ELECTRICITY RESISTIVITY MEASUREMENT OF DISSEMINATED GAS HYDRATE BEARING SEDIMENTS UNDER CYCLIC TEMPERATURE

We have conducted a laboratory experiment to measure the electrical properties of fully saturated sediments by synthesized methane hydrate under cyclic temperature. In the cyclic temperature testing, the electricity resistivity was used to detect the secondary formation of hydrate or ice. The experiment indicated that temperature cycling may accelerate the accumulation of disseminated hydrate in the pore space of sediments. After several temperature cycles, most of free water in the pore space of sediments transferred into the gas hydrate, and the electrical resistivity of sediments containing gas hydrate increased from 3.6 ohm·m to 12 ohm·m at 1.2 ℃, when the hydrate saturation increased from 13.1% to 78.2%. It is inferred that electrical properties can be used to detect pore-filling hydrate in ocean sediments.