TY - EJOU
AU - Zhao, Lingyun
AU - Yang, Heng
AU - Wei, Yuanlong
AU - Bu, Yuhuan
AU - Jing, Shaorui
AU - Zhou, Peiming
TI - Integrity and Failure Analysis of Cement Sheath Subjected to Coalbed Methane Fracturing
T2 - Fluid Dynamics \& Materials Processing
PY - 2023
VL - 19
IS - 2
SN - 1555-2578
AB - Perforation and fracturing are typically associated with the development of coalbed methane wells. As the cement sheath is prone to failure during this process, in this work, the effects of the casing pressure, elastic modulus of the cement, elastic modulus of the formation, and casing eccentricity on the resulting stresses are analyzed in the frame of a finite element method. Subsequently, sensitivity response curves of the cement sheath stress are plotted by normalizing all factors. The results show that the maximum circumferential stress and Mises stress of the cement sheath increase with the casing internal pressure, elastic modulus of the cement and casing eccentricity. As the elastic modulus of the formation increases, the maximum circumferential stress of the cement sheath decreases, and its maximum Mises stress increases slightly. The cement sheath undergoes tensile failure during coalbed methane fracturing. The stress sensitivity of the cement sheath to the influential parameters is in the following order: casing internal pressure > elastic modulus of cement sheath > casing eccentricity > elastic modulus of formation.
KW - Coalbed methane fracturing; finite element method; cement sheath integrity; sensitivity analysis; failure analysis
DO - 10.32604/fdmp.2022.020216