Improvements in Rotary Seals for Downhole Motors in Geothermal Applications

摘要

The major limitation of downhole mud motors for geothermal well drilling as well as straighthole and oil well drilling is the bearing section. Reduced bearing life has been a direct result of the inability to seal lubricant in the bearing section. A reliable rotary seal is needed to extend bearing life and to allow high pressure drops across the drill bit for improved bottomhole cleaning and increased drilling rate. The endurance of high temperature rotary seal candidates is being measured in a full-scale laboratory seal tester capable of simulating the pressures and temperatures of geothermal well drilling. A description of the currently most successful high temperature seals and seal test results and findings are presented. (ERA citation 04:056355)