# Analysis of Bonding Defects in Cementing Casing Using Attenuation Characteristic of Circumferential SH Guided Waves

## TL;DR

This paper introduces a new method using guided waves to detect bonding defects in cemented casing, enabling non-destructive testing and evaluation.

## Contribution

A novel numerical method combining state matrix and Legendre polynomial techniques is proposed for analyzing bonding defects in cementing casing.

## Key findings

- The amplitude of SH guided waves correlates with the size of bonding defects through the attenuation coefficient.
- An experimental platform successfully detects bonding defects of different sizes in cementing casing.
- Circumferential SH guided waves show attenuation characteristics due to cement cladding, aiding defect detection.

## Abstract

What are the main findings?
Based on the state matrix and Legendre polynomial hybrid method, a new numerical method is presented for the investigation of the propagation characteristic of C-SH waves in cementing casing.The relationship between the amplitude of SH guided waves and the size of the bonding defects is established through the attenuation coefficient.The size of the bonding defects can be experimentally predicted by the attenuation distribution curve.

Based on the state matrix and Legendre polynomial hybrid method, a new numerical method is presented for the investigation of the propagation characteristic of C-SH waves in cementing casing.

The relationship between the amplitude of SH guided waves and the size of the bonding defects is established through the attenuation coefficient.

The size of the bonding defects can be experimentally predicted by the attenuation distribution curve.

What are the implications of the main findings?
It provides a numerical analysis method and experimental prediction basis for the detection of bonding defects in cemented casing.

It provides a numerical analysis method and experimental prediction basis for the detection of bonding defects in cemented casing.

Circumferential guided wave detection technology can serve as an alternative method for detecting casing bond defects. Due to the presence of the cement cladding, the circumferential SH guided waves transmit shear waves into the cement cladding as they propagate in the cementing casing, which cause the circumferential SH guided waves to show attenuation characteristics. In this study, the cementing casing structure was considered as a steel substratum semi-infinite domain cemented cladding pipe structure, and the corresponding dispersion and attenuation characteristics of circumferential SH guided waves were numerically solved based on the state matrix and Legendre polynomial hybrid method. In addition, a finite element simulation model of cementing casing was established to explore the interaction between SH guided waves and bonding defects. The relationship between the amplitude of SH guided waves and the size of the bonding defects was established through the attenuation coefficient. Moreover, an experimental platform for cementing casing detection is constructed to detect bonding defects of different sizes and to achieve the acoustic analysis of cementing defects in cementing casing, which provides a research path for the non-destructive testing and evaluation of bonding defects in cementing casing.