Thermal Properties of a Supercooled Synthetic Sand–Water–Gas–Methane Hydrate Sample

Muraoka, Michihiro; Susuki, Naoko; Yamaguchi, Hiroko; Tsuji, T.; Yamamoto, Yoshitaka

doi:10.1021/ef502350n

Cited by 16 publications

(17 citation statements)

References 29 publications

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“…At gas saturation S h within 45%, thermal conductivity does not change (Figure 7), as reported previously [42][43][44]. The variations become notable when hydrates occupy more than 45% of the pore space.…”

Section: Hydrate Formation At T > 0°csupporting

confidence: 86%

“…New experimental data on thermal conductivity of natural gas hydrate-bearing sediments from the Nankai Trough published a few years ago were used to predict thermal conductivity from the known particle size distribution, porosity, and hydrate saturation [43]. The most successful prediction for natural sediments with hydrate saturation within 14% was achieved with a model of Effect of Ice and Hydrate Formation on Thermal Conductivity of Sediments http://dx.doi.org/10.5772/intechopen.75383 complex distribution (geometric mean), but the proposed equations were poorly applicable to sediment samples containing greater percentages of hydrates (up to 30%) [44]. This is because hydrate-bearing sediments are actually complex systems and their thermal conductivity is not a sum of values for the system constituents but rather depends on the pore space structure.…”

Section: Thermal Conductivity Of Gas Hydrate-bearing Sediments and Hydrate-accumulation Effectmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Ice and Hydrate Formation on Thermal Conductivity of Sediments

Chuvilin¹,

Bukhanov²,

Cheverev³

et al. 2018

Impact of Thermal Conductivity on Energy Technologies

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Thermal conductivity of ice-and hydrate-bearing fine-grained porous sediments (soils) has multiple controls: mineralogy, particle size, and physical properties of soil matrix; type, saturation, thermal state, and salinity of pore fluids; and pressure and temperature. Experiments show that sediments generally increase in thermal conductivity upon freezing. The increase is primarily due to fourfold difference between thermal conductivity of ice and water (~2.23 against ~0.6 W/(m•K)) and is controlled by physicochemical processes in freezing sediments. Thermal conductivity of frozen soils mainly depends on lithology, salinity, organic matter content, and absolute negative temperature, which affect the amount of residual liquid phase (unfrozen water). It commonly decreases as soil contains more unfrozen water, in the fining series 'fine sand -silty sand -sandy clay -clay', as well as at increasing temperatures, salinity, or organic carbon contents. According to experimental evidence, the behavior of thermal conductivity in hydrate-bearing sediments strongly depends on conditions of pore hydrate formation. It is higher when pore hydrates form at positive temperatures (t > 0 о C) than in the case of hydrate formation in frozen samples. Freezing and thawing of hydrate-bearing sediments above the equilibrium pressure reduces their thermal conductivity due to additional hydrate formation.

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Section: Hydrate Formation At T > 0°csupporting

confidence: 86%

Section: Thermal Conductivity Of Gas Hydrate-bearing Sediments and Hydrate-accumulation Effectmentioning

confidence: 99%

Effect of Ice and Hydrate Formation on Thermal Conductivity of Sediments

Chuvilin¹,

Bukhanov²,

Cheverev³

et al. 2018

Impact of Thermal Conductivity on Energy Technologies

View full text Add to dashboard Cite

show abstract

“…2. Calculate the amount ΔM t (mol) of MH formed from t − 1 to t where R is the gas constant, P is the pressure of the methane gas, and Z t (T gas , t , P gas , t ) is the compression coefficient of methane at time t. We 9 and Sakamoto et al 11 . For this calculation, the formulas (3-7.1)-(3-7.4) of the BWR equation 13 Figure 2a shows the temperature profile that is not affected by MH melting.…”

Section: Calculation Of the Saturation Change Of The Sample 911mentioning

confidence: 99%

Protocol for Measuring the Thermal Properties of a Supercooled Synthetic Sand-water-gas-methane Hydrate Sample

