scholarly journals MATHEMATICAL MODELING OF HEATED GAS DISSOCIATION PROCESS INTO THE RESERVOIR SATURATED WITH METHANE AND ITS HYDRATE

2018 ◽  
pp. 68-74
Author(s):  
N. G. Musakaev ◽  
S. L. Borodin ◽  
D. S. Belskikh
Keyword(s):  
Mathematical Modeling ◽  
Porous Medium ◽  
Gas Hydrate ◽  
Dissociation Process ◽  
Hydrate Dissociation

The article presents the mathematical modeling of heated gas dissociation process into the reservoir saturated with methane and its hydrate. We studied how different factors has affected the dissociation process. The article shows that the gas hydrate dissociation in porous medium originates on a frontal border during the injection of heated gas.

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.

Hydrate reformation characteristics in natural gas hydrate dissociation process: A review

2019 ◽  
Vol 256 ◽  
pp. 113878 ◽  
Author(s):  
Mingjun Yang ◽  
Jie Zhao ◽  
Jia-nan Zheng ◽  
Yongchen Song
Keyword(s):  
Natural Gas ◽  
Gas Hydrate ◽  
Natural Gas Hydrate ◽  
Dissociation Process ◽  
Hydrate Dissociation

Review of natural gas hydrate dissociation effects on seabed stability

2021 ◽  
Author(s):  
Min Zhang ◽  
Ming Niu ◽  
Shiwei Shen ◽  
Shulin Dai ◽  
Yan Xu
Keyword(s):  
Natural Gas ◽  
Gas Hydrate ◽  
Natural Gas Hydrate ◽  
Hydrate Dissociation

Molecular Dynamics Simulation Study of Lecithin Inhibiting Hydrate-Dissociation

2017 ◽  
Vol 890 ◽  
pp. 252-259
Author(s):  
Le Wang ◽  
Guan Cheng Jiang ◽  
Xin Lin ◽  
Xian Min Zhang ◽  
Qi Hui Jiang
Keyword(s):  
Molecular Dynamics ◽  
Water Movement ◽  
Simulation Analysis ◽  
Mass Density ◽  
Dynamics Simulation ◽  
Dissociation Process ◽  
Hydrate Dissociation ◽  
Hydrocarbon Chains ◽  
Dynamics Simulations ◽  
Mass Density Profile

Molecular dynamics simulations are used to study the dissociation inhibiting mechanism of lecithin for structure I hydrates. Adsorption characteristics of lecithin and PVP (poly (N-vinylpyrrolidine)) on the hydrate surfaces were performed in the NVT ensemble at temperatures of 277K and the hydrate dissociation process were simulated in the NPT ensemble at same temperature. The results show that hydrate surfaces with lecithin is more stable than the ones with PVP for the lower potential energy. The conformation of lecithin changes constantly after the balanced state is reached while the PVP molecular dose not. Lecithin molecule has interaction with lecithin nearby and hydrocarbon-chains of lecithin molecules will form a network to prevent the diffusion of water and methane molecules, which will narrow the available space for hydrate methane and water movement. Compared with PVP-hydrate simulation, analysis results (snapshots and mass density profile) of the dissociation simulations show that lecithin-hydrate dissociates more slowly.

Improving the Accuracy of Gas Hydrate Dissociation Point Measurements

2006 ◽  
Vol 912 (1) ◽  
pp. 924-931 ◽  
Author(s):  
B. TOHIDI ◽  
R. W. BURGASS ◽  
A. DANESH ◽  
K. K. ØSTERGAARD ◽  
A. C. TODD
Keyword(s):  
Gas Hydrate ◽  
Hydrate Dissociation

Simulation of Arctic Gas Hydrate Dissociation in Response to Climate Change: Basin-Scale Assessment

2011 ◽  
Author(s):  
Matthew T. Reagan ◽  
George J. Moridis ◽  
Scott M. Elliott ◽  
Mathew Maltrud
Keyword(s):  
Climate Change ◽  
Gas Hydrate ◽  
Hydrate Dissociation ◽  
Scale Assessment ◽  
Basin Scale
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