Tenaris has presented technical paper “Characterization of premium connections structural behavior under the presence of combined torsional and axial loads,” jointly written with Stress Engineering Services, at the 2022 SPE Annual Technical Conference and Exhibition (ATCE) in Houston, Texas, held on October 3-5 at the George R. Brown Convention Center.
An industry-first, this study offers a better understanding on how to ensure structural reliability and performance of premium connections, while contributing to define parameters to apply axial and torsional loads safely, minimizing the risk of compromising the structural integrity of the string.
This paper is especially relevant for unconventional wells. During casing installation in long horizontal sections, it is common to reach situations in which it is necessary to apply axial and torsional loads simultaneously in order to move a string that has become stuck, or define operative limits to avoid overloading the connection during installation.
“After pulling out, pushing downwards and twisting, it is frequent to find restrictions in the casing internal diameter that can generate interruptions and difficulties to install tools during operations. API TR 5C3 provides guidance on how to combine these loads for the pipe body, however until now there were no data points regarding premium connections,” says Santiago Grittini, Tenaris well design solutions director and one of the authors of the paper.
Based on finite element models and full scale test result analysis, the study includes a technical characterization of the response of premium connections to the simultaneous application of axial loads and torsional loads, supporting the development of a criteria to define safe working parameters for premium connections under combined axial and torsional loads, that would be more accurate than the safety margins currently used.
The paper covers from finite element analysis (FEA) exploration and simulation to final FST verification of premium threaded and coupled connections, such as TXP® BTC and TenarisHydril Wedge 461®. Using the same methodology, Tenaris has conducted numerical evaluations for slim line threaded and coupled connections, such as TenarisHydril Wedge 441®, and integral connections TenarisHydril Wedge 425® and TenarisHydril Wedge 625®, as well as full-scale testing results of the latter, which will be published in an upcoming paper.
“Having parameters to safely apply axial and torsional loads on premium connections provides operators with more room to maneuver when they need it most. This is another example of Tenaris’s contribution to safer and more efficient drilling and completion operations,” says Lucas Pigliacampo, Tenaris vice president oil and gas technologies.
To learn more about Tenaris products for unconventional wells visit: https://www.tenaris.com/en/products-and-services/octg/unconventional/