High Pressure Washpipe Assemblies
The high pressure washpipe assemblies used in oil well drilling present difficult sealing challenges. With pressures up to 7,500 psi, and the large washpipe diameters and high speeds used in extended reach drilling, the PV values are extreme. Conventional washpipe packing sets typically only last a short while. Whenever a washpipe assembly fails, the bottom hole assembly (BHA) is typically tripped back into the casing shoe to avoid sticking during servicing of the washpipe. Since the BHA may have to be tripped as much as 4,000 meters each way, the required downtime for washpipe maintenance can result in excessively high drilling expenses.
One factor that sets Kalsi Engineering apart from other seal companies is our continual research to improve rotary seal performance, and to determine the best ways to employ seals in extreme pressure applications involving factors such misalignment, runout, and pressure-related component deformation. Our decades of experience in such matters allow us to provide detailed seal implementation advice to our customers, allowing them to achieve maximum rotary seal performance. Whether your application is a coaxial washpipe-based swivel or a side port swivel, we can help you take a systems approach to hardware design, achieving maximum rotary seal performance.
Chapter E4 of our seal handbook provides guidelines for how to best implement Kalsi sealing technology in what we believe to be the best mechanical arrangement for a high pressure washpipe assembly. The Key to the assembly is our patent-pending high pressure floating backup ring arrangement. Extensive developmental testing, with a 2.75 inch seal, shows that properly designed backup ring arrangements are capable of operating with 7,500 psi differential pressure for well over 1,000 hours at speeds up to 252 feet/minute. Pressure staging can be used to provide longer life, higher reliability, and higher pressure capacity.
Contact Kalsi Engineering for additional information, including seal selection and licensing arrangements.