Abstract: A packer for effecting steam treatment of a production formation of a subterranean well comprises an insulated mandrel which is slidably inserted within the bore of an inner tubular body assembly. An outer operative tubular assembly surrounds the inner assembly and mounts a plurality of drag blocks, upper and lower cone elements, a plurality of radially displaceable slips cooperating with the upper and lower cone elements, and an outer packing element fabricated by an assemblage of high temperature resistant, non-resilient seal elements formed primarily of graphite. An inner packing element is provided in the inner tubular body assembly utilizing additional high temperature resistant, non-resilient seal elements formed primarily of graphite, which sealingly engages the insulated mandrel.

Abstract: A concentric insulating tubular conduit member for use in forming a conduit string, such as a tubing string in a subterranean well, is disclosed. Each individual concentric conduit comprises an outer tubing and an outwardly flared inner tubing welded to the outer tubing at the ends. Insulation may be contained within the sealed annular cavity between the inner and outer tubing members and between inner and outer coupling members at the juncture between adjacent tubing sections. Centralizers are positioned in the annular cavity between the inner and outer tubular members at one or more points between the ends of each conduit section. Each centralizer has an axially extending cylindrical section and a radial support section in contact with one of the tubular members.

Abstract: A concentric insulating tubular conduit string, including one or more joints with concentric tubular members is disclosed. A concentric walled joint of the type disclosed herein is especially adapted to form a separation joint when incorporated in the tubular string. An insulating conduit incorporating one or more integral separation joints of the type disclosed could be employed for the delivery of a heated fluid, such as steam, through the conduit to the producing formation therebelow. The inner and outer tubular members of the separation joint may be prestressed in tension and compression between axially spaced coupling members used to join the separation joint to the rest of the tubular conduit. A hermetically sealed annular insulating cavity is formed between the inner and outer tubular members. This joint can be separated by merely severing the tensile loaded tubular member and upon severance of this separation joint the conduit extending thereabove can be removed from a subterranean well.

Abstract: A packer adapted for thermal applications to provide sealing integrity between the tubing and casing in a subterranean well is disclosed in combination with a tubing anchor seal assembly for providing secured sealing integrity between the tubing and the seal bore of the packer. The tubing anchor seal assembly comprises an inner mandrel attached to the tubing string. Annular seals are disposed on the exterior of the mandrel. A latch prevents upward movement of the tubing anchor seal assembly relative to the packer, while downward movement is prevented by abutting shoulders. A concentric sleeve engages the seals and radial protrusions on the mandrel transmit longitudinal force to the seals trapped against the sleeve to energize the seals which need not be elastomeric.

Abstract: A seal assembly employing a thermoplastic sealing element, such as polytetrafluoroethylene, for maintaining sealing integrity between inner and outer concentric tubular members is disclosed. Axial extrusion of the sealing element through a constricted passage into a cavity adjacent the surface of one of the tubular members is allowed when the sealing element expands due to increased heat or pressure. Axial contraction through this same passage serves to maintain sealing integrity in the vicinity of this passage. The performance of the contracting sealant is improved during a cooling cycle by utilizing a cylindrical seal ring member having a thermal expansion coefficient less than that of the outer tubular member so that the constricted passage formed between the seal ring and the outer tubular member narrows during cooling. This seal assembly is adapted for use in an expansion joint employed in an oil or gas subterranean well.