A study of the effectiveness of the high precision seismic method in detecting land natural gas hydrate
GAO Jing-Hua1, 2, LIU Jian-Xun1, 2, ZHANG Bao-Wei1, 2, WANG Xiao-Jiang1, 2, XU Ming-Cai1, 2
1.National Modern Geological Exploration Technology Research Center,Langfang 065000,China; 2.Institute of Geophysical and Geochemical Exploration,CAGS,Langfang 065000,China
Abstract:In order to cooperate with the exploration of natural gas hydrate resources,the authors conducted the validity of the experimental study of high precision seismic reflection method in Muli area for the detection of natural gas hydrate in 2010.192 receive channels,2 m group spacing,8 m shot spacing,and 24 folds were used in reflection seismic survey.60 Hz geophone string (with 6 geophones) each received channel received seismic wave in the form of point array.Excitation sources were explosives, shot depth was 3~4 m,and shot charge was 1.2~2.4 kg.The seismic sections obtained by the method possessed high S/N ratio and resolution as well as obvious structural form characteristics.On the basis of a comprehensive analysis and interpretation of reflection seismic,well logging and geological data,the enrichment zones of natural gas hydrate were explained and validated borehole location was determined. The detection results were verified by DK9 borehole drilling in 2013.The gas hydrate reservoirs with large thickness were found 450m southwest of DK3 borehole.Experimental results show that it is difficult to detect natural gas hydrate directly by seismic method in the lower gas hydrate content's area,but through a comprehensive analysis of geophysical,geochemical and geological data in combination with drilling data,the enrichment zones of natural gas hydrate can be detected by seismic exploration.
高景华, 刘建勋, 张保卫, 王小江, 徐明才. 高精度地震探测陆域天然气水合物的有效性研究[J]. 物探与化探, 2017, 41(6): 1005-1011.
GAO Jing-Hua, LIU Jian-Xun, ZHANG Bao-Wei, WANG Xiao-Jiang, XU Ming-Cai. A study of the effectiveness of the high precision seismic method in detecting land natural gas hydrate. Geophysical and Geochemical Exploration, 2017, 41(6): 1005-1011.
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