石油地球物理勘探2025，Vol.60Issue(2)：411-419,9.DOI:10.13810/j.cnki.issn.1000-7210.20240114
震源子波与最小二乘偏移分辨率的关系及优化调整方法
Adjustment of source wavelet based on the relationship with the resolution of least-squares migration
摘要
Abstract
Source wavelet is an important parameter to determine the resolution of the least-squares migration(LSM).However,the actual seismic wavelet is a non-stationary signal that is difficult to be accurately esti-mated,and the errors in the source wavelet inevitably affect the effect of LSM.To ensure the application effect of LSM,firstly,this paper compares and analyzes the imaging resolution characteristics between conventional migration and LSM theoretically,and then reveals the influence of source wavelet with different dominant fre-quency and band width errors on the resolution of LSM through theoretical model tests.Specifically,wavelets with higher/lower dominant frequencies result in imaging results with lower/higher frequencies,wavelets with narrower/wider bandwidths lead to spectrum distortion or reduced broadband extension in imaging results.Only when the selected wavelet matches the wavelet in the seismic data can LSM achieve the broadest fre-quency bandwidth and the highest-resolution.Finally,an optimization and adjustment method for source wave-lets is proposed:①When the LSM results exhibit significant high/low-frequency effects,the dominant fre-quency of the source wavelet can be increased/decreased for adjustment.②When the energy in a specific fre-quency band of the LSM results is excessively high,the spectrum of the source wavelet in that frequency band can be boosted for correction.③When the broadband extension effect of the LSM results is weak,narrowing the bandwidth of the source wavelet can improve the broadband extension.关键词
最小二乘偏移/震源子波/成像分辨率/子波优化/反褶积Key words
least-squares migration/source wavelet/the resolution of imaging/wavelet optimization/decon-volution分类
地质学引用本文复制引用
岳玉波,汤光顺,徐蔚亚,文建军,李伟,李凌云..震源子波与最小二乘偏移分辨率的关系及优化调整方法[J].石油地球物理勘探,2025,60(2):411-419,9.基金项目
本项研究受国家自然科学基金项目"快速成像域真振幅最小二乘偏移"(42074173)、"基于射线理论点扩散函数的深度域波阻抗反演"(42374161)、四川省自然科学基金项目"面向角度相关反射系数的高保真地震反演成像方法研究"(2024NSFSC0082)、中国石化弹性波理论与探测技术重点实验室开放基金项目"纵横波联合网格层析速度反演技术"(33550000-22-ZC0613-0303)联合资助. （42074173）
