Simulation of Sealing Ability for Premium Connection Based on ISO 13679 CAL IV Tests

Abstract

To maintain the well integrity, the strength and sealing ability of premium connection should be in the safe scope. ISO 13679 is widely used for evaluating the ability of tubing and casing connection all over the world. Because of the disadvantage of experiment such as long period, high cost and high inquire on the facility, considering the convenience and universality of finite element method, as well as the contacting nonlinearity and material nonlinearity, three dimensional finite element model of a certain type premium connection is established with the consideration of helix angle. The loads exerted on the premium connection is the loads in series B test and thermal cycle test of ISO 13679. The distributions of Von Mises stress and contact pressure in various cases were studied. The results showed that the bending load has a great influence on the distribution of Von Mises stress and contact pressure for premium connection. The Von Mises stress and contact pressures on the sealing surface are smaller on the tension side and greater on the compression side. With increasing axial compression load, the contact pressures on the tension side are too small, which may arise sealing failure. The influence of temperature on the performance of premium connection can not be ignored when choosing or designing premium connections. Both the Von Mises stress and contact pressure decrease slightly during a period of thermal cycle. Although the performance of the premium connection is good in a period of thermal cycle, its performance in a long period should be evaluated. Finite element simulation can effectively simulate the ISO 13679 test procedure and obtain the stress and contact pressure distribution. It can be used as a reference for evaluating the performance of premium connections.