The Reliability Evaluation of Threaded Connections in Challenging Drilling by Three-Dimensional Finite Element Analysis
The development of ultra-deep drilling and extended reach drilling present many critical challenges for the threaded connections. The reliability of threaded connections must be evaluated to ensure the structural and sealing integrity of drillstring in critical applications. Three-dimensional finite element analysis of threaded connections has been performed in this paper. Different types of loading composed of make-up torque, working torque, tension and bending loading are applied to the model. The makeup characteristics of threaded connections have been analyzed, and the reliability of threaded connections under severe conditions has been evaluated. The results show that von Mises stress distribution over threaded connections is highly uneven, tooth nearby two ends was bearing the most of load. It shows that ultra-deep drilling case is even more challenge than extend reach drilling case in the threaded connections, the reliability evaluation of threaded connections is important in those challenging drilling.