Mathematical modelling of injection gas hydrate formation into the massif of snow saturated the same gas

2016 ◽  
Vol 11 (2) ◽  
pp. 233-239 ◽  
Author(s):  
V.Sh. Shagapov ◽  
A.S. Chiglintseva ◽  
S.V. Belova
Keyword(s):  
Diffusion Coefficient ◽  
Mathematical Modelling ◽  
Gas Hydrate ◽  
Hydrate Formation ◽  
Influence Analysis ◽  
Hydrate Layer ◽  
Gas Hydrate Formation ◽  
Hydrate Saturation ◽  
The Given ◽  
Cold Gas

Considered the problem of gas hydrate formation during injection of cold gas in the snow massif, initially saturated with the same gas. In work some limited scheme according to which, intensity of hydrate formation is limited by diffusion of gas through the hydrate layer formed between the phases of gas and ice, to the boundary of contact ice-hydrate, and is determined by the introduction of only one parameter the given diffusion coefficient. Shows the distributions of pressure, temperature, hydrate saturation and the saturation of the snow at different points in time. Held influence analysis of the effect of the pressure of the injected gas and the permeability of the snow massif on the intensity of hydrate formation.

scholarly journals Gas hydrate in-situ formation and dissociation in clayey-silt sediments: An investigation by low-field NMR

2020 ◽  
pp. 014459872097415
Author(s):  
Xiaoxiao Sun ◽  
Xuwen Qin ◽  
Hongfeng Lu ◽  
Jingli Wang ◽  
Jianchun Xu ◽  
...  
Keyword(s):  
Gas Hydrate ◽  
Hydrate Formation ◽  
Dissociation Process ◽  
Hydrate Dissociation ◽  
Hydrate Reservoir ◽  
Low Field ◽  
Gas Hydrate Formation ◽  
Clayey Silt ◽  
Hydrate Saturation ◽  
Low Field Nmr

The hydrate reservoir in the Shenhu Area of the South China Sea is a typical clayey-silt porous media with high clay mineral content and poor cementation, in which gas hydrate formation and dissociation characteristics are unclear. In this study, the CO2 hydrate saturation, growth rate, and permeability were studied in sandstone, artificial samples, and clayey-silt sediments using a custom-built measurement apparatus based on the low-field NMR technique. Results show that the T2 spectra amplitudes decrease with the hydrate formation and increase with the dissociation process. For the artificial samples and Shenhu sediments, the CO2 hydrate occupies larger pores first and the homogeneity of the sandstone pores becomes poor. Meanwhile, compared with the clayey-silt sediments, CO2 hydrate is easier to form and with higher hydrate saturation for the sandstone and artificial samples. In hydrate dissociation process, there exists a protection mechanism, i.e. the dissociation near the center of hydrates grain is suppressed when gas pressure drops suddenly and quickly. For permeability of those samples, it decreased with hydrate forms, and increases with hydrate dissociation. Meanwhile, with the same hydrate saturation, permeability is higher in hydrate formation than in dissociation.

scholarly journals Quantifying in-situ gas hydrates at active seep sites in the eastern Black Sea using pressure coring technique

2011 ◽  
Vol 8 (3) ◽  
pp. 4529-4558 ◽  
Author(s):  
K. Heeschen ◽  
M. Haeckel ◽  
I. Klaucke ◽  
M. K. Ivanov ◽  
G. Bohrmann
Keyword(s):  
Black Sea ◽  
Gas Hydrate ◽  
Pore Volume ◽  
Sediment Cores ◽  
Stability Boundary ◽  
Hydrate Formation ◽  
Gas Hydrate Formation ◽  
Hydrate Saturation ◽  
Gas Volume

Abstract. In the eastern Black Sea, we determined methane (CH4) concentrations, gas hydrate volumes and their vertical distribution from combined gas and chloride (Cl−) measurements within pressurized sediment cores. The total gas volume collected from the cores corresponds to concentrations of 1.2–1.4 mol of methane per kg porewater at in-situ pressure, which is equivalent to a gas hydrate saturation of 15–18% of pore volume and amongst the highest values detected in shallow seep sediments. At the central seep site, a high-resolution Cl− profile resolves the upper gas hydrate stability boundary and a continuous layer of hydrates in a sediment column of 120 cm thickness. Including this information, a more precise gas hydrate saturation of 22–24% pore volume can be calculated. This is higher in comparison to a saturation calculated from the Cl− profile alone, resulting in 14.4%. The likely explanation is an active gas hydrate formation from CH4 gas ebullition. The hydrocarbons at Batumi Seep are of shallow biogenic origin (CH4 > 99.6%), at Pechori Mound they originate from deeper thermocatalytic processes as indicated by the lower ratios of C1 to C2–C3 and the presence of C5.

