Review of exploration and production technology of natural gas hydrate

Cui, Yudong; Lü, Cheng; Wu, Min; Peng, Yue; Yao, Yanbin; Luo, Wanjing

doi:10.26804/ager.2018.01.05

Cited by 108 publications

(48 citation statements)

References 29 publications

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“…At that, there is a high cross-flow of methane j (V 1 > V 2 ). For figure (b), the largest part of the "C" area is outside the diffusion layer (2). Thus, the area of the combustion region, which is inside the diffusion layer, is the third factor that affects combustion.…”

Section: The Dissociation Rate In the Combustion Of Methane Hydratementioning

confidence: 98%

“…Figure 5 presents experimental data (points 1) for the dissociation rate j of methane hydrate depending on the velocity of the incoming air flow U0. The calculated curve 2 is obtained in accordance with expression (2). The difference between the curve 2 and experimental data 1 can be associated with both the experimental error (measurement error j) and the deviation of the dependence q ~ (U0) 0.5 from the quadratic form.…”

Section: The Dissociation Rate In the Combustion Of Methane Hydratementioning

confidence: 98%

“…Huge deposits of natural gas in the form of methane hydrates are found in the marine sediments [1,2]. Attention to alternative clean energy sources is increasing every year.…”

Section: The Key Parameters Controlling the Dissociation Of Gas Hydratesmentioning

confidence: 99%

“…Attention to alternative clean energy sources is increasing every year. Today, scientific interest is focused on the methods of extraction of alternative raw materials, technologies for their storage, transportation, as well as methods of efficient combustion of natural fuel [1][2][3]. The complexity of the study of methane hydrates and for a large number of methane hydrate particles, water saturation occurs and water concentration in the flame is the same as on the surface of the powder layer (0.65).…”

Section: The Key Parameters Controlling the Dissociation Of Gas Hydratesmentioning

confidence: 99%

“…From the above, it follows that, to increase the efficiency of combustion of methane hydrate, the following problems must be surmounted: (1) Maintaining the powder temperature quasi-constant for the entire volume and during the entire combustion time; (2) the temperature of the powder should provide a high rate of dissociation of the methane hydrate, i.e., to exclude the phenomenon of self-preservation and at the same time to ensure the maximum deviation of temperature and pressure from the equilibrium curve (the driving forces of dissociation); (3) it is necessary to ensure the kinetic combustion condition, as the excess of oxidant and fuel lead to low reaction rates during combustion. To do this, it is necessary to accurately calculate the diffusion mixing layer and to select the optimal conditions for mixing the fuel and oxidizer; and (4) the concentration of steam that enters the combustion region should be reduced.…”

Section: The Key Parameters Controlling the Dissociation Of Gas Hydratesmentioning

confidence: 99%

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An Experimental Study of Combustion of a Methane Hydrate Layer Using Thermal Imaging and Particle Tracking Velocimetry Methods

et al. 2018

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In this paper, the combustion of methane hydrate over a powder layer is experimentally studied using thermal imaging and Particle Tracking Velocimetry (PTV) methods. The experiments are carried out at different velocities of the external laminar air-flow from zero to 0.6 m/s. Usually, simulation of methane hydrate combustion is carried out without taking into account free convection. A standard laminar boundary layer is often considered for simplification, and the temperature measurements are carried out only on the axis of the powder tank. Measurements of the powder temperature field have shown that there is a highly uneven temperature field on the layer surface, and inside the layer the transverse temperature profiles are nonlinear. The maximum temperature always corresponds to the powder near the side-walls, which is more than 10 • C higher than the average volumetric temperature in the layer. Thermal imager measurements have shown the inhomogeneous nature of combustion over the powder surface and the highly variable velocity of methane above the surface layer. The novelty of the research follows from the measurement of the velocity field using the PTV method and the measurement of methane velocity, which show that the nature of velocity at combustion is determined by the gas buoyancy rather than by the forced convection. The maximum gas velocity in the combustion region exceeds 3 m/s, and the excess of the oxidizer over the fuel leads to more than tenfold violation of the stoichiometric ratio. Despite that, the velocity profile in the combustion region is formed mainly due to free convection, it is also necessary to take into account the external flow of the forced gas U 0 . Even at low velocities U 0 , the velocity direction lines significantly deviate under the forced air-flow. combustion is associated with the presence of three interrelated processes: The dissociation of solid particles of methane hydrate; gas filtration through a multicomponent medium (methane-water-water vapor); and diffusion combustion of methane in the mixing layer (methane-air-water vapor), which is usually implemented over the powder layer. Therefore, it is necessary to consider the features of these processes.The gas hydrate dissociation rate is determined by the following driving forces: Deviation of temperature and pressure from the equilibrium states, size of particles, and structural characteristics of ice crust [4,5]. Dissociation at positive temperatures has a thin film of water formed on the surface of solid particles. The dissociation rate is quasi-constant for most of the dissociation time. The case of negative temperatures is significantly more difficult to describe due to the emergence of the phenomenon of self-preservation [6]. In the temperature range of 230-268 K, the dissociation rate of methane hydrate decreases by several orders of magnitude and strongly depends on temperature. This annealing temperature region was called the self-preservation region. The lowest dissociation rate of methane hydrate is achieved at th...

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Section: The Dissociation Rate In the Combustion Of Methane Hydratementioning

confidence: 98%

Section: The Dissociation Rate In the Combustion Of Methane Hydratementioning

confidence: 98%

“…Huge deposits of natural gas in the form of methane hydrates are found in the marine sediments [1,2]. Attention to alternative clean energy sources is increasing every year.…”

Section: The Key Parameters Controlling the Dissociation Of Gas Hydratesmentioning

confidence: 99%

Section: The Key Parameters Controlling the Dissociation Of Gas Hydratesmentioning

confidence: 99%

Section: The Key Parameters Controlling the Dissociation Of Gas Hydratesmentioning

confidence: 99%

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