The thermal conductivity of methane hydrate was measured by means of Gustafsson's transient plane source (TPS) technique. The sample was formed from 99.9 vol % methane gas with a 0.9709 mol·m-3 aqueous sodium dodecyl sulfate (SDS) solution under 6.60 MPa and 273.15 K. The in-situ measurement was performed in the temperature range from (263.06 to 277.87) K, and the thermal conductivity of unimpacted sample was lower than that of the impacted, with values of (0.334 to 0.381) W·m-1·K-1 and (0.564 to 0.587) W·m-1·K-1, respectively. The results showed that the methane hydrate has glasslike thermal properties.

[1] Effective thermal conductivity (ETC) of both tetrahydrofuran (THF) and methane hydrate-bearing sandy porous media was measured by the Hot Disk Thermal Constant Analyser. Thermal conductivity of methane hydrate is 0.575 W m À1 K À1 at 0°C and 6.6 MPa (methane gas pressure), which is close to THF hydrate's 0.51 W m À1 K À1 at 0°C and 0.1 MPa (atmosphere pressure). However, the measured 1 W m À1 K À1 ETC of methane hydrate-bearing sand is significantly lower than that of THF hydrate-bearing sand at $2 W m À1 K À1 . This is because the methane hydrate formed with a sodium dodecyl sulfate (SDS) solution in sand at our laboratory has a ''wall creeping'' growth characteristic and consequently a large part of the pores were filled with methane free gas. ETCs of sand containing gas hydrates were also calculated using a renormalization method. The process involves sample partitioning, labeling, initial value assignments, and renormalization calculations. A Monte Carlo analysis was applied to sample laboratory-scale gas hydrate-bearing sand assemblies. We found that the renormalization modeling results agreed well with measured ETCs when each photo of a 1.3 mm  1.3 mm subsample was divided into 16 or more blocks.Citation: Huang, D., and S. Fan (2005), Measuring and modeling thermal conductivity of gas hydrate-bearing sand,

An experiment has been constructed to measure thermal conductivity of combination gas hydrate and combination gas hydrate‐sand mixtures. The combination gas hydrate formed from the combination gas (methane 90.01 volume %, ethane 5.03 volume % and propane 4.96 volume %) and 0.971 mol/m3 aqueous sodium dodecyl sulfate (SDS) solution has a thermal conductivity around 0.55 W/(m·K) from –10°C to 5°C at 6.6MPa. The hydrate's thermal conductivity shows glass‐like dependence on temperature, i.e. it has a positive slope with temperature. However, the measured 1.2 W/(m·K) effective thermal conductivity (ETC) of combination gas hydrate‐bearing sand is significantly lower than that of tetrahydrofuran (THF) hydrate‐bearing sand (about 1.9 W/(m·K). This is because the hydrate formed with a SDS solution in sand at our laboratory has a “wall creeping” growth characteristic and consequently a large part of the pores were filled with free gas. In order to obtain good‐characteristic hydrate sample for measurement, this work advances a method to promote the reaction of SDS solution and gas. When the temperature vibrates from –10°C to 4°C, it is found the stagnated reaction reacts again in the zone of phase change temperature of water. And the surviving water could be consumed away after several vibration periods. The SDS's effects to the measurement are also discussed by experiments. It's indicated that the SDS concentration used in this work has a minor effect to the hydrate's thermal conductivity, and it only causes a deviation of ±1.5%.