This presentation is about 17 minutes in duration. It is my presentation given at the 2025 SIMULIA Americas Users Conference. It describes two fracture analysis methods in Abaqus to evaluate the desired fracture deployment of a downhole well plug tool.

Abstract

Fracture mechanics analysis is often applied to assess damaged equipment using Fitness-for-Service assessment methods to avoid a failure due to the presence of a crack. In contrast, this presentation gives a fracture analysis comparison of a downhole tool that is intended to fracture for deployment. The analyses confirm the fracture occurs when needed. In the tool, an actuator applies the axial force to move two parts together. A cone shaped segment is in sliding contact with the sleeve inner surface. As the actuator moves the cone into the sleeve, the imposed radial expansion of the sleeve causes a circumferential stress leading to the sleeve fracture. The actuator force versus displacement trend from the Abaqus results gives the peak force when fracture starts and gives the sustained force to complete the deployment fracture. The analysis results ensure the actuator can provide the needed force. 

Two fracture analysis methods were used in Abaqus: (1) a cohesive element progressive damage as the fracture initiates and grows, and (2) focused crack meshes to compute J-integral and stress intensity K at several crack lengths. The progressive damage takes advantage of the Abaqus option to define the traction-separation trend by defining the total fracture energy. The fracture energy was related to the fracture toughness used with the focused mesh models. The Abaqus damage model commands used to create these models will be reviewed. The models and results from these two analyses are compared and discussed.