基于可逆叠加变换的地滚波压制技术  

Ground roll suppression based on invertible superposition transformation

作　　者：吴玉[1] WU Yu(Sinopec Geophysical Research Institute Co.,Ltd.,Nanjing211103,China)

机构地区：[1]中国石油化工股份有限公司石油物探技术研究院,江苏南京211103

出　　处：《物探与化探》2023年第6期1573-1579,共7页Geophysical and Geochemical Exploration

基　　金：中石化科技部项目(P21050)。

摘　　要：地滚波是一种常见规则干扰,具有低频、低速、强能量、频散的特征,由于地滚波和有效波在频带、传播方向、速度等方面存在重叠,导致变换域滤波方法很难取得理想的效果。目前,工业界主流的地滚波压制技术是预测+匹配相减,由于近地表复杂的波场传播过程,直接对地滚波进行预测建模通常很困难并且精度有限。本文提出了一种基于可逆叠加变换的地滚波压制新技术,通过叠加算子对CMP域反射波进行建模,构建一个反射波估计的反问题,使用最优化方法求解此反问题,相当于把地震数据向反射波空间投影。由于地滚波和反射波处在不同的空间,通过投影能够得到干净的反射波数据。为了降低地滚波对反演结果的影响,本文进一步引入数据预条件算子减少地滚波的泄露,能够得到更好的噪声压制效果。Ground roll is a type of common regular noise and features low frequency,low velocity,strong energy,and dispersion.It over-laps with effective waves in terms of frequency bands,propagation direction,and velocity,making the transform-domain filtering methods fail to yield desired denoising results.At present,prediction plus matched subtraction is the mainstream ground roll suppression tech-nique in the industry.However,direct predictive modeling of the ground roll is often difficult and of limited accuracy due to the complex wavefield propagation process near the surface.This study proposed a new ground roll suppression technique based on invertible super-position transformation.The main approach is as follows:first,the reflected waves can be modeled using a superposition operator in the CMP domain to construct an inverse problem for reflected wave estimation.Then the inverse problem is solved using an optimization method.The whole process is equivalent to the projection of seismic data to the reflection space.Since ground roll and reflection waves reside in different spaces,clean reflected wave data can be obtained through projection.To reduce the influence of ground roll on inver-sion results,this study used a data preconditioner to reduce the leakage of ground roll,achieving effective noise suppression effects.

关 键 词：地滚波 叠加算子 可逆算子 CMP域 

分 类 号：P631.4[天文地球—地质矿产勘探]