面向井周高陡构造的VSP地震干涉成像方法研究  

Seismic interferometry for high-steep structures around wells

作　　者：燕新跃 谷丙洛 孙志广 张永杰 张鑫怡 YAN Xinyue;GU Bingluo;SUN Zhiguang;ZHANG Yongjie;ZHANG Xinyi(China University of Petroleum,Qingdao,Shandong,266580)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580

出　　处：《地质论评》2024年第5期1873-1883,共11页Geological Review

基　　金：国家自然科学基金资助项目(编号:42004093);山东省自然科学基金资助项目(编号:ZR2020QD050)的成果。

摘　　要：随着我国油气勘探的不断深入,复杂高陡构造区越来越成为当今油气勘探的重点,现有成像方法无法满足井周高陡构造的成像需求。针对井中高陡构造,地震干涉法基于源检互易定理,对不同检波点处VSP资料进行相关/褶积处理,重构虚拟震源数据,得到以某一检波点为虚拟震源,另一检波点处接收到的虚拟SWP地震记录。根据地震干涉原理,将VSP资料的不同波场成分进行分离,并对不同波场成分进行数学运算来生成干涉道集。通过地震干涉法能够使虚拟观测系统更靠近目标区域,提高对高陡界面的成像分辨率,实现面向井周高陡构造的高精度成像。笔者等先是对地震干涉原理进行理论推导,基于扰动理论对VSP干涉道集的波场成分进行分析,验证了不同波场成分在地震干涉中的作用及虚假同相轴产生原因。引入窗函数滤波器,对远离虚拟源和虚拟检波器的记录进行衰减,压制干涉过程中生成的虚假同相轴。最后利用干涉成像条件对处理后的地震资料进行成像,并用盐丘模型进行数值试算,得到其高精度成像结果。Objectives:With the continuous deepening of oil and gas exploration in China,complex high-steep structural areas have increasingly become the focus of oil and gas exploration.The existing imaging methods cannot meet the imaging requirements of high-steep structures around wells.According to the principle of seismic interferometry,different wave field components of VSP data are separated,and different wave field components are mathematically calculated to generate interference gathers.The seismic interferometry can make the virtual observation system closer to the target area,improve the imaging resolution of the high-steep interface,and achieve high-precision imaging for the high-steep structure around the well.Methods:For the high-steep structure in the well,the seismic interferometry method is based on the source—receiver reciprocity theorem.The VSP data at different detection points are processed by correlation/convolution,and the virtual source data is reconstructed to obtain a virtual SWP seismic record with one detection point as the virtual source and the other detection point.Results:The perturbation theory is used to analyze the role of different wave field components in the interference process.Through the window function filter and seismic interference imaging method,the salt dome model is imaged and compared with the reverse-time migration imaging effect,and the high-precision imaging of the salt dome model is obtained.Conclusions:Using seismic interferometry,VSP wave field can be transformed into SWP wave field,which makes the observation system closer to the underground structure and realizes high-precision imaging of underground high-steep structures.

关 键 词：高陡构造 地震干涉 上下行波分离 扰动理论 

分 类 号：P631[天文地球—地质矿产勘探]