The application of prediction method for
diffusion behavior of underground
hydrogen in
pore scale of water-containing clay mineral belongs to the technical field of underground
hydrogen energy storage and unconventional gas migration prediction, and the key point is to fill water molecules and salt ions into the pores according to the target
water saturation and
salinity; the initial model of the water-containing clay mineral pores is pre-equilibrated by the
molecular dynamics method;
hydrogen molecules are filled under the given
temperature and pressure conditions by the grand canonical Monte Carlo method, and the
hydrogen pressure is corrected by the SRK-EOS state equation; the hydrogen
diffusion simulation is carried out by the
molecular dynamics method with temperature and fugacity as input parameters, the
mean square displacement of hydrogen in the pores is calculated, and the self-
diffusion coefficient is obtained; the application can quantitatively characterize the diffusion
rate change rule of hydrogen in the clay pores under different water film thickness,
salinity and
temperature and pressure conditions, and reveal the diffusion inflection point, diffusion inhibition stage and migration restriction mechanism caused by the water film or water bridge structure.