CSAMT在祁连山永久冻土区天然气水合物调查中的应用  

Application of CSAMT to Qilian Mountain Permafrost Region Gas Hydrate Investigation

作　　者：姚大为[1,2] 王书民[1] 雷达[1] 朱威[1] 王刚[1] 

机构地区：[1]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 [2]中国地质大学地球物理与信息技术学院,北京100083

出　　处：《工程地球物理学报》2013年第2期132-137,共6页Chinese Journal of Engineering Geophysics

基　　金：中国地质科学院地球物理地球化学勘查研究所基本科研业务专项资金项目(编号:AS2009J03)资助

摘　　要：根据祁连山永久冻土区区域地质背景、成矿条件和岩石物性特征,开展了CSAMT方法的探测研究。通过对CSAMT原始数据的分析解释,发现测区浅部0～100m深度段,呈现一似层状的高电阻率异常;在中深部存在纵向条带状低电阻率异常且电阻率呈现横向不连续变化。结合地质、钻孔资料得出浅部0～100m深度段的高电阻率异常为冻土层的反映,中深部呈现横向不连续的电阻率变化或纵向条带状低阻异常为断裂构造引起。因此认为CSAMT能够很好地分辨出天然气水合物形成、运移所需要的冻土盖层和断裂构造。According to the geological background,metallogenic conditions and petrophysical characteristics in Qilian Mountain permafrost area,the study of detecting the gas hydrate by controlled source audio-frequency magnetotellurics（CSAMT） was carried out.Based on the analysis and interpretation of the CSAMT original data,it＇s found that the shallow depth section in 0~100m of the measurement area presented a lay-like high resistivity anomaly and existed vertical banded low resistivity anomaly and resistivity present lateral discontinuous changes in the deep part.Combined with geological and drilling data,it was concluded that the high resistivity anomaly of the shallow depth section in 0 ~ 100m was the reflection of permafrost,and the transversal discontinuous resistivity changes or longitudinally banded low resistance anomaly was caused by fault structure.It was held that the CSAMT could distinguish permafrost and fracture structure which was needed for the formation and migration of natural gas hydrate.

关 键 词：天然气水合物 CSAMT 电阻率 祁连山永久冻土区 

分 类 号：P631.3[天文地球—地质矿产勘探]