弹性波逆时偏移子波拉伸校正  

Wavelet Stretch Correction in Elastic Wave Reverse Time Migration

作　　者：杨绍伟[1] 何兵寿[1] 杨佳佳[2] 

机构地区：[1]中国海洋大学,海底科学与探测技术教育部重点实验室,山东青岛266100 [2]青岛海洋地质研究所,山东青岛266071

出　　处：《中国煤炭地质》2016年第2期61-67,77,共8页Coal Geology of China

基　　金：国家自然科学基金资助项目(41174087,41204089);国家科技重大专项项目(2011ZX05005-005);863项目(2013AA064201)

摘　　要：弹性波逆时偏移的子波拉伸效应是指偏移后纵横波在垂向(深度)上的子波延续长度和频率随地震波速度、地层倾角和反射角的变化而变化。通过研究弹性波逆时偏移中的纵、横波子波拉伸效应,提出了相应的校正方法:提取弹性波延拓过程中各成像点在成像时刻的震源波场和接收点波场的地震子波,以不改变成像结果的振幅与相位为前提,在波场延拓后,应用成像条件前对纵横波进行子波压缩处理,消除地震波速度、地层倾角和反射角等因素对纵横波延续长度和频率的影响。数值算例表明,该方法可提高逆时偏移后纵横波的垂向分辨率与振幅保真性,为后期进行AVO/AVA或其它叠前反演工作提供输入数据。The effect of wavelet stretch in elastic wave reverse time migration（RTM） refers to P-wave, S-wave vertical（depth） wavelet extended length and frequency varying along with seismic-wave velocity, strata dip and angle of reflection. The paper is mainly studied the effect of wavelet stretch in elastic wave RTM and correction method. Through the pick up of seismic wavelet in source wave field and receiving point wave field imaging point and imaging time during elastic wave spreading process. Taking the unchanged imaging result amplitude and phase as prerequisite, carried out P-wave and S-wave wavelet compressing after wave field spreading, before imaging condition applied, to eliminate impacts from seismic-wave velocity, strata dip and angle of reflection on P-wave, S-wave extended length and frequency. The numerical examples have shown that the method can improve P-wave and S-wave vertical resolution and amplitude fidelity, provide data-in for later AVO/AVA or other prestack conversions.

关 键 词：弹性波 逆时偏移 子波拉伸校正 分辨率 AVO分析 

分 类 号：P631.4[天文地球—地质矿产勘探]