Sensitivity of methane hydrate phase equilibria to sediment pore size

Hydrate equilibria experiments were conducted in Adriatic sandstone of average pore radius 550 A. The hydrate equilibria in these experiments were indistinguishable from bulk hydrate equilibria data. A sensitivity calculation of methane hydrate equilibrium shifts in porous media was conducted using the Kelvin-Clapeyron equation. The calculation indicates that no shift is discernible from equilibria in pores larger than about 600 A with thermocouple error of +/- 0.5 K. The interfacial energy used in the sensitivity calculations is that between water and hydrate. Nucleation phenomena can be applied to explain the appropriateness of this interfacial energy with the Kelvin-Clapeyron equation. (c) 2004 Elsevier B.V. All rights reserved.