Evaluation of Premium Threaded Connections Using Finite-Element Analysis and Full-Scale Testing

Abstract

Abstract The procedures developed by Exxon Production Research Company (EPR) for evaluating the performance of premium tubing and casing threaded connection designs using a combination of nonlinear finite element analysis (FEA) and full-scale physical tests are described in this paper. Over the past several years, EPR has developed advanced techniques for nonlinear FEA to accurately and efficiently calculate the stresses and deformations in threaded connections. Concurrently, EPR's Tubular Goods Test Facility (TGTF) was constructed to assist in verification of FEA models and to conduct full-scale physical tests. Evaluation procedures have been developed that are based on using the combined results of state-of-the-art nonlinear FEA and rigorous full-scale physical tests. Finite element models are "linked" to full-scale tests to form the tools for evaluating threaded connections. Several years of experience in implementing these two evaluation tools together have revealed a unique and valuable synergism between analytical models and physical tests. EPR's evaluation philosophy is to use knowledge gained from advanced accurate FEA to test fewer connections with greater confidence in the results.