初至拾取中基于超级虚折射干涉的信号加强  

Signal enhancement based on super-virtual refraction interferometry in first arrival pickup

作　　者：梁上林 胡天跃[1] 崔栋 胡英[2] 张研[2] LIANG Shanglin;HU Tianyue;CUI Dong;HU Ying;ZHANG Yan(School of Earth and Space Sciences,Peking University,Beijing 100871,China;Research Institute of Petroleum Exploration and Development,Petrochina,Beijing 100083,China)

机构地区：[1]北京大学地球与空间科学学院,北京100871 [2]中国石油天然气股份有限公司勘探开发研究院,北京100083

出　　处：《石油物探》2019年第4期509-516,共8页Geophysical Prospecting For Petroleum

基　　金：国家科技重大专项(2016ZX05004003);国家自然科学基金(41674122);国家重点基础研究发展(973)计划(2013CB228602)共同资助~~

摘　　要：中国西部山区地形起伏大,地震资料能量弱、信噪比低,难以准确拾取初至.基于稳相叠加原理,超级虚折射干涉可有效加强弱初至信号.首先,针对超级虚折射干涉叠加次数不均导致振幅不一致的问题,将相关型超级虚折射干涉和褶积型超级虚折射干涉结合起来形成混合型超级虚折射干涉,保证叠加次数的一致性;其次,为进一步增加折射波初至的叠加次数,提出了炮点域和检波点域联合叠加方法;然后,针对互相关或褶积都会产生子波旁瓣的问题,引入反褶积处理,对由混合超级虚折射干涉得到的虚折射波场进行反褶积处理,压制旁瓣,弥补远偏移距数据的高频损失;最后,针对实际资料的处理,设计了具体的初至拾取中基于超级虚折射干涉的信号加强的技术流程,有利于实现方法的工业化应用.模型试验和实际资料应用结果表明,该方法可有效增加叠加次数,加强远道低能量初至,提高资料的信噪比,为静校正等后续处理提供高质量基础资料.It is difficult to accurately pick the first arrival of a seismic wave.In the mountainous areas of western China,this might be due to the great topographic relief,the weak energy,and the low signal-to-noise ratio (SNR) of the seismic data.Based on the principle of the stationary phase stack,the super-virtual refraction interferometry can effectively enhance weak signals and simplify the pickup of the first arrival.In this study,with the aim of addressing the problem of inconsistent amplitude caused by the uneven stack of the super-virtual refraction interferometry,the cross-correlation and the convolution-type of interferometry are combined into a blend-type interferometry to ensure the consistency of the number of stacks.Subsequently,in order to further increase the stack number of the first arrival of the virtual refracted wave,it is proposed to stack jointly in both source and receiver domains.Moreover,to address the problem of wavelet sidelobe,which is generated by cross-correlation or convolution,a deconvolution is introduced,so that the influence of the wavelet sidelobe can be reduced and the energy loss for the far offset data can be compensated.Finally,the technical process of signal enhancement based on the super-virtual refraction interferometry in first arrival identification is utilized to solve field data.This technical process is suitable for industrial application.Tests on both model and field data showed that the method can effectively enhance the low-energy first arrival of far-field data,so that the first arrival can be identified with high precision,the SNR of the seismic data can be improved,and high-quality input data can be provided for subsequent processing,such as static correction.

关 键 词：超级虚折射干涉 折射波 反褶积 低信噪比 初至加强 炮检域 

分 类 号：P631[天文地球—地质矿产勘探]