中国石油大学学报（自然科学版）2017，Vol.41Issue(5)：94-101,8.DOI:10.3969/j.issn.1673-5005.2017.05.011
固井界面微环隙产生机制及计算方法
An assessment method for occurrence of micro-annular fractures on cementing interfaces of oil and gas well casing
摘要
Abstract
The generation and development of micro-annular fractures on cementing interface of oil and gas well casing during long-term production were investigated via simulation experiments, and the bonding strength of cementing interface was meas-ured in the experiments. Based on the experimental results, a theoretical assessment method of the micro-annular fracture was developed, and a good agreement between the experimental results and modeling was observed. The results show that an excessive inner casing pressure can lead to plastic deformation of cement sheath, while a tensile stress can be subjected on the cementing interface when the inner pressure is reduced during the casing pressure unloading process. The magnitude of the interfacial bonding strength is of 0. 1 MPa as it was measured in the experiments, and micro-annular fractures can appear at the cementing interfaces when the tensile stress is sufficient high to overcome the bonding strength. The larger the inner casing pressure, the higher probability for the micro-annular fractures to occur during pressure surge, and the larger the frac-tures. Micro-annular fractures are more likely to appear at the first casing-cement interface due to a higher tensile stress even if the bonding strength at two interfaces is the same.关键词
井筒完整性/微环隙/仿真试验/理论计算/黏结力Key words
well integrity/micro-annular fracture/simulation experiment/theoretical calculation/bonding strength分类
能源科技引用本文复制引用
赵效锋,管志川,史玉才,李涛,廖华林,蒋金兴,孙宝江..固井界面微环隙产生机制及计算方法[J].中国石油大学学报（自然科学版）,2017,41(5):94-101,8.基金项目
国家自然科学基金项目(51674284) （51674284）
中央高校基本科研业务费专项(R1502039A, 16CX06035A) （R1502039A, 16CX06035A）
