Earth’s Cryosphere, 2018, Vol. XXII, No. 1, p. 41-45
DISSOCIATION OF GAS HYDRATES IN FROZEN SANDS: EFFECT ON GAS
E.M. Chuvilin1,2, S.I. Grebenkin1
1 Lomonosov Moscow State University, Faculty of Geology, 1, Leninskie Gory, Moscow, 119991, Russia
2 Skolkovo Institute of Science and Technology, build. 3, Skolkovo Innovation Center, Moscow, 143026, Russia; chuviline@msn.com
Special experiments have been carried out to assess gas permeability variations associated with dissociation of pore hydrate in frozen sand samples at negative temperatures. The experiments were run on an originally designed system using frozen samples artificially saturated with methane hydrate which either remained stable or dissociated upon pressure drop. The measurements under different pressures and temperatures showed that the sand samples became more permeable to gas as pore hydrate dissociated at a pressure below equilibrium (0.1 MPa) and temperatures of –5 to –3 °C. The magnitude of the gas permeability increase varied depending on initial hydrate and ice saturation of the samples.
Gas permeability, frozen sand, gas hydrate, hydrate saturation, dissociation of gas hydrate, self-preservation