大地电磁测深在固市凹陷基底探测与氦气勘探中的应用  

Application of magnetotelluric sounding in basement detection and helium exploration in Gushi sag

作　　者：张瑾爱 周少伟 ZHANG Jinai;ZHOU Shaowei(Shaanxi Geological Survey Center, Xi’an 710000,China)

机构地区：[1]陕西省矿产地质调查中心,西安710000

出　　处：《物探化探计算技术》2021年第4期486-493,共8页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：中国地质调查局项目(12120113040500)。

摘　　要：为了研究固市凹陷深部基底结构特征、为氦等天然气选区评价提供依据,在固市凹陷布置了D1和D2两条大地电磁测深剖面,开展大地电磁测深及综合解释评价工作。本次研究首先对固市凹陷的大地电磁测深剖面的电性特征进行定性分析,再结合二维地震剖面进行约束对其进行定量解释,划分出固市凹陷的主要地层及埋深,确定了新生界张家坡组为氦等天然气资源储集有利层位的深度和厚度。根据本次研究结果显示,大地电磁测深反演结果与地震勘探解释结果相吻合,有效反映了固市凹陷深部地层构造的真实形态,为进一步研究固市凹陷基底结构特征和氦气勘探提供借鉴。In order to study characteristics of the deep base structure of the Gushi sag and provide basis for the evaluation of natural gas selection areas such as helium,two magnetotelluric sounding profiles were arranged in the Gushi sag to carry out magnetotelluric sounding and comprehensive interpretation and evaluation.A qualitative analysis of the electrical characteristics of the magnetotelluric sounding profile in the Gushi sag was first conducted in this study,and then combined with the two-dimensional seismic profile to perform a quantitative interpretation of it.The main strata and buried depth of the Gushi sag were divided.The cenozoic Zhangjiapo group is the depth and thickness of favorable strata for natural gas resources such as helium.According to this study,the results of inversion of magnetotelluric sounding are consistent with the results of seismic exploration interpretation,which effectively reflects the true morphology of deep stratigraphic structures in the Gushi sag,and provides an effective method for further studying the base structure characteristics of the Gushi sag and helium exploration.

关 键 词：大地电磁 固市凹陷 地震勘探 深部基底 电性特征 

分 类 号：P631.2[天文地球—地质矿产勘探]