Experimental Study On The Impact Of Hydrates On Porous Media Permeability

The world is puzzled by energy shortage and environment deterioration. China's energy demand is increasing rapidly with its high-speed development of economy, which results in serious damage to natural ecological environment. It is a pressing task to find a way of providing clean and high effective energy due to the enormous pressure on the environment. Methane hydrate, which has characteristics of large reserves, high energy density and clean combustion, is regarded as the best energy resource with a broad prospect for further development in the 21st century. A through, in-depth and systematic study on methane hydrate has important academic and practical significances.An experiment platform is set up to simulate hydrate formation in porous media in laboratory and such experiments are carried out. The determination and control methods of hydrate saturation in porous media are studied. It turns out that the hydrate saturation generated in constant volume under laboratory conditions is related to initial pressure. A set of experimental apparatus used to measure the permeability of porous media containing methane hydrate is developed. The relationship between porosity and permeability is studied. The experiments of measuring permeability are carried out with BZ-01 and BZ-02 glass sand as porous media. Methane hydrate is generated using constant volume method. And the permeability changes of porous media are tested under different saturation of methane hydrate with distilled water as the medium. The result shows that the existence of methane hydrate in porous media can cause a sharp decline in its permeability, and saturation-permeability curve obeys exponential distribution. A fitted empirical formula of permeability changes with the saturation is obtained based on experimental data. Compared with permeability models, the experimental results are consistent with parallel capillary model in which hydrate occupies capillary center.