Modeling of stress state of a perforated cement sheath in a production well

Modeling of stress state of a perforated cement sheath in a production well is performed. Long-term well operation is considered. The slightly compressible fluid flow model is used to calculate the pore pressure of a fluid. The linear-elastic body model and finite volume method with multipoint stress approximation are used to calculate the stress state of the cement sheath and production casing. The numerical model was verified by comparing the calculation results with a calculation in the Fenics open-source computing platform. It is shown that the maximum von Mises stress value falls on the perforation zone at the junction of the cement sheath and production casing. Stresses are shown to slightly decrease during long-term well operation. It is also shown that an increase in the Young's modulus of the production casing leads to a decrease in the von Mises stress in the cement sheath. (paper)