镇巴地区MT资料采集技术与资料处理方法探讨  

Discussion on MT data acquisition technique and processing method in Zhenba area

作　　者：杨振升[1,2] 顾锦才 

机构地区：[1]中科院地质与地球物理研究所,北京100029 [2]华东石油局第六物探大队,江苏南京210009

出　　处：《石油地球物理勘探》2009年第2期240-247,共8页Oil Geophysical Prospecting

摘　　要：位于大巴山腹地的镇巴地区受高陡山地及复杂地下地质构造的影响,油气勘探程度低、勘探效果差。本文通过电极距、布极方式、电极组合、坡度对MT资料的影响等参数试验资料的分析研究,探讨了适合该区地形特点的MT采集方法及生产因素。结合二维正演模型的研究,对山区复杂地表类型的MT曲线的变化特征、表层不均匀体影响、地形起伏影响及地质构造干扰引起的"超相位"现象的原因进行了分析探讨;强调MT数据预处理及物性分析工作的重要性,提出了综合利用有限的地质、地震、钻井等资料,通过约束建模,进行高陡复杂山地二维层状介质反演成像,从而为区域选区评价提供可靠的基础资料。The Zhenba area,situated in hinterland of Dabashan Mountain and affected by high and steep mountains and complex underground geologic structures,is characterized by lower oil/gas exploration degree and poorer exploration effect.Through analyzing and studying the experimental data of influence of such parameters as electrode spacing,configuration,array and slope on MT data,the paper discussed MT acquisition method and production factors suitable for the topographic feature in the area.In combination with study of 2D forward simulation,the paper also carried out the analysis and discussion on the reasons of 'over-phase' resulted from the variation characters of MT curves in complex surface types of mountains,influence of subsurface non-uniform bodies,influence of topographic inequality and interference of geologic structure;highlighted the importance of MT data preprocessing and analysis of physical property;presented integrative use of limit geologic,seismic and drilling data in high and steep complex mountains and constrain model-building to carry out the inversion imaging of 2D layered medium,thus providing reliable basic data for regional area-selected evaluation.

关 键 词：大地电磁 视电阻率 畸变 正演研究 反演成像 

分 类 号：P631.325[天文地球—地质矿产勘探] P618.13[天文地球—地质学]