南海南部深水多次波模拟分析与压制处理

南海南部陆缘构造复杂多变,海底崎岖不平,造成该区多道地震资料多次波十分发育且混杂复杂绕射波。为了识别深层有效反射信息、压制多次波,首先通过正演模拟分析深水条件下多次波的传播规律和特征,然后对复杂理论Pluto模型进行详细处理并试验了几种典型多次波压制方法,寻找到一套有效的多次波压制处理思路:通过表面相关多次波衰减(SRME)法降低多次波能量级别,运用τ-p域预测反褶积压制周期规律的近中道多次波,再在此基础上灵活运用高分辨率抛物线Radon变换对共反射点道集(CRP)进行中远道多次波压制。理论模型和礼乐盆地海区的实际资料处理结果表明,该方法能够较大程度上压制深水资料多次波并增强对深部有效信息的识别。

Seismic Multiple Model Analysis and Processing Skills in the Deepwater Area of Southern South China Sea

Due to the complicated structure and rugged seafloor of the continental margin of the southern South China Sea,a plenty of multiples coupled with diffractions are well existed in the multichannel seismic data.To recognize effective signal from the deep and suppress multiples,firstly, we analyzed the multiple propagation law by means of forward modelling;secondly,in particular,we processed the complicated Pluto model and tested several typical multiple elimination techniques.And finally we achieved the effective processing idea:reduce the multiple energy level by Surface Related Multiple Elimination(SRME),suppress the periodic and near offset multiple by deconvolution in τ-p domain;and further suppress the far offset multiples by the Radon transform in the common reflection point(CRP)gather.The results of the theoretical model and Liyue basin seismic data demonstrate that the multiples can be suppressed to a great extent and the effective signal from the deep can be enhanced by this method.