基于压缩感知的地震弱反射融合重构技术研究及应用  

Research and application of seismic weak reflection fusion reconstruction technology based on compressed sensing

作　　者：李才 陈文雄 李芳 刁俊才 LI Cai;CHEN WenXiong;LI Fang;DIAO JunCai(Bohai Oilfield Research Institute,Tianjin Branch of CNOOC Ltd.,Tianjin 300459,China)

机构地区：[1]中海石油(中国)有限公司天津分公司渤海石油研究院,天津300459

出　　处：《地球物理学进展》2025年第1期387-397,共11页Progress in Geophysics

基　　金：中海石油(中国)有限公司“七年行动计划”重大科技专项课题(CNOOC-KJ-135ZDXM36TJ08TJ)资助.

摘　　要：渤中19-2构造位于渤中凹陷西南部,成藏背景有利,浅层已历经多轮次勘探,但仍未取得规模性发现.该区主要目的层明下段为曲流河沉积,河道纵横向变化快,砂体接触关系异常复杂,局部呈现地震弱反射假象,不符合砂体客观展布规律,影响连片砂体的描述.通过正演分析可知地震弱反射现象主要受到地层吸收衰减作用、目的层厚度、目的层物性、上覆地层速度、上覆地层结构及目的层与上覆地层距离等综合因素影响,原始地震资料振幅减弱且频带变窄.本文利用压缩感知最优化重建算法重构原始信号,将重构信号进行分频得到高频体与低频体,再将原始信号作为中频体输入,实现属性融合,最终得到融合数据体,该数据体主频提高,频带展宽,实现了地震弱反射的恢复.该方法能在不依赖测井资料的情况下,使恢复结果更符合真实地下情况,从而更加客观的反映出浅层砂体的展布规律,利于浅层岩性圈闭的刻画.The Bozhong 19-2 structure is located in the southwest of Bozhong Depression,with favorable accumulation background.The shallow layer has undergone multiple rounds of exploration,but no large-scale discovery has been made.The main target layer of the lower Ming section is deposited by the meandering river,and the longitudinal and transverse direction of the river changes rapidly,and the contact relationship of the sand body is unusually complex,which presents a weak seismic reflection artifact locally,which does not conform to the objective spreading rule of the sand body and affects the description of the continuous sand body.Through forward analysis,it can be seen that the seismic weak reflection phenomenon is mainly affected by the comprehensive factors such as the absorption and attenuation of the stratum,the thickness of the target layer,the physical properties of the target layer,the velocity of the overlying stratum,the structure of the overlying stratum and the distance between the target layer and the overlying stratum.The amplitude of the original seismic data is weakened and the frequency band is narrowed.In this paper,the compressed sensing optimization reconstruction algorithm is used to reconstruct the original signal,and the reconstructed signal is divided into high frequency body and low frequency body.Then the original signal is used as the input of the intermediate frequency body to realize the attribute fusion,and finally the fusion data body is obtained.The main frequency of the data body is improved,the frequency band is broadened,and the recovery of seismic weak reflection is realized.This method can make the recovery results more in line with the real underground situation without relying on logging data,so as to more objectively reflect the distribution law of shallow sand bodies,which is conducive to the characterization of shallow lithologic traps.

关 键 词：压缩感知 融合重构 地震弱反射 地震振幅 岩性圈闭 

分 类 号：P631[天文地球—地质矿产勘探] P738[天文地球—地质学]