振幅均衡的超虚折射波场重构  

Reconstruction of amplitude-balance super-virtual refraction wavefield

作　　者：吴卫华 刘怀山[1] 雷朝阳 吴树梁 WU Weihua;LIU Huaishan;LEI Chaoyang;WU Shuliang(Key Lab of Submarine Geosciences and Prospecting Techniques, Ministry of Education, Ocean University of China,Qingdao, Shandong 266100, China;Sinopec Geophysical Research Institute, Nanjing 211103, China)

机构地区：[1]中国海洋大学海底科学与探测技术教育部重点实验室,山东青岛266100 [2]中国石化石油物探技术研究院,南京211003

出　　处：《中国科技论文》2019年第1期9-13,共5页China Sciencepaper

基　　金：国家自然科学基金资助项目(41176077;41230318);国家高技术研究发展计划(863计划)资助项目(2013AA092501)

摘　　要：超虚折射重构利用多个稳相位点波场的叠加来提高初至信噪比。常规褶积型超虚折射由于不同偏移距对应的稳相位点个数不同,使得重构的超虚折射波场振幅严重不均衡。研究通过虚折射与原始波场的互相关重构得到相关型超虚折射,其振幅不均衡特征与褶积型恰好相反,两者叠加可以得到振幅均衡的超虚折射波场。通过数值模拟和实际数据验证了褶积型与相关型超虚折射叠加的优势,证实了超虚折射可以有效地提高初至波场的信噪比。尤其对远偏移距初至而言,初至波场的信噪比提高更加有效。研究指出重构道集波形变胖是由有效频带变窄造成的,并分析了坏道对重构波场的影响。Super-virtual refraction reconstruction can improve the first arrival’s signal-to-noise ratio based on the wavefield stack of multiple stationary-phase points. Due to the different stationary-phase point numbers corresponding to different offset, serious imbalance was found in the wavefield amplitude of conventional convolution super-virtual refraction. Correlating virtual refraction with original wavefield gets correlation super-virtual refraction. Its amplitude imbalance is just the opposite of convolution super-virtual refraction, so the stack of both can obtain balanced amplitude’s super-virtual refraction. Advantage of stack of convolution and correlation super-virtual refraction is verified by using numerical simulation and real data, confirming that super-virtual refraction can effectively improve signal-to-noise ratio of first arrival. It is more effective to improve signal-to-noise ratio of first arrival for far offset’s first arrival. This study shows that the fat reconstructed waves is caused by the narrowness of the effective frequency band, as well as analyzing the influence of the bad trace on the reconstructed wavefield.

关 键 词：地质资源与地质工程 超虚折射 振幅均衡 稳相位 初至 坏道 

分 类 号：P631[天文地球—地质矿产勘探]