ESTIMATE OF THE SORBED WATER CONTENT DURING THE GAS HYDRATE DECOMPOSITION IN PARTIALLY SATURATED SANDSTONE BASED ON THE ANALYSIS OF NUCLEAR RELAXATION TIME SPECTRA
M.Y. Shumskayte1, T.A. Yanushenko1, V.G. Smirnov2, N.A. Golikov1
1Trofimuk Institute of petroleum geology and geophysics SB RAS, 630090, Novosibirsk, Koptug ave., 3, Russia
2Nikolaev Institute of inorganic chemistry SB RAS, 630090, Novosibirsk, Lavrentiev ave., 3, Russia
Keywords: Gas hydrate, sorbed water, nuclear magnetic resonance, longitude and transverse relaxation times
Abstract
This study is developed to estimate the proportion of sorbed water converted to ice and hydrate during the interaction of wet sand samples with methane by NMR relaxometry method. It was demonstrated that a thin film of tightly bound water exists in small pores at the rock-fluid interface. This water does not freeze at the subzero temperatures achieved during the experiment; its quantity remains constant, regardless of the sample's water content. The amount of tightly bound water, as well as the amount of water converted to ice and hydrate, was calculated for all samples. Based on the known hydrate stoichiometry, the amount of methane converted to hydrate was calculated. Based on the obtained data, the optimal water content in the sample was determined, which would result in the greatest amount of hydrate formation.
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