Abstract: The permeability of porous material is an important physical parameter that affects the exploitation of natural gas hydrate. In order to study the effect of natural gas hydrate on the permeability of the hydrate deposition, this paper presents the laboratory tests of fine-grained soil samples containing natural gas hydrate. The gradation of the fine-grained soils contained tetrahydrofuran hydrate was similar to the grain size distribution of soils in in Shenhu area of the South China Sea. Then, the permeability of fine-grained soil samples with different hydrate saturations was tested based on the steady state method. The test results show that the permeability of fine-grained soil containing hydrate in this test is between 11.41 mD and 61.63 mD. As the hydrate saturation increases, the relative permeability of the hydrate containing fine-grained soil decreases significantly, mainly due to the hydrate formation that fills the pores of the sediment and reduces the porosity. In addition, hydrates may also block the porous fluid seepage, thereby reducing the permeability. The test results were compared using the existing permeability model, and it was found that the result was close to the Masuda Model (N=3).

Key words: Fine Grained Soil with Natural Gas Hydrate, Tetrahydrofuran Hydrate, Permeability, Degree of Saturation, Model