METHOD OF SEALING A PRESSURE DROP ACROSS A DRILL BIT IN ROTARY APPLICATIONS

摘要

A method of sealing a pressure drop across a drill bit in rotary sealing applications consisting of the following described steps. Secure a first seal ring to an inner tubular member. Secure a second seal ring to an outer tubular member in which the inner tubular member is telescopically received. Urge the first seal ring and the second seal ring together in face to face engagement to form a mechanical seal. The mechanical seal has a first side and a second side. Provide a first clearance space between the first side of the mechanical seal and the outer tubular member. Provide a second clearance space between the second side of the mechanical seal and the inner tubular member. Provide an inflow passage between the inner tubular member and the outer tubular member communicating with one of the clearance spaces such that drilling fluids pumped down from surface pumps communicate with one of the sides of the mechanical seal. Provide an outflow passage from the other of the clearance spaces through the outer tubular member such that drilling fluids which pass through the engaged faces of the seal rings are diverted through the outflow passage to external of the outer tubular member.