In Situ Generation of Clean Hydrogen in Gas Reservoirs: Experimental and Numerical Study

There has been a growing trend in the energy sector toward hydrogen generation due to the market’s rising need for hydrogen. This change has led to a larger emphasis on creating methods and tools for subsurface hydrogen production from hydrocarbons. This research determines the features of the process of In-situ Hydrogen Generation (ISHG) and interprets the results of laboratory tests to build a scheme of kinetic reactions.

A combustion tube experiment of methane combustion in porous media was conducted to reproduce the process of hydrogen synthesis from methane under reservoir conditions (high pressure and temperatures) created by the In-situ Combustion (ISC) technology. Further numerical modelling allows validating the kinetic model typical for methane combustion in a pores medium, removing uncertainties and determining the favorable conditions for hydrogen generation (temperature, steam-methane ratio, injection rate).

During numerical simulation, good convergence of numerical simulation results with experimental data was obtained, namely the temperature profile, cumulative gas production, and molar concentrations of gas components such as H₂, CH4, CO and CO₂, as the main indicators of the kinetic model adaptation quality. The methane steam reforming and methane cracking reactions demonstrated the highest contribution to producing gases. The constructed kinetic model was history-matched to the experiment of the combustion tube to assess the advancement of the high-temperature front, the transformations occurring in a given zone of elevated temperatures and the adaptation of the curves of relative-phase characteristics for the subsequent assessment of the method’s effectiveness. The obtained kinetic model and relative permeability curves were used in field-scale modelling. The up-scaled field model considered a few development strategies using existing infrastructure to optimize the hydrogen generation yield.

This paper determines the features of the process of ISHG and interprets the laboratory test results to build a scheme of kinetic reactions. The obtained kinetic model was used further in a field-scale model to assess the feasibility of hydrogen generation using existing infrastructure.