Patent ID: 10180059

Abstract:
A telemetry tool comprising a pulser assembly, a primary seal, a fluid pressure pulse generator and a secondary seal. The pulser assembly comprises a housing and a driveshaft extending out of an opening in the housing. The primary seal surrounds and seals against the driveshaft to seal the opening in the housing. The fluid pressure pulse generator comprises a stator with a bore therethrough configured to fixedly attach to the housing or to a drill collar surrounding the fluid pressure pulse generator, and a rotor fixedly attached to the driveshaft. The driveshaft and rotor rotate relative to the fixed stator to generate pressure pulses in mud flowing through the fluid pressure pulse generator. The secondary seal is seated in the stator bore and surrounds and seals against a portion of the driveshaft extended out of the housing or a portion of the rotor to reduce the amount of mud, grit and debris impinging on the primary seal which could otherwise cause wear or damage the primary seal.