The high pressure washpipe assemblies used in oil well drilling are subjected to difficult sealing conditions. A conventional washpipe packing fails in only a few hours when subjected to 6,000 psi or greater mud pressure. Replacement of the failed washpipe packing assembly typically requires the bottom hole assembly to be tripped back into the casing which can result in significant downtime.
Kalsi Engineering has developed two technologies that when combined provides a robust sealing solution to high pressure washpipe assemblies.
Plastic Lined Kalsi Seals constructed of -303 material installed in our patented backup ring hardware arrangement have been rotary tested for 1,000 hours at 7,500 psi. The floating washpipe was rotating at 240 feet/minute with 7,500 to 7,800 psi (51.71 to 53.78 MPa) lubricant pressure using an ISO 150 viscosity grade lubricant maintained at 130°F (54.4°C). The test simulates the surface speed of a 4.875” (123.83mm) OD washpipe rotating at 200 RPM at the anticipated temperature of the drilling mud. The seals were in excellent condition at the conclusion of the 1,000 hour test, as shown below, and could have kept running for much longer.