微测井和地震资料联合的近地表Q反演方法及应用  

Near surface Q inversion method combined with micro-log and seismic data and its application

作　　者：刘立彬 田坤[2] 张学涛[2] LIU LiBin;TIAN Kun;ZHANG XueTao(Sinopec Shengli Oilfield Branch Oil and Gas Exploration Management Center,Dongying 257022,China;Shengli Geophysical Research Institute of Sinopec,Dongying 257022,China)

机构地区：[1]中国石化胜利油田分公司油气勘探管理中心,东营257022 [2]中国石化胜利油田分公司物探研究院,东营257022

出　　处：《地球物理学进展》2023年第4期1625-1636,共12页Progress in Geophysics

基　　金：国家自然科学基金(42074133);胜利油田科技攻关项目(YKW2105)联合资助。

摘　　要：近地表吸收衰减是影响地震资料分辨率的重要因素,而求取准确的近地表品质因子Q值并进行补偿是解决这一问题的关键.为提高近地表Q建模精度,提出了一种利用微测井和地面地震数据初至的近地表Q反演方法.首先采用单尺度Gabor变换,对微测井初至进行时频谱求取,并基于频谱比法的思想求取微测井点处的Q值,然后对地面地震初至进行拾取和等效衰减量求取,以地面地震初至波的等效衰减量为匹配目标,建立微测井Q约束的目标函数,通过反演求解实现近地表Q建模.本方法能够同时借助微测井资料的纵向高精度和地面地震的横向高采样率,建立较为准确合理的近地表Q模型.对实际资料近地表Q建模与偏移补偿测试结果的分析表明,本文方法是正确和有效的.The absorption and attenuation of seismic waves by near surface media is very serious.Therefore,eliminating the influence of absorption and attenuation of surface media on seismic signals can improve its high-frequency energy,widen the effective band width,and greatly improve the resolution of seismic data.Q compensation is an effective means to eliminate the influence of formation absorption and attenuation on seismic signals,and obtaining accurate near surface quality factor Q is the key to eliminate the influence of near surface absorption and attenuation and improve the resolution of seismic data by using Q compensation method.In order to improve the accuracy of near surface Q modeling,a near surface Q inversion method using micro-log and surface seismic data is proposed.Firstly,the single-scale Gabor transform is used to calculate the time frequency spectrum of the first break of micro-log,and the Q value at the micro-log point is calculated based on the idea of spectrum ratio method.Then,the surface seismic first break is picked up and the equivalent attenuation is calculated.On the basis of near surface velocity model and ray tracing,taking the equivalent attenuation of the ground seismic first break as the matching target,the objective function of micro-log Q constraint is established,taking micro-log Q value as hard constraint,and the near surface Q modeling is realized through inversion.This method can establish a more accurate and reasonable near surface Q model with the help of the vertical high precision of micro-logging data and the horizontal high sampling rate of surface seismic at the same time.The analysis of near surface Q modeling and migration compensation test results of actual data shows that the method in this paper is correct and effective.The established Q model is more in line with the actual situation,and the migration result after compensation is also improved.

关 键 词：近地表 Q模型 微测井 初至波 Q偏移 

分 类 号：P631[天文地球—地质矿产勘探]