基于成像域的多次波压制

Multiple attenuation based on image space

常规多次波压制方法大都是在数据域基于滤波理论或者波动理论实现的,这些方法都不能有效地兼顾多次波压制精度和计算效率。为此,本文将波动理论与滤波理论相结合,基于成像角度域共成像点道集(ADCIGs)实现多次波压制。首先对成像域多次波映射进行了讨论,通过推导可知,成像域ADCIGs中多次波和一次波剩余时差不同,这一结论即为在成像域应用滤波方法压制多次波的理论基础;考虑到基于DSR方程的叠前深度偏移可以获得更多的角度信息,然后基于DSR方程提取ADCIGs,再引入适用于ADCIGs的正切平方估计高分辨率拉东变换分离一次波和多次波,实现多次波压制。由于本文方法将波动理论与滤波理论相结合,因此能同时兼顾多次波压制精度和计算效率,模型试算和实际资料处理验证了方法的有效性。

Conventional multiple attenuation methods are mostly completed based on filtering theory or wave theory in data space.Usually,these methods cannot effectively guarantee multiple attenuation accuracy and computational efficiency at the same time. Therefore,we do multiple suppression based on angle-domain common-image gathers(ADCIGs) combining the wave theory with the filtering theory.Firstly,image space mapping of multiples is discussed in the paper.By derivation we get the following conclusion:there are different residual moveouts between multiples and primaries in ADCIGs,so filtering method can be used to suppress multiples in image space.Considering that more angle information can be gained by prestack depth migration based on DSR equation,here we extract ADCIGs based on DSR equation,and introduce the tangent-squared approximation high resolution Radon transform which is more suitable for ADCIGs to separate primaries and multiples.Since this method combine wave theory with filtering theory, the multiple attenuation accuracy and computational efficiency can be taken into account at the same time.Model and real data processing results have verified the effectiveness of this method.