The low permeability of silty hydrate reservoirs in the South China Sea is a big challenge for commercial production. Due to the advantage of integration, the multi-well pattern may be an alternative for enhancing gas recovery from these reservoirs. Here, the vertical and horizontal well patterns are designed to predict the production behaviors, and the effect of well spacing and its optimization are also carried out. The simulation results show that the long-term gas production from the formation with an ultra-low permeability will gradually decrease with an increase in well spacing while the opposite phenomenon will be observed with an increase in the formation permeability. Meanwhile, the gas-to-water ratio is not significantly affected by well spacing. The optimal well spacing can be determined by the position of the minimum curvature radius of the fitting exponential model. In addition, for the reservoir with a relatively higher permeability and the ultra-low permeability burdens, the gas recovery and gas-to-water ratio will significantly increase in two well patterns within a certain well spacing, but this stimulation may gradually weaken with the extension of production cycle. The ideal well spacing can be recommended by the relative magnitudes of cumulative gas recovery during different production periods.
 

Gas hydrate, Production enhancement, Well pattern, Silty reservoir