Analysis of wellbore seal integrity under cyclic loading conditions

Abstract

Sealing integrity of wellbore under cyclic load is one of the key issues to ensure production safety during the development of oil and gas fields. In this paper, the sealing integrity of casing and cement ring under cyclic load is studied by means of physical experiment and finite element analysis. The actual working conditions of casing under cyclic load were simulated by self-made test device, and the casing-cement ring-formation 3D model was established with Abaqus finite element software, and the sealing integrity was numerically simulated. The results show that the increase of cyclic load has little effect on the plastic deformation and bearing performance of the casing, but with the increase of the number of load cycles, the cement ring is subjected to circumferential stress, and the displacement of the cement ring with small elastic modulus is larger, which can lead to the poor sealing property of the cementing surface between the casing and the cement ring.