METHANE HYDRATE STABILITY IN SEAWATER

Experimental data are presented for methane hydrate stability conditio ns in seawater (S almost-equal-to 33.5 part per thousand). For the pre ssure range of 2.75-10.0 MPa, at any given pressure, the dissociation temperature of methane hydrate is depressed by approximately -1.1 degr ees-C relative to the pure methane-pure water system. These experiment al results are consistent with previously reported thermodynamic predi ctions and experimental results obtained with artificial seawater. Col lectively these results provide a minimum constraint concerning depth ranges over which methane hydrate is stable in the oceanic environment .