民丰凹陷大地电磁探测研究  

A magnetotelluric survey in Minfeng Sag

作　　者：程正璞 胡祥云[1] 李烨[1] 陈宇峰[1] 徐珊[1] 

机构地区：[1]中国地质大学(武汉)地球物理与空间信息学院,湖北武汉430074 [2]中国地质调查局水文地质环境地质调查中心,河北保定071051

出　　处：《石油地球物理勘探》2016年第2期391-403,210,共13页Oil Geophysical Prospecting

基　　金：国家深部探测专项(SinoProbe-02);国家自然科学基金(41274077);国家"973"项目(2013CB733203)联合资助

摘　　要：利用＂深部探测技术与试验研究（SinoProbe）＂项目在塔里木盆地东南边缘民丰凹陷37°N、84°E建立的大地电磁标准点实测数据,对民丰凹陷深部电性结构进行了研究。采用Robust方法对实测数据进行处理,并进行极化模式识别、静校正、二维偏离度及磁感应矢量分析,最终采用非线性共轭梯度法（NLCG）对该测区的两条剖面进行了带地形的二维反演。通过对反演结果的分析可知,民丰凹陷地下结构具有较好的电性分层,结合塔东南区域地质概况,推测其莫霍面深度约为41-43km,并且推测基底发育两条断层（F1、F2）。另外通过计算民丰凹陷地壳构造特征参数得出该区地壳结构适宜油气成藏,烃源岩发育,但成熟度不高,属于一般油气区。We analyze deep conductivity structures based on MT data acquired at standard points(36°N84°E)in Minfeng Sag,southeast Tarim Basin,which is a part of SinoProbe project.First we process MT data with the Robust method,and then carry out polarization pattern recognition,static corrections,and 2D-approximator and induction arrow vector analysis.Finally,we conduct 2Dinversion of two profiles with nonlinear conjugate gradient(NLCG).The inversion results show that the subsurface in Minfeng Sag possesses good electrical layered structures.According to the regional geological conditions,we conclude that the Moho depth is about 41 to 43km and 2faults exist above the basement. Crustal structures of Minfeng Sag might be suitable for hydrocarbon accumulation based on crustal tectonic characteristic parameter calculation.Hydrocarbon source rock might be developed,but its maturity could not be high.

关 键 词：民丰凹陷 大地电磁 电性分层 莫霍面 油气成藏 

分 类 号：P631.3[天文地球—地质矿产勘探]