Features of hydrate formation in porous formations during gas blowing

2012 ◽  
Vol 9 (1) ◽  
pp. 72-75
Author(s):  
I.K. Gimaltdinov ◽  
M.K. Khasanov ◽  
M.V. Stolpovsky ◽  
S.R. Kildibaeva
Keyword(s):  
Phase Transition ◽  
Porous Medium ◽  
Porous Media ◽  
Finite Length ◽  
Gas Hydrate ◽  
Hydrate Formation ◽  
Gas Hydrate Formation ◽  
Gas Blowing ◽  
Cold Gas

Theoretically, the processes of gas hydrate formation in gases saturated with gas and water porous media of finite length when they are blown with cold gas. The influence of initial parameters of the porous medium, as well as blowdown conditions on the features of the evolution of the hydration-saturation fields and temperature. It is shown that for some parameters of the injected gas, the boundary can be stopped phase transition.

scholarly journals Quantifying in-situ gas hydrates at active seep sites in the eastern Black Sea using pressure coring technique

2011 ◽  
Vol 8 (12) ◽  
pp. 3555-3565 ◽  
Author(s):  
K. U. Heeschen ◽  
M. Haeckel ◽  
I. Klaucke ◽  
M. K. Ivanov ◽  
G. Bohrmann
Keyword(s):  
Black Sea ◽  
Gas Hydrate ◽  
Pore Volume ◽  
Sediment Cores ◽  
Hydrate Formation ◽  
Gas Hydrate Formation ◽  
Hydrate Saturation ◽  
Gas Volume ◽  
Quantifying In

Abstract. In the eastern Black Sea, we determined methane (CH4) concentrations, gas hydrate volumes, and their vertical distribution from combined gas and chloride (Cl−) measurements within pressurized sediment cores. The total gas volume collected from the cores corresponded to concentrations of 1.2–1.4 mol CH4 kg−1 porewater at in-situ pressure, which is equivalent to a gas hydrate saturation of 15–18% of pore volume and amongst the highest values detected in shallow seep sediments. At the central seep site, a high-resolution Cl− profile resolved the upper boundary of gas hydrate occurrence and a continuous layer of hydrates in a sediment column of 120 cm thickness. Including this information, a more precise gas hydrate saturation of 22–24% pore volume could be calculated. This volume was higher in comparison to a saturation calculated from the Cl− profile alone, resulting in only 14.4%. The likely explanation is an active gas hydrate formation from CH4 gas ebullition. The hydrocarbons at Batumi Seep are of shallow biogenic origin (CH4 > 99.6%), at Pechori Mound they originate from deeper thermocatalytic processes as indicated by the lower ratios of C1 to C2–C3 and the presence of C5.

Thermodynamic Modelling of Gas Hydrate Formation in the Presence of Inhibitors and the Consideration of their Effect

2014 ◽  
Vol 14 (1) ◽  
pp. 45
Author(s):  
Peyman Sabzi ◽  
Saheb Noroozi
Keyword(s):  
Gas Hydrates ◽  
Gas Hydrate ◽  
Low Temperatures ◽  
Hydrate Formation ◽  
Transportation Systems ◽  
Flow Lines ◽  
Main Approach ◽  
Efficient Inhibitor ◽  
System A ◽  
Gas Hydrate Formation

Gas hydrates formation is considered as one the greatest obstacles in gas transportation systems. Problems related to gas hydrate formation is more severe when dealing with transportation at low temperatures of deep water. In order to avoid formation of Gas hydrates, different inhibitors are used. Methanol is one of the most common and economically efficient inhibitor. Adding methanol to the flow lines, changes the thermodynamic equilibrium situation of the system. In order to predict these changes in thermodynamic behavior of the system, a series of modelings are performed using Matlab software in this paper. The main approach in this modeling is on the basis of Van der Waals and Plateau's thermodynamic approach. The obtained results of a system containing water, Methane and Methanol showed that hydrate formation pressure increases due to the increase of inhibitor amount in constant temperature and this increase is more in higher temperatures. Furthermore, these results were in harmony with the available empirical data.Keywords: Gas hydrates, thermodynamic inhibitor, modelling, pipeline blockage

scholarly journals Rapid Gas Hydrate Formation—Evaluation of Three Reactor Concepts and Feasibility Study

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3615
Author(s):  
Florian Filarsky ◽  
Julian Wieser ◽  
Heyko Juergen Schultz
Keyword(s):  
Gas Hydrates ◽  
Gas Hydrate ◽  
Hydrate Formation ◽  
Synthetic Natural Gas ◽  
Operation Conditions ◽  
Gas Hydrate Formation ◽  
Gas Conditioning ◽  
And Storage ◽  
Economic Considerations ◽  
High Storage

Gas hydrates show great potential with regard to various technical applications, such as gas conditioning, separation and storage. Hence, there has been an increased interest in applied gas hydrate research worldwide in recent years. This paper describes the development of an energetically promising, highly attractive rapid gas hydrate production process that enables the instantaneous conditioning and storage of gases in the form of solid hydrates, as an alternative to costly established processes, such as, for example, cryogenic demethanization. In the first step of the investigations, three different reactor concepts for rapid hydrate formation were evaluated. It could be shown that coupled spraying with stirring provided the fastest hydrate formation and highest gas uptakes in the hydrate phase. In the second step, extensive experimental series were executed, using various different gas compositions on the example of synthetic natural gas mixtures containing methane, ethane and propane. Methane is eliminated from the gas phase and stored in gas hydrates. The experiments were conducted under moderate conditions (8 bar(g), 9–14 °C), using tetrahydrofuran as a thermodynamic promoter in a stoichiometric concentration of 5.56 mole%. High storage capacities, formation rates and separation efficiencies were achieved at moderate operation conditions supported by rough economic considerations, successfully showing the feasibility of this innovative concept. An adapted McCabe-Thiele diagram was created to approximately determine the necessary theoretical separation stage numbers for high purity gas separation requirements.

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