Stable (001) surface of structure H (SH) natural gas hydrate was obtained with molecular dynamics simulation. The effect of three kinetic inhibitors on the surface at 277 K was investigated systematically, showing that the hydrogen bonding was formed clearly between oxygen of inhibitor and the water molecule of the hydrate surface, and the original stable structure destroyed. The clathrate structure of hydrate was, therefore, collapsed. Comparing the effects of three types of kinetic inhibitors compounds on the surface of SH hydrate, the result was found to be: PVCap＞PEO＞PVP. Further simulations reveal that the effect of PVCap on structure I (SI), structure II (SII) and SH hydrate was: SH＞SI＞SII.

Key words: natural gas hydrate, molecular dynamics simulation, inhibitor, steady surface