一种基于压缩感知理论的强反射地震信号消减方法  

A strong seismic energy reduction method under compressed sensing

作　　者：李胜军[1] 高建虎[1] 张繁昌[2] 贺东阳 桂金咏[1] LI Shengjun;GAO Jianhu;ZHANG Fanchang;HE Dongyang;GUI Jinyong(PetroChina Research Institute of Petroleum Exploration&Development-Northwest,Lanzhou 730020,China;School of Geosciences,China University of Petroleum(East China),Qingdao 266580,Shandong,China)

机构地区：[1]中国石油勘探开发研究院西北分院,兰州730020 [2]中国石油大学(华东)地球科学与技术学院,山东青岛266580

出　　处：《岩性油气藏》2023年第4期70-78,共9页Lithologic Reservoirs

基　　金：中国石油股份公司前瞻性基础性战略性技术攻关项目“复杂气藏地震识别与预测技术研究”(编号:2021DJ0606);中国石油勘探生产分公司科技项目“薄储层全频处理方法研究与目标精细刻画技术攻关实验”(编号:2022KT1503)联合资助。

摘　　要：基于压缩感知理论,根据强、弱反射之间子波干涉机理,提出了逼近任意强反射波形的动态字典强反射分解方法和基于屏蔽函数的强反射消减方法。利用数值模型和强反射波形横向变化大的物理模型验证了该方法的有效性,并在川中古隆起构造带中部二叠系茅口组二段进行了实际应用。研究结果表明:(1)相比常规去强反射方法,基于屏蔽函数的强反射消减方法处理后,地震同相轴横向连续性更好,强反射同相轴消减得更彻底,被强反射屏蔽的块状砂体弱反射突显出来,同时该方法对层位的依赖低,不需要准确的强反射层位数据,可将时窗范围内的强反射一次处理完成。(2)基于屏蔽函数的强反射消减方法在砂体与强反射层距离小于λ(波长)且大于λ/4时,消除效果较好,强反射可完全去除,弱反射完全显现;当砂体与强反射层距离小于λ/4时,消除效果较差,砂体与强反射层距离越小(小于λ/8时),效果越差。(3)该方法在川中古隆起构造带中部二叠系茅口组二段应用效果较好,储层距离强放射层小于λ/4的井区,储层弱反射得以显现,储层距离强放射层大于1/4波长的井区,储层响应得到增强。Based on the compressive sensing(CS)theory and the wavelet interference mechanism between strong and weak reflections,a dynamic dictionary strong reflection decomposition method by approximating arbitrary strong reflection waveforms and a strong reflection reduction method based on shielding function were proposed.The validity of the methods was verified using numerical models and physical models with large lateral variations of strongly reflected waveforms.The methods have been practically applied in the second member of Permian Maokou Formation in the central uplift tectonic zone of central Sichuan Basin.The results show that:(1)Compared with the conventional de-strong reflection method,the strong reflection reduction method based on shielding function has better lateral continuity of the seismic event,the strong reflection event is more thoroughly reduced,and the weak reflection of the blocky sand body shielded by the strong reflection is revealed.At the same time,the method has low dependence on the horizon and can process the strong reflection within the time window at one time without accurate strong reflection horizon data.(2)The strong reflection reduction method based on shielding function has a better elimination effect when the distance between the sand body and the strong reflection layer is less thanλ(wavelength)and greater thanλ/4.The strong reflection can be completely removed and the weak reflection is completely revealed.When the distance between the sand body and the strong reflection layer is less thanλ/4,the elimination effect is poor.When the distance between the sand body and the strong reflection layer is less thanλ/8,the elimination effect is worse.(3)This method is better applied in the second member of Permian Maokou Formation in the central uplift tectonic zone of central Sichuan Basin.The weak reflection of the reservoir is revealed when the distance between the reservoir and the strong reflection layer is less thanλ/4.The reservoir response is enhanced when the distance between t

关 键 词：强反射消减 地震信号分解 压缩感知 屏蔽函数 动态字典 信号增强 储层预测 

分 类 号：TE319[石油与天然气工程—油气田开发工程] P631.4[天文地球—地质矿产勘探]