Simultaneous determination of thermal conductivity, thermal diffusivity and specific heat in sI methane hydrate

Abstract

S U M M A R YThermal conductivity, thermal diffusivity and specific heat of sI methane hydrate were measured as functions of temperature and pressure using a needle probe technique. The temperature dependence was measured between −20 • C and 17 • C at 31.5 MPa. The pressure dependence was measured between 31.5 and 102 MPa at 14.4 • C. Only weak temperature and pressure dependencies were observed. Methane hydrate thermal conductivity differs from that of water by less than 10 per cent, too little to provide a sensitive measure of hydrate content in watersaturated systems. Thermal diffusivity of methane hydrate is more than twice that of water, however, and its specific heat is about half that of water. Thus, when drilling into or through hydrate-rich sediment, heat from the borehole can raise the formation temperature more than 20 per cent faster than if the formation's pore space contains only water. Thermal properties of methane hydrate should be considered in safety and economic assessments of hydrate-bearing sediment.

Heat Transfer Related to Gas Hydrate Formation/Dissociation

“…With respect to temperature effect, many studies found that hydrates exhibit a glass-like temperature dependence of thermal conductivity (Andersson and Ross, 1983;Handa and Cook, 1987;Krivchikov et al, 2005Krivchikov et al, , 2006Ross et al, 1981;Ross and Andersson, 1982;Tse and White, 1988). Among these studies, the works of Krivchikov et al (2005Krivchikov et al ( , 2006 are interesting as they found that both methane and xenon hydrates show crystal-like temperature dependence below 90 K, while exhibiting glass-like behavior above 90 K. The effect of pressure has also been investigated by many groups (Andersson and Ross, 1983;Rosenbaum et al, 2007;Waite et al, 2007). Only weak pressure dependency was observed by them.…”

“…Regarding to measurement technique, the most widely adopted ones are standard needle probe technique and transient plane source (TPS) technique (Gustafsson et al, 1979(Gustafsson et al, , 1986. For example, thermal conductivity of methane hydrate has been determined by deMartin (2001), Krivchikov et al (2005), and Waite et al (2007) using the needle probe technique. With same technique, thermal conductivities of several other gas hydrates, such as tetrohydrofuran (THF) hydrate (Cortes et al, 2009), xenon hydrate (Krivchikov et al, 2006), HCFC-141b hydrate , and CFC-11 hydrate ) have been measured.…”

Advances in Study of Mechanical Properties of Gas Hydrate-Bearing Sediments

“…As shown in Table, the thermal conductivities of methane hydrate and water differ by <10% at the temperatures found in hydrate-bearing sediments [48,49]. For this reason, firstorder thermal conductivity estimates can neglect the presence of methane hydrate and assume the sediment pore space contains only water [50].…”

EROI for the production of methane from hydrates by hot water injection

“… When we discretize in space and in time eqn (9) becomes: (10) 4) The new temperature at each point is determined in accordance with the enthalpy diagram of Figure 4 The values used for the different material properties taken from Gupta et al [10] and Waite et al [11] are: for methane hydrates: latent heat=438540 (joules/kg), specific heat=2108 joules/(kg K), density=913 kg/(m 3 ), and thermal conductivity=0.5 watts/(m.K) for water: specific heat=4187 joules/(kg.K), density=1000 kg/(m 3 ), and thermal conductivity=0.58 watts/(m.K)…”