基于小波变换定量评价固井质量第Ⅱ界面  

Quantitative Cementing Quality Evaluation of Second Interface Based on Wavelet Transform

作　　者：王长江 钱建设 李长文 申晓娟 于清秀 陈鸿傲 WANG Changjiang;QIAN Jianshe;LI Changwen;SHEN Xiaojuan;YU Qingxiu;CHEN Hongao(China Petroleum Logging CO. LTD. , Xi＇an, Shaanxi 710077, China;Tianshi Energy CO. LTD, Panjin, Liaoning 124000, China;Logging Company, Henan Petroleum Engineering CO. LTD. , Nanyang, Henan 473000, China)

机构地区：[1]中国石油集团测井有限公司,陕西西安710077 [2]天时集团能源有限公司,辽宁盘锦124000 [3]河南石油工程有限公司测井公司,河南南阳473000

出　　处：《测井技术》2018年第1期98-101,共4页Well Logging Technology

基　　金：国家科技重大专项大型油气田与煤层气开发(2016ZX05031-1-2-4)

摘　　要：使用小波变换法对变密度全波信号进行时频分析技术,通过试验证明Moret小波函数适合变密度地层波计算分析,可以计算地层波的强度、位置,定量评价第Ⅱ界面固井质量。经过小波变换后,把变密度信号序列分解为不同频率、幅度、位置(时刻)的小波集,利用符合地层波特征的小波集可以重构出地层波,小波变换准确重构出了地层波,其位置、幅度效果都十分理想,前端套管波信息保持了原状,后端泥浆波信息得到复原,完全可以满足固井质量评价要求。在第Ⅰ界面胶结中等或良好的情况下,地层波越强(能量、幅度大),第Ⅱ界面胶结越好。小波变换重构地层波效果比较好,地层波到时前的套管波信息被全部滤掉,为用重构地层波信息,更准确评价固井第Ⅱ界面提供了良好基础。This paper proposes the use of variable density,a full-wave signal and time-frequency analysis of wavelet transform,Tests proved Moret wavelet analysis is right for variable density layer wave computation.The strength and location of the formation wave can be calculated,thusⅡinterface cementing quality can be quantitatively evaluated.After the wavelet transform,the variable density signal sequence is decomposed into different frequency,amplitude,position（time）of the small wave shoaling,and the small wave shoaling consistent with layer wave feature can be used to reconfigure the layer wave,and wavelet transform can also reconfigure the layer wave accurately,its position and the amplitude are very good,the information of front casing wave maintains the status quo,the information of back end mud arrival is restored,which can fully meet the requirements of primary cement evaluation.The cementation of Ⅰ interface is medium or well,the layer wave is more stronger（energy and amplitude are more larger）,Ⅱcemented interface is better.The result using wavelet transform to reconfigure layer wave is very good,the front casing wave＇s information of which before the layer wave arrival is completely filtered out,and this provides a good basis for more exactly evaluated cementationⅡinterface by using the reconfigured layer wave＇s information.

关 键 词：测井解释 小波变换 声波变密度测井 地层波重构 固井质量 定量评价 

分 类 号：P631.84[天文地球—地质矿产勘探]