METHANE HYDRATE STABILITY IN SEAWATER

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