The Future of Environmental Riserless Drilling: Dope Free Drill Pipe Connections Using Thread Saver Technology

Abstract

Threaded connections which employ a metallic “thread saver” for OCTG in lieu of a thread compound are potentially valuable for the drilling industry because they offer a fast make-up process and an environmentally friendly method of making secure threaded connections without damaging threads. Using a thread saver to protect the tool joint thread is not a new idea, but new developments in materials technology combined with a better understanding of the makeup process appear to offer a new solution for compound-free drill pipe connections. The paper presents the latest tests conducted on NC38 drill pipe connections using thread savers fabricated from a CuBe alloy. Different tempers of the alloy and different thread saver surface coatings were tested. The results reported are the data from the first series of more than 60 tests that were carried out at the Technical University of Clausthal. The tests were designed to provide a characterization of the mechanical behavior of the connection process using the thread saver. Data from the tests is compared to similar data previously developed for the more-familiar processes which use thread compound. The results show the new technology is viable and may be used for heavy duty applications such as drill pipe and drill collar connections. Additionally, a short review of the thread saver history for the drilling industry is presented. Results suggest some important applications for the thread saver technology may be in riserless drilling or in scientific drilling such as the Integrated Ocean Drilling Program. A reliable “dope-less” connection technology is particularly valuable for operations where the adverse impact of environmental contamination by stray thread compounds is potentially higher than in some other operations.