地震低频信号对关键处理环节的影响分析  

Low frequency signal influences on key seismic data processing procedures

作　　者：张军华[1] 张在金 张彬彬 梁鸿贤[2] 傅金荣[2] 郭见乐[2] 

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 [2]中国石化胜利物探研究院,山东东营257022

出　　处：《石油地球物理勘探》2016年第1期54-62,19,共9页Oil Geophysical Prospecting

基　　金：胜利油田科技项目(YKW1301)资助

摘　　要：首先研究与低频关系最直接的面波压制问题,然后分别讨论了低频信号对反褶积、速度分析、动校正、叠加、叠前偏移等关键处理环节的影响。理论模型测试与实际资料处理表明:1面波压制会损失部分低频有效信号,区域滤波法比带通滤波和F-K滤波的效果要好;2低频缺失较多时反褶积会出现虚假同相轴,使一次波失真;3低频缺失会影响速度谱的能量团聚焦性,甚至会出现假的能量团,继而影响速度场的精度;4缺失低频信息会导致动校拉伸增大,缺失10Hz以下的低频信息会使动校拉伸增大达20%;5叠加后信噪比提高,但低频缺失带来的虚假同相轴比叠前道集明显;6从模型研究的结果看,低频缺失对偏移的影响比人们预期的要小。We firstly discuss in this paper surface wave suppression which is the most relative with the low-frequency data.Then we analyze respectively influences of low frequency on deconvolution,velocity analysis,NMO,stacking and prestack migration.Finally we carry out model and real data processing tests,and obtain the following observations:1Surface wave suppression may lose part of low frequency signal.Area filtering is a better method compared with band pass filtering and FK filtering;2Lack of low frequency signals will lead to false events in deconvolution and primary reflections will be inaccurate;3Lack of low frequency will affect the accumulation of energy group on velocity spectrum or cause false energy group,which dicreases the velocity field precision;4The lack of low frequency signal lead the increase of NMO stretching.The lack of low frequency 10 Hz and below will increase NMO stretching up to 20%;5The signal-to-noise ratio will increase after stacking,but the false event caused by low frequency losing is obvious than on prestack gathers;6In view of model data test,lack of low frequency causes smaller influences on migration than that people expect.

关 键 词：低频信号 面波压制 预测反褶积 速度分析 动校拉伸 叠加 叠前时间偏移 

分 类 号：P631[天文地球—地质矿产勘探]