Thermal Properties of Methane Hydrate by Experiment and Modeling and Impacts Upon Technology

Abstract

Thermal properties of pure methane hydrate, under conditions similar to naturally occurring hydrate-bearing sediments being considered for potential production, have been determined both by a new experimental technique and by advanced molecular dynamics simulation (MDS). A novel single-sided, Transient Plane Source (TPS) technique has been developed and used to measure thermal conductivity and thermal diffusivity values of low-porosity methane hydrate formed in the laboratory. The experimental thermal conductivity data are closely matched by results from an equilibrium MDS method using in-plane polarization of the water molecules. MDS was also performed using a non-equilibrium model with a fully polarizable force field for water. The calculated thermal conductivity values from this latter approach were similar to the experimental data. The impact of thermal conductivity on gas production from a hydrate-bearing reservoir was also evaluated using the Tough+/Hydrate reservoir simulator.

Dynamic simulations of potential methane release from East Siberian continental slope sediments

“…Subsequently, for each sediment column, a preliminary depth for the base of the GHSZ (BGHSZ) was calculated, and a vertical distribution of gas hydrates was introduced within the stability zone. Because the thermal conductivity of gas hydrates is slightly higher than that of seawater [Waite et al, 2007;Warzinski et al, 2008;Cortes et al, 2009], the bulk thermal conductivity of sediment changes when gas hydrates are introduced, and the BGHSZ deepens. The adjusted BGHSZ depends on the prescribed gas hydrate saturation.…”

Deep Ocean Sediment–Hydrate Relationships

“…However, within the temperature range of interest in seafloor hydrate zones, thermal conductivity changes of hydrates in a practical sense are minimal (Warzinski et al, 2008). However, within the temperature range of interest in seafloor hydrate zones, thermal conductivity changes of hydrates in a practical sense are minimal (Warzinski et al, 2008).…”

“…Methane hydrates prepared in the laboratory vary in measured thermal conductivities as a consequence of differences in preparation methods, interstitial water contents, porosities, and measurement techniques (Warzinski et al, 2008). Methane hydrates prepared in the laboratory vary in measured thermal conductivities as a consequence of differences in preparation methods, interstitial water contents, porosities, and measurement techniques (Warzinski et al, 2008).…”

Producing Methane from Offshore Hydrates

“…Simulations have evaluated impact of reservoir thermal conductivity on DM production (Warzinski et al, 2008). Conditions established for the Warzinski simulations are straightforward: constant boundary temperatures, no free gas or aquifer beneath the reservoir, impermeable overburden, and impermeable underlying boundaries.…”