Effect of Water Permeability Reduction Index on Gas Production from Hydrate-bearing Clayey-Silt Sediments by Depressurization

Abstract

Gas hydrates in Shenhu area are mainly hosted in clayey-silt sediments, which will make its multiphase flow more complex. Therefore, they will have an impact on gas production from hydrate-bearing clayey-silt sediments. In this study, a two-dimensional model was used to evaluate the behavior of hydrate production by depressurization in site SH2, Shenhu area, with different values of water permeability reduction index n. The results show that with the increase of n, the water production and gas production have decreased significantly. When n increases from 2.5 to 4.5, V G drops from 1.93 × 10 6 m 3 to 1.34 × 10 6 m 3 , and V W drops from 6.69 × 10 5 m 3 to 4.46 × 10 5 m 3 .