Natural gas diffusion model and diffusion computation in well Cai25 Bashan Group oil and gas reservoir

摘要

Natural gas diffusion through the cap rock is mainly by means of dissolving in water, so its concentration can be replaced by solubility, which varies with temperature, pressure and salinity in strata. Under certain geological conditions the maximal solubility is definite, so the diffusion computation can be handled approximately by stable state equation. Furthermore, on the basis of the restoration of the paleo-buried history, the diffusion is calculated with the dynamic method, and the result is very close to the real diffusion value in the geological history.