Open Access

ARTICLE

Analysis of the Microstructure of a Failed Cement Sheath Subjected to Complex Temperature and Pressure Conditions

by Zhiqiang Wu^1,2, Yi Wu², Renjun Xie², Jin Yang¹, Shujie Liu³, Qiao Deng^4,*

1 China University of Petroleum, Beijing, 102249, China
2 CNOOC Research Institute, Beijing, 100027, China
3Zhanjiang Branch, CNOOC Energy Technology & Services Limited, Zhanjiang, 524057, China
4 Yangtze University, Wuhan, 430100, China

* Corresponding Author: Qiao Deng. Email:

(This article belongs to the Special Issue: Meshless, Mesh-Based and Mesh-Reduction Methods Based Analysis of Fluid Flow in Porous Media)

Fluid Dynamics & Materials Processing 2023, 19(2), 399-406. https://doi.org/10.32604/fdmp.2022.020402

Received 24 November 2021; Accepted 08 February 2022; Issue published 29 August 2022

Abstract

One of the main obstacles hindering the exploitation of high-temperature and high-pressure oil and gas is the sealing integrity of the cement sheath. Analyzing the microstructure of the cement sheath is therefore an important task. In this study, the microstructure of the cement sheath is determined using a CT scanner under different temperature and pressure conditions. The results suggest that the major cause of micro-cracks in the cement is the increase in the casing pressure. When the micro-cracks accumulate to a certain extent, the overall structure of the cement sheath is weakened, resulting in gas channeling, which poses a direct threat to the safe production of oil and gas. A change in the casing temperature has a limited effect on the microstructure of the cement sheath.

---

Keywords

---