New developments in drilling and completion tubulars are necessary to drill and complete deeper, longer-reach and higher pressure wells in a cost-effective manner. Rotary shoulder style connections traditionally employed on drillpipe can offer significant advantages when coupled with high-pressure, gas tight metal-to-metal seal technology for completion and workover pipe, intervention risers and drillpipe for UBD applications. The paper provides details on how these critical applications can benefit from a new connection technology.
This paper presents the results of a two year comprehensive effort to design, test, and qualify third-generation rotary-shouldered connections for 20,000 psi internal and 10,000 psi external pressure service. ISO13679 testing methodologies for casing and tubing connections were modified to evaluate rotary shoulder connections pressure capabilities. Results from comprehensive finite element modeling and extensive laboratory testing designed to reproduce the harsh, aggressive loading modes and high pressures encountered in field use are presented.
Although drillpipe, drillpipe connections and drill stem materials represent mature technologies, innovations are being developed in these areas. The third generation gas-tight, double-shoulder connection presented here represents several advancements that address some of the challenges ahead.