弯曲型Lamb波传播特性与固井质量相关性研究

Relationship between propagation of the flexural Lamb wave and cementing quality

轻质水泥在油田固井中的广泛应用使得传统测井方式无法有效的对固井水泥胶结质量做出评价。为了研究新的可行的评价方法,本文采用传递矩阵方法对套管中传播的弯曲型Lamb波进行建模,并通过对所建模型进行数值计算研究了套管外水泥等介质的声学参数变化对弯曲型Lamb波衰减率的影响。数值计算的结果表明,弯曲型Lamb波的衰减率与水泥的声学参数以及水泥与套管的胶结状况有较强相关性,据此可对水泥与套管胶结状况进行评价。本文的计算结果与分析对弯曲型Lamb波在水泥胶结评价中的应用具有一定的参考意义。

Light weight cement is widely used in oil field cementing, resulting in traditional logging methods can＇t evaluate cement bond quality effectively. In order to study the new feasible evaluation method, the propagation of flexural lamb wave in casing pipe has been modeled by using the transfer matrix method in this paper. From numerical results, the influences of the acoustic parameters of the casing cement and other media on the flexural Lamb wave attenuation have been studied. The results of numerical calculations show that the attenuation rate of the flexural Lamb wave is strongly related to the acoustic parameters of the cement and the bonding condition. Based on this, the flexural Lamb wave can be used to evaluate the bonding condition. The results and analyses of this paper provide a guideline for the application of the flexural Lamb wave in the evaluation of cement bond quality evaluation.