A physical model of multi-layer hydrate reservoir contained free gas was established for gas hydrate reservoir at W17 site in Shenhu area of South China Sea, and the effects of multi-vertical well patterns and inter-well distance on the production characteristics of hydrate reservoir by depressurization were investigated by numerical simulation. The results indicated that the production is affected by inter-well interference. The cumulative amount of dissociated gas and gas production for each well in multi-vertical well patterns are always less than that in single well alone after 36 days. For the hydrate produced by multi-vertical well patterns, the cumulative amount of water for each well can be effectively reduced compared to that by single well alone. From the percentage of hydrate dissociation and gas liquid ratio RGW perspectives, the 40 m well distance is more conducive to the exploitation of the hydrate reservoir.
Keywords hydrate, multi-vertical well patterns, South China Sea, depressurization, inter-well interference, well distance