音频大地电磁测深法探测冻土区天然气水合物有效性实验  

Effectiveness of audio magnetotelluric sounding for detecting gas hydrate in permafrost regions

作　　者：方慧[1,2] 裴发根[1,2] 何梅兴[1,2] 白大为[1,2] 胡祥云[3] 钟清[1,2] 杜炳锐[1,2] 张小博[1,2] 卢景奇[1,2] 

机构地区：[1]国土资源部地球物理电磁法探测技术重点实验室,河北廊坊065000 [2]中国地质科学院地球物理地球化学勘查研究所,河北廊坊065000 [3]中国地质大学(武汉)地球物理与空间信息学院,湖北武汉430074

出　　处：《物探与化探》2017年第6期1068-1074,共7页Geophysical and Geochemical Exploration

基　　金：国家高技术研究发展计划("863"计划)课题(2012AA061403);国家127专项项目(GZHL20110324;GZH201400305);国土资源部公益性行业科研专项项目(201111019);中国地质调查局地质调查项目(DD20160224)

摘　　要：我国青藏高原永久冻土区具备良好的天然气水合物成矿条件和找矿前景,缺少有效的勘查技术已经成为影响我国陆域水合物资源调查与评价工作的重要瓶颈。在木里地区开展了音频大地电磁测深法探测天然气水合物方法有效性实验研究,结果表明:音频大地电磁测深法在探测冻土和水合物方面是有效的。研究区冻土发育,但厚度变化较大,冻土发育状况对水合物成藏有一定控制作用。天然气水合物矿体在电性上表现出三大特征,这些特征可以作为判断水合物成藏的识别标志。水合物成藏受坳陷南缘的逆冲断裂(F_1、F_2)控制明显,断裂带不仅是气体运移通道,也是水合物成藏空间。研究结果对推动我国陆域天然气水合物勘探技术进步和水合物资源调查与评价工作有积极意义。The permafrost area of the Tibetan Plateau has good gas hydrate ore-forming condition and prospecting vista; nevertheless, the lack of effective exploration techniques has become an serious bottleneck affecting the investigation and evaluation of land gas hydrate resources. In this paper, experimental study of the effectiveness of detection of gas hydrate by the audio magnetotelluric sounding method （AMT） was carried out, and the results show that the audio magnetotelluric sounding （AMT） method is an effective method for detecting the permafrost-associated gas hydrate. Permafrost is well developed in the study area, but the thickness varies greatly, which has a certain control over gas hydrate formation. Gas hydrate orebodies show three characteristics in electrical property. These character- istics can be used as an identification markers for gas hydrate formation. The hydrate accumulation is controlled by reverse thrust frac- tures （ F1 and F2 ） on the southern margin of the depression. The fault zone is not only a gas migration channel but also a gas hydrate accumulation space. The research results have positive significance for promoting land gas hydrate exploration technology and resources investigation and evaluation in China.

关 键 词：天然气水合物 音频大地电磁测深法 祁连山木里地区 水合物电性特征 

分 类 号：P631[天文地球—地质矿产勘探]