Veselin Mitkov1
University of Mining and Geology “St. Ivan Rilski”, Sofia, Bulgaria
Received: 05.08.2025
Accepted: 26.11.2025
https://doi.org/10.53656/nat2026-1.01
Abstract. An integrated model for determining the reservoir properties of the rock reservoir during underground storage of a gas-hydrogen mixture is presented. The methodology consists of four main modules: Characterization of the core sample (mineral composition, porosity, and permeability), determination of the parameters of the gas-hydrogen mixture at different % hydrogen and methane contents (5%, 15%, 25%), study of flow properties (porosity and permeability of the core sample at different gas-hydrogen mixture contents), and a module summarizing the results. The results obtained from the study using the developed methodology form the basis for designing the storage indicators for gas-hydrogen mixtures in underground gas storage facilities.
Keywords: hydrogen, underground storage, capacitance parameters, flow parameters


