration storage (>180 days) is required. Mineralogy was not as significant as depth, temperature, and salinity in contributing to hydrogen losses.