Abstract: A fluid assembly comprising a first part (28) and a second part (30) which interact by relative linear movement therebetween. A groove (40) extends around the circumference of the cylindrical interacting surface (36) of the first part (38) and a seal (50) is situated within the groove (40). The seal (50) has a radial face (64) which converts from a concave profile to a flat profile flush with the groove's root side (54) upon interface with the interacting surface (38) of the second part (30). The seal (50) also has axial faces (62) which each assume a more pronounced concave profile upon such interfacing, the concave profiles forming cavities (68) which, when filled with fluid, urge the radial seal face (64) and radial seal face (66) towards the groove's root side (54) and the interacting surface (38) of the second part (30).

Abstract: Method of sealing one or more threaded connections between ends of a pair of tubular members configured to be rotatably threadably engageable. One of the members as an externally-threaded portion, with the other one having an internally-threaded portion. One of the threaded portions has a radial groove formed therein which is configured to receive a seal ring for sealing the connection. The groove of the one portion defines a void with the other portion, with the seal ring being compressed into the void by the engagement of the threaded ends of the members. The method involves determining a deformed axial cross-sectional geometries of the ends, mathematically revolving the deformed axial cross-sectional geometries to generate a corresponding solid of revolution, calculating the volume of the void by subtracting the open of the solid volumes from the other, and sizing the seal ring to overfill the void by a specified amount.

Abstract: A modified API Buttress threaded casing connection is disclosed for use in drilling oil and gas wells in lieu of using conventional drill pipe. The coupling threads only are multiple tapered yet can be mated with standard API Buttress pin threads having a single taper. The coupling is also shortened to permit abutment of the mating pins at the center of the coupling and can be further enhanced with an integral, sacrificial wear sleeve on one end of the coupling.