Study on the spatial differences of methane hydrate dissociation process by depressurization using an L-shape simulator

Energy ◽  
2021 ◽  
Vol 228 ◽  
pp. 120635
Author(s):  
Jin-Long Cui ◽  
Li-Wei Cheng ◽  
Jing-Yu Kan ◽  
Wei-Xin Pang ◽  
Jun-Nan Gu ◽  
...  
2013 ◽  
Vol 310 ◽  
pp. 28-32
Author(s):  
Jian Ye Sun ◽  
Yu Guang Ye ◽  
Chang Ling Liu ◽  
Jian Zhang

The simulate experiments of gas production from methane hydrates reservoirs was proceeded with an experimental apparatus. Especially, TDR technique was applied to represent the change of hydrate saturation in real time during gas hydrate formation and dissociation. In this paper, we discussed and explained material transformation during hydrate formation and dissociation. The hydrates form and grow on the top of the sediments where the sediments and gas connect firstly. During hydrates dissociation by depressurization, the temperatures and hydrate saturation presented variously in different locations of sediments, which shows that hydrates dissociate earlier on the surface and outer layer of the sediments than those of in inner. The regulation of hydrates dissociation is consistent with the law of decomposition kinetics. Furthermore, we investigated the depressurizing range influence on hydrate dissociation process.


Author(s):  
Xin Wang ◽  
Weizhong Li ◽  
Minghao Yu

Methane hydrate has been paid considerable attention on how to exploit it by efficient and economical methods. A computer modeling approach was used to obtain more detail information during the process of methane hydrate decomposition. A comprehensive Users’ Defined Subroutine (UDS) was used in the FLUENT code to model the methane hydrate dissociation by depressurization. The kinetic model and equilibrium condition were contained in the UDS. The new UDS can model the heat and mass transfer during the decomposition process of methane hydrate. The behavior of the methane hydrate decomposition process in both laboratory-scale simulation and micro channels simulation was investigated in this paper. The laboratory-scale simulation results were compared with ones of the laboratory-scale system studied by Masuda et al. to verify the UDS. Evolutions of methane gas, water and hydrate in the cross micro channels were obtained. The phenomenon of water freezing was predicted by comparing the water temperature and freezing temperature. The results also showed that the dissociation process of gas hydrates as well as the water freezing phenomenon occur not only in the interface between hydrate layer and production zone, but also deep in the hydrate zone.


2018 ◽  
Author(s):  
Mingjun Yang ◽  
Yi Gao ◽  
Hang Zhou ◽  
Bingbing Chen ◽  
Yongchen Song

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 590
Author(s):  
Lihua Wan ◽  
Xiaoya Zang ◽  
Juan Fu ◽  
Xuebing Zhou ◽  
Jingsheng Lu ◽  
...  

The large amounts of natural gas in a dense solid phase stored in the confined environment of porous materials have become a new, potential method for storing and transporting natural gas. However, there is no experimental evidence to accurately determine the phase state of water during nanoscale gas hydrate dissociation. The results on the dissociation behavior of methane hydrates confined in a nanosilica gel and the contained water phase state during hydrate dissociation at temperatures below the ice point and under atmospheric pressure are presented. Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD) were used to trace the dissociation of confined methane hydrate synthesized from pore water confined inside the nanosilica gel. The characterization of the confined methane hydrate was also analyzed by PXRD. It was found that the confined methane hydrates dissociated into ultra viscous low-density liquid water (LDL) and methane gas. The results showed that the mechanism of confined methane hydrate dissociation at temperatures below the ice point depended on the phase state of water during hydrate dissociation.


2002 ◽  
Author(s):  
Liviu Tomutsa ◽  
Barry Freifeld ◽  
Timothy J. Kneafsey ◽  
Laura A. Stern

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