Phase transitions of water in gas-saturated sediments
Phase transitions of water in gas-saturated sediments (in Proceedings of the VI international conference on Gas in marine sediments, I. S. Gramberg (prefacer) and A. E. Kontorovich (prefacer))
Russian Geology and Geophysics (July 2002) 43 (7): 655-663
- aliphatic hydrocarbons
- alkanes
- clastic sediments
- clay minerals
- cooling
- density
- dissociation
- experimental studies
- gas hydrates
- grain size
- heating
- hydrocarbons
- ice
- instruments
- kaolinite
- laboratory studies
- methane
- mineral composition
- montmorillonite
- organic compounds
- P-T conditions
- petrography
- phase equilibria
- physical properties
- pore water
- porosity
- porous materials
- pressure
- sand
- sediments
- sheet silicates
- silicates
- size distribution
- stability
- temperature
- textures
- water
- water content
We have experimentally studied the peculiarities of water-gas-hydrate and water-ice phase transitions under gas pressure in dispersed methane-saturated sediments in the course of cyclic cooling-heating. Data on the conditions of hydrate and ice formation in the sediment pores have been obtained. It is shown that on cooling of dispersed rocks, only part of the pore water passes into hydrates; the rest (intimately bound with the particle surface) transforms into ice during further cooling. Hydrate formation in the studied sediments, compared with the system pure-water-gas, occurs at higher pressures and lower temperatures. It is demonstrated that the sediment dispersion and cooling-heating cycles affect the PT-conditions of formation and decomposition of gas hydrates. Petrography of frozen rocks artificially saturated in hydrates is studied.
