摘要
声波变密度测井利用5 ft*探头接收的地层波幅度评估固井第二界面水泥胶结质量,这是测井方法中为数不多的能对固井第二界面做出有效评价的测井方法。但是,由于地层岩性、孔隙结构和地层压实等因素会造成地层波到达时间和频率的不确定,评价软件从时域和频域都很难有效分辨并锁定地层波;同时,固井第一界面的胶结情况直接影响声波进入地层能量大小,也会影响固井第二界面的评价。利用裸眼井声波时差曲线,建立一种在时域上能随地层波波速变化的可动检测时窗,准确锁定地层波;并设置固井第一界面胶结校正系数,对可动时窗检测出的地层波幅度进行校正,消除第一界面胶结情况对地层波波幅造成的影响。实际应用表明,此方法在大多数情况下都能有效提升固井第二界面评价的准确率;但在某些地层中声波时差曲线为直线时,不论固井第一界面胶结如何,应利用地层波频谱特征判断是否为地层波,再进行固井第二界面的评价。该方法提升了声波变密度测井技术的应用潜力。
Acoustic variable density logging uses the formation wave amplitude received by the 5 ft probe to evaluate the cement bonding quality at the second cementing interface,which is one of the few logging methods that can effectively evaluate the second cementing interface.However,due to factors such as lithology,pore structure and compaction of the formation,the arrival time and frequency of formation waves are uncertain,making it difficult for evaluation software to effectively identify and lock formation waves in both time and frequency domains.At the same time,the bonding condition of the first cementing interface directly affects the energy of sound waves entering the formation,which also affects the evaluation of the second cementing interface.Based on the acoustic time difference curve of open hole,a movable detection time window which can change with formation wave velocity in time domain is established to accurately lock formation wave.The first interface cementation correction coefficient is set to correct the amplitude of formation wave detected by the movable time window,and the influence of the first interface cementation on the amplitude of formation wave is eliminated.The practical application shows that this method can effectively improve the evaluation accuracy of the second cementing interface in most cases.However,when the time difference curve of acoustic wave is straight in some formations,regardless of the cementation of the first cementing surface,the formation wave spectrum characteristics should be used to determine whether it is a formation wave,then the evaluation of the second cementing interface should be carried out.This method enhances the application potential of acoustic variable density logging technology.
作者
邱恩波
张伯新
戴月祥
邓兆元
陈敬
杨曦
田仕勇
同古力克
漆飞
陈煜
张旭
黄海涛
QIU Enbo;ZHANG Boxin;DAI Yuexiang;DENG Zhaoyuan;CHEN Jing;YANG Xi;TIAN Shiyong;Tonggulike;QI Fei;CHEN Yu;ZHANG Xu;HUANG Haitao(Development Division,Xinjiang Oilfield Branch,PetroChina,Karamay,Xinjiang 834000,China;Xinjiang Branch,China National Logging Corporation,Karamay,Xinjiang 834000,China)
出处
《测井技术》
2024年第6期854-860,共7页
Well Logging Technology
基金
中国石油天然气集团有限公司项目“水平井动态监测测井仪器现场试验”(2022ZS04)。
关键词
固井第二界面评价
声波变密度测井
水泥胶结
声波时差
检测时窗
evaluation of the second cementing interface
acoustic variable density logging technology
cement bonding
acoustic time difference
check time window
作者简介
第一作者:邱恩波,男,1981年生,高级工程师,从事油田开发工作。E-mail:qeb@petrochina.com.cn;通信作者:张伯新,男,1976年生,高级工程师,从事套管井测井解释工作。E-mail:zhangbx2006@cnpc.com.cn。
