Abstract: A seal assembly adapted for use in sealing two mating surfaces spaced apart by a gap is provided. The seal assembly includes a sealing element adapted to be located in a groove in one of the mating surfaces. A back-up ring assembly is provided which includes a first back-up ring made from a relatively soft material and a second back-up ring made from a relatively hard material. The first back-up ring includes a body with first and second sides, with one of a groove and an interlocking projection being located on the body along the second side. The second back-up ring includes a body with first and second sides, with the other of the groove and the interlocking projection being located along the first side.

Abstract: A backup shoe for a well packer provides high pressure sealing capability without requiring a large setting force or setting stroke of the packer. In a preferred embodiment, a backup shoe has an inner portion with a relatively thin cross-section and an outer portion with a relatively thick cross-section. Additionally, the inner portion has a pivot point between its ends. In a preferred embodiment of a packer utilizing the backup shoe, an element retainer axially contacts the inner portion adjacent its pivot point, and a seal element axially contacts an inner sloping surface formed on the outer portion.

Abstract: A hydrodynamically lubricated interference type rotary shaft seal suitable for environmental exclusion and high pressure lubricant retention which incorporates composite multiple modulus construction and a non-planar flexible environmental edge heel geometry which cooperate to resist high pressure extrusion damage while minimizing interfacial contact pressure and accommodating radial shaft motion.