31 Hydrodynamic Wash Pipe National Oilwell and Kalsi Engineering Company have developed a wash pipe packing system that dramatically improves the economics of drilling at high pressure. The 7500 PSI Hydrodynamic Washpipe System* (US and Foreign Patents Pending) substantially increases the service life of wash pipe packing in high pressure applications up to 5 times that of conventional packing, resulting in: Reduced Rig Down Time by up to 75%. Reduced Safety Risk (due to fewer change outs). Cleaner Well Bores (with larger diameter bore). Faster Penetration Rates (due to allowing higher RPM). Reduced Well Costs Overall. The Hydrodynamic Washpipe System is currently available on National Oilwell power swivels with 4" and 5" openings and can be retrofitted to comparable top drives. The new system is also available with conventional National Oilwell Swivels. In standard drilling conditions with mud pressure up to 3,000 PSI, conventional wash pipe and packing lasts up to 800 hours. However, as pressure rises above 5,000 PSI, conventional wash pipe systems fail in under 100 hours - and often in under 50 hours as the pressure rises incrementally. The Hydrodynamic Washpipe System is capable of operating at pressures up to 7,500 PSI with markedly longer service life, allow- ing for fewer operation suspensions and decreasing the risk to crew members who must perform the change out. In addition, with the redundant lubricator circuit, downtime maintenance can be sched- uled at a more convenient operation rather than shutting down drilling and pulling out of the hole to replace a failed seal. IMPROVING THE PROCESS In conventional packing arrangements, each seal does all of the work on its own until it fails.  The work effort is then transferred over to the next seal.  In the hydrodynamic packing box, each seal is doing an equal share of the work from the very beginning, resulting in a longer lasting seal. The Hydrodynamic Washpipe System reduces the pressure drop across the wash pipe seals by pumping pressurized oil into the cavity behind the seal.  The pressure on the back side of the seal is actually higher than the pressure on the drilling fluid side of the seal.  The seal itself is designed to "float" on the oil, much as a car's tires will hydroplane on a wet road.  The result is a slight amount of oil seeping underneath the seal and ensuring that drilling fluid does not come into contact with and degrade the seal itself.  The service life of the wash pipe packing is actually extended by the judicious application of a "leak".