Numerical Investigation of the Dynamic Response and Potential Damage of Cement Sheaths Under Perforation Shock Loading

Perforation shock loading may damage the cement sheath and impair wellbore sealing, raising concerns about deep-water well completion. With this engineering background, a three-dimensional wellbore model was developed to investigate the transient mechanical response of the cement sheath. Residual explosive energy was represented by an equivalent explosion source. The Holmquist–Johnson–Cook model was adopted for the cement sheath, and auxiliary stress reference levels were introduced to compare stress concentrations. The results show that stress concentrates at the inner wall of the perforation hole, followed by attenuation and oscillation. Increasing the elastic modulus from 4 to 12 GPa raises the residual von Mises stress from 17.01 to 37.01 Mpa, whereas increasing Poisson’s ratio from 0.18 to 0.26 reduces it from 21.98 to 17.99 Mpa. Density increases peak stress by 78.31% but produces a smaller residual stress variation than elastic modulus within the investigated ranges. The calculated stress concentration locations are qualitatively consistent with published experimental damage observations. Within the investigated parameter ranges, lower elastic modulus and higher Poisson’s ratio are associated with reduced stress concentration. These findings provide a mechanical basis for cement sheath material selection under perforation loading and may inform further studies of wellbore integrity in deep-water applications.