Phase Equilibria of Natural Gas Hydrates in Bulk Brine and Marine Sediments from the South China Sea

2021 ◽  
Author(s):  
Lantao Geng ◽  
Jin Cai ◽  
Cheng Lu ◽  
Xuwen Qin ◽  
Rongrong Qi ◽  
...  
Keyword(s):  
Natural Gas ◽  
South China Sea ◽  
Phase Equilibria ◽  
Marine Sediments ◽  
South China ◽  
Gas Hydrates ◽  
The South China Sea ◽  
The South ◽  
China Sea ◽  
Natural Gas Hydrates

Estimation of China's production efficiency of natural gas hydrates in the South China Sea

2018 ◽  
Vol 203 ◽  
pp. 1-12 ◽  
Author(s):  
Zhaoyang Kong ◽  
Qingzhe Jiang ◽  
Xiucheng Dong ◽  
Jiang Wang ◽  
Xin Wan
Keyword(s):  
Natural Gas ◽  
South China Sea ◽  
South China ◽  
Gas Hydrates ◽  
Production Efficiency ◽  
The South China Sea ◽  
The South ◽  
China Sea ◽  
Natural Gas Hydrates

scholarly journals Reservoir stability in the process of natural gas hydrate production by depressurization in the shenhu area of the south China sea

2018 ◽  
Vol 5 (6) ◽  
pp. 631-643 ◽  
Author(s):  
Yizhao Wan ◽  
Nengyou Wu ◽  
Gaowei Hu ◽  
Xin Xin ◽  
Guangrong Jin ◽  
...  
Keyword(s):  
Natural Gas ◽  
South China Sea ◽  
South China ◽  
Gas Hydrate ◽  
The South China Sea ◽  
Natural Gas Hydrate ◽  
The South ◽  
Shenhu Area ◽  
China Sea

scholarly journals Strength Behaviors of Remolded Hydrate-Bearing Marine Sediments in Different Drilling Depths of the South China Sea

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 253 ◽  
Author(s):  
Yanghui Li ◽  
Tingting Luo ◽  
Xiang Sun ◽  
Weiguo Liu ◽  
Qingping Li ◽  
...  
Keyword(s):  
South China Sea ◽  
Marine Sediments ◽  
South China ◽  
The South China Sea ◽  
Triaxial Tests ◽  
Failure Strength ◽  
The South ◽  
Drilling Depth ◽  
China Sea ◽  
Hydrate Reservoirs

The mechanical behaviors of hydrate-bearing marine sediments (HBMS) drilled from the seafloor need to be understood in order to safely exploit natural gas from marine hydrate reservoirs. In this study, hydrates were prepared using ice powder and CH4 gas, and HBMS from the Shenhu area in the South China Sea were remolded using a mixed sample preparation method. A series of triaxial tests were conducted on the remolded HBMS to investigate the effects of soil particle gradation and the existence of hydrate on the mechanical properties of hydrate reservoirs. The results show that the stiffness and failure strength of HBMS decrease along with the decrease of mean particle size and soil aggregate morphology change at different drilling depths, and the reduction of failure strength is more than 20% when the drilling depth drops by 30 m. A better particle gradation of marine sediments may boost the stiffness and failure strength of HBMS. In addition, the existence of hydrate plays an important role in the strength behaviors of HBMS. The reduction of failure strength of HBMS with 30% initial hydrate saturation is more than 35% after complete hydrate dissociation.

scholarly journals Petrographical and Geochemical Signatures Linked to Fe/Mn Reduction in Subsurface Marine Sediments from the Hydrate-Bearing Area, Dongsha, the South China Sea

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 624 ◽  
Author(s):  
Xi Xiao ◽  
Qian-Zhi Zhou ◽  
Shao-Ying Fu ◽  
Qian-Yong Liang ◽  
Xiang-Po Xu ◽  
...  
Keyword(s):  
Organic Matter ◽  
South China Sea ◽  
Marine Sediments ◽  
South China ◽  
Inorganic Carbon ◽  
Solid Phase ◽  
The South China Sea ◽  
Anaerobic Oxidation Of Methane ◽  
The South ◽  
China Sea

Fe and Mn oxides and (oxy)-hydroxides are the most abundant solid-phase electron acceptors in marine sediments, and dissimilatory Fe/Mn reduction usually links with the anaerobic oxidation of methane (AOM) and organic matter oxidation (OMO) in sediments. In this study, we report the results from subsurface marine sediments in the Dongsha hydrate-bearing area in the South China Sea. The petrological and geochemical signatures show that the Fe/Mn reduction mediated by AOM and OMO might occur in sediments above the sulfate-methane transition zone. X-ray diffraction and scanning electron microscopy analyses of sediments indicate that Fe(III)/Mn(IV)-oxides and authigenic carbonate minerals coexisted in the Fe/Mn reduction zone. The lower δ13C values of dissolved inorganic carbon, coupled with an evident increase in total inorganic carbon contents and a decrease in Ca2+ and Mg2+ concentrations indicate the onset of AOM in this zone, and the greater variation of PO43− and NH4+ concentrations in pore water suggests the higher OMO rates in subsurface sediments. Geochemical and mineralogical analyses suggest that the previously buried Fe(III)/Mn(IV) oxides might be activated and lead to the onset of Fe/Mn reduction induced by AOM and OMO. These findings may extend our understanding of the biogeochemical processes involved in Fe/Mn reduction in continental shelves with abundant methane, organic matter, and terrigenous metal oxides.

scholarly journals Seismic Expression of Polygonal Faults and Its Impact on Fluid Flow Migration for Gas Hydrates Formation in Deep Water of the South China Sea

2011 ◽  
Vol 2011 ◽  
pp. 1-7
Author(s):  
Duanxin Chen ◽  
Shiguo Wu ◽  
Xiujuan Wang ◽  
Fuliang Lv
Keyword(s):  
Fluid Flow ◽  
South China Sea ◽  
South China ◽  
Gas Hydrates ◽  
Three Dimensional ◽  
The South China Sea ◽  
Normal Faults ◽  
The South ◽  
China Sea ◽  
3D Seismic Data

Polygonal faults were identified from three-dimensional (3D) seismic data in the middle-late Miocene marine sequences of the South China Sea. Polygonal faults in the study area are normal faults with fault lengths ranging from 100 to 1500 m, fault spaces ranging from 40 to 800 m, and throws ranging from 10 to 40 m. Gas hydrate was inferred from the seismic polarity, the reflection strength, and the temperature-pressure equilibrium computation results. Gas hydrates located in the sediments above the polygonal faults layer. Polygonal faults can act as pathways for the migration of fluid flow, which can supply hydrocarbons for the formation of gas hydrates.

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