Acoustic evaluation of cementing quality using obliquely incident ultrasonic signals  

用斜入射超声波评价水泥胶结质量的方法研究(英文)

作　　者：段文星[1,2] 乔文孝[1,2] 车小花[1,2] 解辉 

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]北京市地球探测与信息技术实验室,北京102249 [3]中国石油集团测井有限公司,西安710077

出　　处：《Applied Geophysics》2014年第3期269-276,350,共9页应用地球物理（英文版）

基　　金：partially supported by the National Natural Science Foundation of China(Nos.11204380,11374371,61102102,and 11134011);National Science and Technology Major Project(No.2011ZX05020-009);Petro China Innovation Foundation(No.2013D-5006-0304);Chinese Petroleum Corporation Project(Nos.2011A-3903 and 2011B-4001)

摘　　要：Ultrasonic cement bond logging is a widely used method for evaluating cementing quality. Conventional ultrasonic cement bond logging uses vertical incidence and cannot accurately evaluate lightweight cement bonding. Oblique incidence is a new technology for evaluating cement quality with improved accuracy for lightweight cements. In this study, we simulated models of acoustic impedance of cement and cementing quality using ultrasonic oblique incidence, and we obtained the relation between cementing quality, acoustic impedance of cement, and the acoustic attenuation coeffi cient of the A0-mode and S0-mode Lamb waves. Then, we simulated models of different cement thickness and we obtained the relation between cement thickness and the time difference of the arrival between the A0 and A0′ modes.超声波水泥胶结质量评价测井是目前较为广泛使用的固井质量评价方法。将传统的脉冲回波技术与超声波斜入射方法相结合,可以形成评价固井质量的新技术。本文使用有限差分方法模拟研究了超声波斜入射时所激发出的波形特征与水泥性质以及胶结状况之间的关系。通过对三种常用水泥的数值模拟,得到了AO模式和SO模式Lamb波在不同胶结水泥及胶结情况下的声衰减系数;通过对不同厚度胶结水泥的数值模拟,得到了次生AO模式Lamb波和AO模式Lamb波的到时差与水泥性质及厚度的关系,并理论推导了水泥层厚度与时间差之间的关系,且从有限差分时域波形中提取的时间差与由理论公式计算结果能够较好的吻合。因此利用AO模式Lamb波到时及衰减信息可以在一定程度上评价水泥胶结状况及水泥厚度。

关 键 词：ULTRASONIC oblique incidence Lamb waves cementing evaluation 

分 类 号：P631.814[天文地球—地质矿产勘探]