滨里海盆地M区块盐下构造变速成图  

Variable-velocity mapping for sub-salt structure in Block M,Pre-Caspian Basin

作　　者：杨勤林[1,2] 王彦春[1] 张静[2] 刘文卿[2] 肖明图[2] 

机构地区：[1]中国地质大学(北京)地球物理与信息技术学院,北京100083 [2]中国石油天然气股份有限公司勘探开发研究院西北分院,甘肃兰州730020

出　　处：《石油物探》2012年第4期377-382,317,共6页Geophysical Prospecting For Petroleum

基　　金：中国石油天然气股份有限公司科学研究与技术开发项目(2008E-1606)资助

摘　　要：滨里海盆地M区块在二叠系发育巨厚盐岩层,盐丘与围岩速度的巨大差异造成地震时间剖面上盐下反射同相轴上拉,形成构造假象,给钻井部署带来很大困难。在分析了含盐盆地的速度特征和变速成图难点的基础上,首先对地震叠加速度谱异常进行编辑;然后利用相干反演法沿层求取层速度,并结合测井资料优化层速度场;最后采用图形偏移法进行时深转换和构造成图。采用上述变速成图方法形成的M区块构造图消除了盐丘速度的影响,反映了盐下构造的真实形态。The Permian formation has developed giant thick salt domes in the Block M,Pre-Caspian basin.Because of the huge velocity difference between the salt domes and surrounding rocks,the sub-salt seismic events are pulled up in time sections and displays structure artifacts,which brings difficulty in well deployment.Based on analyzing the characteristics of the velocity and the difficulties in the variable-velocity mapping of saliferous basins,we firstly edited the anomalies in seismic stack velocity spectrum,then calculated the layer velocity through coherent inversion and optimized the velocity field combined with logging data.Finally,we carried out time-depth conversion and structure mapping by using map migration method.By using the above workflow,the structure map of Block M was obtained,and the impact of salt-dome velocity was removed,which displays the actual shape of sub-salt structure.

关 键 词：滨里海盆地 盐下构造 变速成图 相干反演法 图形偏移 

分 类 号：P631.4[天文地球—地质矿产勘探]