Characteristics of methane seepage and gas hydrate reservoir in the northeastern slope of South China Sea

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  • 1.China University of Geosciences(Wuhan),Wuhan 430074,China;
    2.Key Laboratory of Marine Mineral Resources,MLR,Guangzhou Marine Geological Survey,Guangzhou 510075,China

Received date: 2016-06-28

  Revised date: 2017-02-18

  Online published: 2017-05-10

Abstract

In this paper,the characteristics of methane seepage and its impact on methane hydrate accumulation in addition to the formation model of methane hydrate in the northeastern slope of South China Sea are analyzed by using geological,geophysical and geochemical data during recent investigation as well as drilling results of GMGS2 in 2013.A seepage system with high methane flux in our study area is inferred from evidences of seeps-related geological features,geochemical anomalies.In addition,abundant massive,vein,and nodular gas hydratewere found and its formation is probably associated with high methane flux seepage.Free methane migrates along faults or factures upward to shallower strata,resulting in gas seepage occurring in variable depths within gas hydrate stability zone,which presented as gas chimneys.Methane hydrate reservoirs are inferred to form on the top or flanks of gas chimneys.The faults associated with methane hydrate accumulation consist of active regional normal faults,localized faults,and shallow active faults related toseafloor instability.The accumulation of localized visible methane hydrate is mainly controlled by the gas chimneys.

Cite this article

Liang Jin-qiang,Fu Shao-ying,Chen Fang,Su Pi-bo,Shang Jiu-jing,Lu Hong-feng,Fang Yun-xin . Characteristics of methane seepage and gas hydrate reservoir in the northeastern slope of South China Sea[J]. Natural Gas Geoscience, 2017 , 28(5) : 761 -770 . DOI: 10.11764/j.issn.1672-1926.2017.02.006

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