龙门山北段逆掩推覆构造三维地球物理模型构建  

Construction of 3D geophysical model for overthrust nappe structure in the northern section of Longmen Mountain

作　　者：王勤耕 胡善政 黄有晖[2] 杜均国 何伟 周鸣 WANG Qingeng;HU Shanzheng;HUANG Youhui;DU Junguo;HE Wei;ZHOU Ming(Southwest Geophysical Branch,BGP Inc.,CNPC,Chengdu,Sichuan 610213,China;Tarim Oilfield Company,CNPC,Korla,Xinjiang 841000,China)

机构地区：[1]东方地球物理公司西南物探分公司,四川成都610213 [2]中国石油塔里木油田分公司勘探事业部,新疆库尔勒841000

出　　处：《石油地球物理勘探》2023年第6期1359-1364,共6页Oil Geophysical Prospecting

基　　金：中国石油天然气集团有限公司科学研究与技术开发项目“物探核心装备与软件研制项目”(2021DJ3604)资助。

摘　　要：四川盆地龙门山北段发育典型的逆掩推覆构造,油气勘探潜力大。为了获得高品质的原始地震资料,需要根据三维模型正演成果优化地震采集观测系统,其中三维地球物理模型的构建是关键。为此,综合已有二维和三维地震资料解释成果、近地表调查资料等,依据不同分区的地质、地震反射特征,采用不同的方法构建地质模型;利用微测井调查结果、VSP资料等对模型进行速度赋值;利用三维弹性波动方程数值模拟验证所构建三维地球物理模型的准确性。利用该方法所建的三维地球物理模型比较直观、准确地反映了近地表结构及地下速度场变化,模拟单炮记录与野外采集单炮吻合度高,为观测系统参数论证提供了模型基础。The northern section of Longmen Mountain in the Sichuan Basin is a typical overthrust nappe structure with significant potential for oil and gas exploration.In order to obtain high-quality raw seismic data,it is necessary to optimize the seismic acquisition and observation system based on the results of forward modeling of the 3D model,which depends on the construction of a 3D geophysical model.To this end,based on the interpretation results of 2D and 3D seismic data,as well as near-surface survey data,different methods are used to construct geological models according to different geological and seismic reflection characteristics in different regions.Micrologging survey results and VSP data are used to assign velocity values to the model;the accuracy of the constructed 3D geophysical model is verified by using elastic wave equation simulation.The 3D geophysical model built using this method intuitively and accurately reflects the changes in nearsurface structure and underground velocity field.The simulated single-shot records are highly consistent with the actual single-shot records,providing a model basis for the argument of geometry system parameters.

关 键 词：龙门山北段 逆掩推覆构造 三维地球物理模型 正演模拟 

分 类 号：P631[天文地球—地质矿产勘探]