CO2 clathrate formation and its properties in the simulated deep ocean

Nishikawa, Nobuyuki; Morishita, Masao; Uchiyama, Motoshi; Yamaguchi, Fumihiko; Ohtsubo, Kiyohito; Kimuro, Harumi; Hiraoka, Ryuzo

doi:10.1016/0196-8904(92)90068-8

Cited by 33 publications

(16 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Larson (1959, Vlahakis et al (1972 and Bozzo et al (1975) studied the effect of electrolytes on the carbon dioxide hydrate equilibrium. (1991), Saji et al (1992) and by Nishikawa et al (1992). (1991), Saji et al (1992) and by Nishikawa et al (1992).…”

mentioning

confidence: 95%

See 1 more Smart Citation

Phase equilibrium data on carbon dioxide hydrate in the presence of electrolytes, water soluble polymers and montmorillonite

1994

View full text Add to dashboard Cite

Equilibrium formation conditions for carbon dioxide hydrate were measured in pure water and in aqueous polymer and electrolyte solutions. The solutions that were used include: polyethylene oxide, partially (10 and 90 percent) hydrolyzed polyacrylamide, sodium chloride and calcium chloride. Experiments with solutions containing both electrolyte and polymers were also performed. It was found that the electrolytes exhibited a substantial inhibiting effect whereas the polymers only slightly altered the equilibrium hydrate formation conditions. The measured equilibrium formation pressures were compared with the predictions from existing hydrate equilibria methods and were found to be in good agreement. The effect of montmorillonite was also studied and it was found that it did not affect the equilibrium hydrate formation conditions.

show abstract

mentioning

confidence: 95%

“…Experimental data on hydrate formation conditions in salt solutions were also recently presented by Dholabhai et a]. (1991), Saji et al (1992) and by Nishikawa et al (1992). Englezos (1992a) presented a thermodynamics based method for the prediction of the equilibrium formation conditions in aqueous electrolyte solutions.…”

mentioning

confidence: 99%

Phase equilibrium data on carbon dioxide hydrate in the presence of electrolytes, water soluble polymers and montmorillonite

1994

View full text Add to dashboard Cite

show abstract

“…Main methods applied to dissociate MH are as follows [1,21]: i) depressurizing MH reservoirs under the equilibrium pressure [22][23][24][25][26]; ii) thermally stimulating the reservoirs by increasing the MH temperature beyond its equilibrium [27][28][29]; iii) coupling depressurization with thermal stimulation, an approach reported to be more efficient than one of the above methods alone [30][31][32]; iv) injecting inhibitors, such as methanol to induce instability in MH [33][34][35]; and v) replacing methane by CO2 in MH reservoirs [36][37][38][39][40][41].…”

Section: Introductionmentioning

confidence: 99%

Analytical investigation of gas production from methane hydrates and the associated heat and mass transfer upon thermal stimulation employing a coaxial wellbore

Roostaie

Leonenko

2020

Energy Conversion and Management

View full text Add to dashboard Cite

In this study, a radial 2D analytical approach has been developed to couple the wellbore heating process and the associated methane hydrate dissociation in the reservoir. A coaxial wellbore is assumed as the heat source where both conduction and convection heat transfers are considered. It consists of an inner tube and an outer structure of casing, gravel, and cement layers. In the reservoir, a similarity solution employing a moving boundary separating the dissociated and undissociated zones is employed to build the analytical solution. Two different operating schemes for water supply into wellbore heat source have been studied: i) from the inner tube; and ii) from the annulus section of the wellbore. Temperature distribution along the wellbore, temperature and pressure distributions in the reservoir, hydrate dissociation rate, and energy efficiency considering various initial and boundary conditions and reservoir properties are evaluated. The two different operating schemes have almost the same results with slightly higher gas production in the case of hot water entry into annulus, which is in direct contact with the reservoir. Increasing the inlet water temperature or decreasing the wellbore pressure increases gas production. Applying them simultaneously results in a greater gas production and energy efficiency. Some of the reservoir's properties, such as porosity, thermal diffusivity, thermal conductivity, and reservoir thickness, have direct relation with the dissociation rate, but the reservoir's permeability and gas viscosity have almost no impact on the process. The wellbore parameters, such as flow rate of hot water, inlet temperature, and wellbore radius except the inner tube radius, have direct impact on the wellbore mean temperature and the associated results in the dissociation process.

show abstract

“…Considering that the entrapped gas and water are bonded through physical interaction in MH, which is weaker than the chemical interactions, any change in MH equilibrium temperature or pressure would easily induce MH instability and dissociation. Main methods of MH dissociation that have been reported so far are as follows [1,7]: i) thermal stimulation by increasing the temperature of the reservoir above the equilibrium temperature [8,9]; ii) depressurization by decreasing the pressure inside the MH reservoir below the equilibrium pressure of the hydrate [10,11]; iii) depressurization in conjunction with thermal stimulation that is reported to have a better efficiency compared to the two previous methods [12]; iv) inhibitor injection by injecting fluids, such as methanol, that will induce instability of the MH formation [13,14]; and v) replacement of methane by CO2 in MH reservoirs, which also helps global warming and climate change mitigations [15][16][17][18][19]. Despite several findings regarding the hydrate dissociation methods, further investigation is required to shed more light on the potential of different methods and their aspects.…”

Section: Introductionmentioning

confidence: 99%

Gas production from methane hydrates upon thermal stimulation; an analytical study employing radial coordinates

Roostaie

Leonenko

2020

Energy

View full text Add to dashboard Cite

In this study, a radial analytical model for methane hydrate dissociation upon thermal stimulation in porous media considering the effect of wellbore structure has been developed. The analytical approach is based on a similarity solution employing a moving boundary separating the dissociated and undissociated zones. Two different heat sources are considered: i) line heat source; and ii) wellbore heat source with specific thickness consisting of casing, gravel, and cement. The temperature and pressure distributions, dissociation rate, and energy efficiency considering various initial and boundary conditions, and reservoir properties are investigated. Direct heat transfer from the heat source to the reservoir without considering the heat conduction in the wellbore thickness causes higher the dissociation rate and gas production in the line heat source model compared to the wellbore heating model. Increasing the heat source temperature or decreasing its pressure increases gas production. However, employing them simultaneously results in greater gas production but reduces energy efficiency. The dissociation rate has direct relation with porosity, thermal diffusivities, and thermal conductivities of the reservoir, but is not dependent on the reservoir's permeability.

show abstract

CO2 clathrate formation and its properties in the simulated deep ocean

Cited by 33 publications

References 0 publications

Phase equilibrium data on carbon dioxide hydrate in the presence of electrolytes, water soluble polymers and montmorillonite

Phase equilibrium data on carbon dioxide hydrate in the presence of electrolytes, water soluble polymers and montmorillonite

Analytical investigation of gas production from methane hydrates and the associated heat and mass transfer upon thermal stimulation employing a coaxial wellbore

Gas production from methane hydrates upon thermal stimulation; an analytical study employing radial coordinates

Contact Info

Product

Resources

About