南方碳酸盐岩地区页岩气钻探井位选址中的综合物探方法应用

Application of comprehensive geophysical prospecting method in well siting for shale gas exploration in carbonate areas in east China

南方碳酸盐岩地区页岩气钻探工程面临的碳酸盐岩岩溶问题突出,因此,钻前开展近地表地球物理勘查,合理选择井位是十分必要的。以广西柳州市融安县桂融页1井井位选址为例,综合选择高密度电阻率法、音频大地电磁法及氡气测量3种方法,开展钻前井位选址研究工作,取得良好效果。桂融页1井在近地表没有钻遇断层破碎带,与综合物探解释成果基本吻合,表明综合物探方法在南方碳酸盐岩地区页岩气勘探井位选址勘查方面是有效的。本次成果为今后类似地区钻前井位选址提供了借鉴和参考。

The drilling engineering for shale gas in carbonate areas in China is facing prominent carbonate karst.It is necessary to carry out near-surface geophysical prospecting before drilling and reasonably select the well locations in order to ensure the safety of the well site and reduce the drilling engineering risks.Taking the siting of Well Guirongye-1 in Rong'an County,Liuzhou City,Guangxi Province as an example,this study conducted the application research of well siting before drilling comprehensively using three geophysical prospecting methods,namely the high-density resistivity method,the audio-frequency magnetotellurics method,and radon survey,achieving satisfactory results.Well Guirongye-1 did not encounter a fault fracture zone near the surface,which is basically consistent with the interpretation results of comprehensive geophysical prospecting.This result indicates that the comprehensive geophysical prospecting method is feasible and effective in the siting of shale gas exploration wells in the carbonate areas in south China.This study will provide a certain reference for the well siting before drilling in similar areas in the future.