Using hybrid pore scale imaging/modelling and Minkowski functionals to assess the similarity of imbibition relative permeability for hydrogen, methane and nitrogen

Reservoir simulations to assess the feasibility of underground storage of hydrogen require hydrogen-brine relative permeability as input parameter. A central question is whether hydrogen relative permeability is significantly different than other gases such as methane or nitrogen, for which relative permeability data is more available/accessible. Here we present a novel hybrid workflow combining time-resolved in-situ pore scale imaging of hydrogen/brine flow experiments with numerical Stokes flow simulations conducted on the respective pore scale fluid distributions. The advantage is a much wider accessible mobile saturation range compared to conventional methods and a more robust estimate of uncertainty ranges. The similarity in the relative permeability of the three gases is established on the basis of Corey exponents and Minkowski functionals computed from the respective pore scale fluid configurations. Results do not support the view that hydrogen has different effective wetting properties than nitrogen and methane. • A novel method for determining hydrogen relative permeability is presented. • Imbibition relative permeability shows no significant differences for hydrogen, nitrogen and methane. • This finding is supported by Minkowski functionals of the pore scale fluid configuration of the three gasses.