基于零偏移距VSP的时变子波反褶积方法  

Time-varying wavelet deconvolution method based on zero-offset VSP data

作　　者：赵岩[1,2] 毛宁波 ZHAO Yan;MAO Ningbo(Key Laboratory of Exploration Technologies for Oil and Gas Resources,Ministry of Education(Yangtze University), Wuhan 430100,China;School of Geophysics and Oil Resources,Yangtze University,Wuhan 430100,China)

机构地区：[1]油气资源与勘探技术教育部重点实验室(长江大学),武汉430100 [2]长江大学地球物理与石油资源学院,武汉430100

出　　处：《岩性油气藏》2019年第6期88-94,共7页Lithologic Reservoirs

基　　金：国家自然科学基金项目“Q逆时偏移中的稳定性处理方法研究”(编号:41604094);油气资源与勘探技术教育部重点实验室(长江大学)开放基金资助项目“抗噪反Q滤波方法研究及应用”(编号:K2018-13)联合资助

摘　　要：提高地面地震数据分辨率的一种有效方法是从VSP数据中提取反褶积算子并将其应用于地面地震数据,然而,传统的VSP子波反褶积方法通常是在不考虑地震子波时变特性的情况下,提取固定反褶积算子,且由于地震子波是时变的,从VSP中提取一个子波反褶积算子应用于地面地震记录是不准确的,由此提出一种利用VSP数据提取时变子波反褶积算子的方法。该方法将零偏移距VSP数据的下行直达波作为单程VSP地震子波,利用地下介质的衰减函数将单程地震子波的振幅谱转换为双程地震子波的振幅谱,在最小相位的假设下,从时变子波振幅谱中获得时变反褶积算子,然后将算子应用于叠后地面地震数据。理论合成数据和实际地震数据证明了该方法可有效补偿振幅能量并可提高地震记录的分辨率。An effective way to improve the resolution of surface seismic data is to extract deconvolution operators from VSP data and use them for surface seismic data. However,the conventional VSP wavelet deconvolution method commonly extracts a fixed deconvolution operator without considering the time-varying characteristics of seismic wavelet. Since seismic wavelet is time-varying,it is not accurate to extract a wavelet deconvolution operator from VSP for surface seismic records. A method was proposed for extracting time-varying wavelet deconvolution operators by using VSP data. It takes the down-going direct wave of zero-offset VSP data as oneway VSP seismic wavelet,and converts its amplitude spectrum of the direct wave to that of two-way seismic wavelet by using the attenuation function of subsurface medium. Under the assumption of minimum phase,the time-varying deconvolution operator can be obtained from the amplitude spectrum,and then applied to poststack surface seismic data. Synthetic data and real data examples demonstrate that the proposed method can effectively compensate the amplitude energy and improve the resolution of seismic records.

关 键 词：时变子波 反褶积 叠后地面地震数据 零偏移VSP数据 

分 类 号：P631.44[天文地球—地质矿产勘探]