Numerical study on decomposition characteristics of natural gas hydrate based on molecular dynamics method

The molecular dynamics method is used to investigate decomposition characteristics of natural gas hydrate under different pressure and salinity. In this paper, the influence of pressure variation on the stability of natural gas hydrate under high pressure is studied from the molecular point of view based on the seabed pressure in Shenhu sea area. At the same time, taking the real marine conditions in the South China Sea as a reference, the effect of the synergistic effect of various salt ions on the decomposition of natural gas hydrate under the effect of salinity is studied. Its decomposition behavior is discussed by analyzing the parameters such as cell conformation, radial distribution function, mean square displacement and self-diffusion coefficient. The results show that pressure and salinity influence the decomposition of natural gas hydrate through modifying stable its conditions, from solid state to gas-liquid state. And the reduction of pressure accelerates the decomposition of natural gas hydrate under high pressure, while the increase of salinity promotes the decomposition of natural gas hydrate under the condition of high salinity.