石油物探2017，Vol.56Issue(4)：516-522,550,8.DOI:10.3969/j.issn.1000-1441.2017.04.007
利用独立伽马场的反射波时间比例转换波叠前时间偏移
Prestack time migration for a converted wave based on the independent gamma field
摘要
Abstract
Prestack time migration based on a convented wave time scale isn't suitable for P-wave and S-wave velocity analysis and can't ensure the imaging accuracy.Prestack time migration for converted wave can be realized according to the converted wave time scale or the reflection time scale.Both methods were compared and analyzed.The method using reflection time scale directly quotes the P-wave velocity obtained from reflection data,and the double square root time formula can be simplified to a separate problem for calculating the S-wave velocity,so as to effectively reduce the uncertainty.We introduce the independent gamma to the course of prestack time migration for a converted wave based on the reflection time scale;the P-wave and S-wave average velocity ratio can be acquired by time matching,accordingly.It can eliminate the effects of the offset,stratigraphic dip and other factors.On this basis,we calculated the S-wave velocity iteratively and updated the P-wave velocity continuously,and the P-wave velocity,S-wave velocity,and P-and S-wave average velocity ratio can be obtained with clear physical meaning.The practical application shows that the method has high computational efficiency and good imaging effect.关键词
转换波/叠前时间偏移/时间比例/独立伽马Key words
converted wave/prestack time migration/time scale/independent gamma分类
天文与地球科学引用本文复制引用
陈华..利用独立伽马场的反射波时间比例转换波叠前时间偏移[J].石油物探,2017,56(4):516-522,550,8.基金项目
国家科技重大专项(2016ZX05027-002)资助.This research is financially supported by the National Science and Technology Major Project of China (Grant No.2016ZX05027-002). （2016ZX05027-002）
