Experiments of physical modeling for petrophysical properties of natural gas hydrate

Based on three kinds of micro models( suspended, grain contact and cements) of hydrate sediments, we made synthetic samples of weak cementation and high porosity in unconsolidated sediments and a 3-D physical model of grains of which sizes vary gradually. With the experiments of physical modeling we study sensitivity of physical parameters of nature gas hydrate. Experiments show that the velocity of sonic waves is sensitive to pore fluid in sediments of weakly cemented or low effective pressure. As temperature decreases, cementing welds the grains, rock physical properties of the sediment change, velocity, elastic moduli and frequency increase, attenuation and V-p/V-s decrease, and seismic reflection are "blanking" in the sediment.