与速度无关的叠前时间偏移成像方法  

The Pre-stack Time Migration Image Method Independent of Velocity

作　　者：王大为 李列 李林 欧阳敏 杨文博 邓聪 吴涛 Wang Dawei;Li Lie;Li Lin;Ouyang Min;Yang Wenbo;Deng Cong;Wu Tao(Zhanjiang Branch of CNOOC Ltd.,Zhanjiang Guangdong 524057,China)

机构地区：[1]中海石油有限公司湛江分公司,广东湛江524057

出　　处：《工程地球物理学报》2018年第5期586-591,共6页Chinese Journal of Engineering Geophysics

摘　　要：常规的速度分析方法及时差动校正以双曲线同相轴为基础,只适用于偏移距小于或者等于反射界面深度的条件下。近年来南海西部海域部分地震资料的最大偏移距达到8 000m,覆盖次数达到160次,常规的双曲线同相轴的假设不能精确描述长偏移距地震反射同相轴的时距关系。为了提高长偏移距地震数据动校正公式的精度,本文以长排列的时移双曲线为基础,使用与速度无关的非双曲线走时方法实现对常规动校正公式大偏移距误差的修正,进而进行与速度无关的DMO(Dip Moveout Correction),最终实现了长偏移距地震资料与速度无关的叠前时间偏移,并在模型及实际数据测试中均取得了较好的效果。The conventional velocity analysis and normal moveout are based on hyperbolic event, only appling to the term that offset is less than or equal to the depth of reflector. In recent years, the maximum offset of seismic data has reached 8000 meters in the South China Sea, and the folds reached 160 times, so the conventional hyperbolic event is not suitable for the time and distance relationship of long array seismic data event; To improve the accuracy of long array seismic data NMO（Normal Moveout Correction）, based on the time shift hyperbola of long array this paper revises the error of long array seismic data using conventional NMO by means of non-hyperbolic travel time method independent of velocity , then carries on the DMO（Dip Moveout Correction）independent of velocity. At last this paper achieves the PSTM（Pre-stack time migration） of long array seismic data independent of velocity, and gets good results in the test of the model and real data.

关 键 词：地震数据 长排列 非双曲线 同相轴 动校正 速度无关 成像 

分 类 号：P631.4[天文地球—地质矿产勘探]