基于地震干涉法的叠后层间多次波衰减方法

Poststack interbed multiple suppression based on seismic interferometry

层间多次波衰减一直是地震数据处理的一个难题。传统的SRME法可较好地预测自由表面多次波,但无法直接预测层间多次波。基于地震干涉法的叠前层间多次波衰减法可预测与强反射层相关的层间多次波,前提是具有规则化的叠前记录且其信噪比较高。本文提出基于地震干涉法的叠后层间多次波衰减法,通过三个已知波场在叠加剖面上预测出层间多次波,然后通过自适应能量匹配实现层间多次波衰减。相对于叠前层间多次波压制法,叠后层间多次波衰减具有约束条件少、无需数据规则化及对资料信噪比要求相对较低等优势,同时克服了在炮集中的中、远炮检距范围内难以拾取有效波的缺陷。模型测试和M凹陷火成岩发育区实际资料处理结果均验证了本方法的有效性。

Interbed multiple attenuation is always a challenge in seismic data processing.The conventional SRME can effectively predict surface-related multiples,but it cannot directly predict interbed multiples.Interface related interbed multiples can be predicted in prestack gathers based on seismic interferometry,which requires high single-noise ratio and regularized shot gathers.Based on the theory of seismic interferometry,we propose in this paper a method for interface related interbed multiple prediction and attenuation in poststack data.interbed multiples can be predicted on stack sections by three known wavefields,and then they can be eliminated from the stack sections by self-adapted deduction.Comparing with interbed multiple attenuation on prestack data,our approach requires fewer constraint conditions.Neither data regularization nor high single-to-noise ratio is needed.At the same time,it avoids the disadvantages of picking event at long offset.Model test and real data processing show the feasibility of the proposed method.