Muraoka

Susuki

Yamaguchi

et al. 2016

JoVE

Self Cite

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Methane hydrates (MHs) are present in large amounts in the ocean floor and permafrost regions. Methane and hydrogen hydrates are being studied as future energy resources and energy storage media. To develop a method for gas production from natural MH-bearing sediments and hydrate-based technologies, it is imperative to understand the thermal properties of gas hydrates. The thermal properties' measurements of samples comprising sand, water, methane, and MH are difficult because the melting heat of MH may affect the measurements. To solve this problem, we performed thermal properties' measurements at supercooled conditions during MH formation. The measurement protocol, calculation method of the saturation change, and tips for thermal constants' analysis of the sample using transient plane source techniques are described here. The effect of the formation heat of MH on measurement is very small because the gas hydrate formation rate is very slow. This measurement method can be applied to the thermal properties of the gas hydrate-water-guest gas system, which contains hydrogen, CO2, and ozone hydrates, because the characteristic low formation rate of gas hydrate is not unique to MH. The key point of this method is the low rate of phase transition of the target material. Hence, this method may be applied to other materials having low phase-transition rates.

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“…These data are essential for assessing the thawing halos in permafrost horizons containing relict gas around production wells, as well as prediction of the wellbore stability during relict hydrates dissociation. Unfortunately, today there is practically no experimental data of thermal properties of gas hydrates and hydrate-bearing sediments at non-equilibrium conditions (at temperature below 0 • C), except only few publications [23,24] (because most of the publications have covered the thermal properties of gas hydrates and hydrate-contain sediments at stable conditions which are important for methane production from gas hydrates reservoirs [25][26][27][28][29][30][31][32][33][34][35]). The obtained results at non-equilibrium conditions show that the thermal conductivity of frozen hydrate-bearing sediments may change by several times during the self-preservation effect and differs from the thermal conductivity of frozen hydrate-free and hydrate-bearing soils contain stable gas hydrates [36,37].…”

Section: Introductionmentioning

confidence: 99%

Thermal Conductivity of Frozen Sediments Containing Self-Preserved Pore Gas Hydrates at Atmospheric Pressure: An Experimental Study

Chuvilin

Bukhanov

2019

Geosciences

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The paper presents the results of an experimental thermal conductivity study of frozen artificial and natural gas hydrate-bearing sediments at atmospheric pressure (0.1 MPa). Samples of hydrate-saturated sediments are highly stable and suitable for the determination of their physical properties, including thermal conductivity, due to the self-preservation of pore methane hydrate at negative temperatures. It is suggested to measure the thermal conductivity of frozen sediments containing self-preserved pore hydrates by a KD-2 needle probe which causes very little thermal impact on the samples. As shown by the special measurements of reference materials with known thermal conductivities, the values measured with the KD-2 probe are up to 20% underestimated and require the respective correction. Frozen hydrate-bearing sediments differ markedly in thermal conductivity from reference frozen samples of the same composition but free from pore hydrate. The difference depends on the physical properties of the sediments and on changes in their texture and structure associated with the self-preservation effect. Namely, it increases proportionally to the volumetric hydrate content, hydrate saturation, and the percentage of water converted to hydrate. Thermal conductivity is anisotropic in core samples of naturally frozen sediments that enclose visible ice-hydrate lenses and varies with the direction of measurements with respect to the lenses. Thermal conductivity measurements with the suggested method provide a reliable tool for detection of stable and relict gas hydrates in permafrost.

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Thermal Properties of a Supercooled Synthetic Sand–Water–Gas–Methane Hydrate Sample

Cited by 16 publications

References 29 publications

Effect of Ice and Hydrate Formation on Thermal Conductivity of Sediments

Effect of Ice and Hydrate Formation on Thermal Conductivity of Sediments

Protocol for Measuring the Thermal Properties of a Supercooled Synthetic Sand-water-gas-methane Hydrate Sample

Thermal Conductivity of Frozen Sediments Containing Self-Preserved Pore Gas Hydrates at Atmospheric Pressure: An Experimental Study

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