Failure mechanism and influencing factors of cement sheath integrity under alternating pressure

作     者：Kuan-Hai Deng Nian-Tao Zhou Yuan-Hua Lin Yan-Xian Wu Jie Chen Chang Shu Peng-Fei Xie 

作者机构：State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University)ChengduSichuan610500China Engineering Technology Research InstitutePetroChina Xinjiang Oilfield CompanyKaramayXinjiang834000China CNPC Xibu Drilling Engineering Company LimitedUrumqiXinjiang830000China Engineering Technology Research InstitutePetroChina Southwest Oil&Gas Field CompanyChengduSichuan610066China 

出 版 物：《Petroleum Science》 (石油科学（英文版）)

年 卷 期：2023年第20卷第4期

页      面：2413-2427页

核心收录：

学科分类：0820[工学-石油与天然气工程] 082001[工学-油气井工程] 08[工学] 

基　　金：Research work was financed by the National Natural Science Foundation of China(No.52074232) Sichuan Science and Technology Program(No.2022NSFSC0028,No.2022NSFSC0994).Without their support,this work would not have been possible 

主　　题：Casing-cement sheath-formation system Mechanical model Matching relationship Cement sheath integrity Critical range Mechanical parameters 

摘      要：The failure of cement sheath integrity can be easily caused by alternating pressure during large-scale multistage hydraulic fracturing in shale-gas *** elastic-plastic mechanical model of casing-cement sheath-formation(CSF)system under alternating pressure is established based on the Mohr-Coulomb criterion and thick-walled cylinder theory,and it has been solved by MATLAB programming combining global optimization algorithm with Global *** failure mechanism of cement sheath integrity is investigated,by which it can be seen that the formation of interface debonding is mainly related to the plastic strain accumulation,and there is a risk of interface debonding under alternating pressure,once the cement sheath enters plasticity whether in shallow or deep well *** matching relationship between the mechanical parameters(elastic modulus and Poisson s ratio)of cement sheath and its integrity failure under alternating pressure in whole well sections is studied,by which it has been found there is a“critical rangein the Poisson s ratio of cement *** the Poisson s ratio is below the“critical range,there is a positive correlation between the yield internal pressure of cement sheath(SYP)and its elastic ***,when the Poisson s ratio is above the“critical range,there is a negative *** elastic modulus of cement sheath is closely related to its Poisson s ratio,and restricts each *** and reasonable matching between mechanical parameters of cement sheath and CSF system under different working conditions can not only reduce the cost,but also protect the cement sheath integrity.