Abstract: A metal-to-metal fluid tight seal configuration formed between two abutting tubular members for use in subterranean oil and gas wells is disclosed. A metal-to-metal fluid tight seal is utilized in a shear release expansion joint assembly mounted by means of an anchor seal assembly in a conventional downhole packer. Sealing engagement is provided by plastic deformation of an annular seal ring between two abutting tubular members which are less ductile than the seal ring. In the preferred embodiment the metal-to-metal fluid tight seal is formed between abutting box and pin tubular members and the plastic deformation of the circular ring occurs as the ring is received within a groove in one of the abutting tubular members which has a dissimilar profile in comparison to the cross-section of the circular ring. Plastic deformation occurs as the box and pin members are rotationally threaded together and a continuous fluid tight seal is maintained along surfaces of both tubular members.

Abstract: A valve apparatus for use in an intermittent gas lift subterranean well, having a reservoir with insufficient pressure for continuous delivery of produced fluids to the top surface of the well is disclosed. A valve apparatus carriable on a fluid transmission conduit has a flow passage for permitting produced fluids to flow through the transmission conduit from the reservoir. The valve is responsive to pressure to open the valve in the presence of a greater pressure exerted by the reservoir below the valve, and to close the valve in response to an even greater pressure generated by intermittent gas injection. A second flow passage selectively communicating with a radially extending port permits the flow of injected fluids from the tubing into the reservoir. A second valve, for selectively opening and closing the second flow passage, is spring biased in the closed position so that it remains closed when subjected to reservoir pressure, intermittent gas pressure, or their sum.

Abstract: An apparatus is provided for producing a well from at least one productive zone penetrated by the well bore in which casing is set below the top of the well. Tubing hanger means support at least one production tubing string extending downwardly in the well bore and communicating with a production zone. Anchor means on the tubing hanger means are actuatable into anchoring engagement with the casing. The tubing hanger means receives at least one upper production tubing string section typically carrying safety valve means thereon extending to the top of the well and sealingly engageable with the tubing hanger means before, during and after the anchoring engagement of the tubing hanger means with the casing, whereby the upper production tubing string section is respectively communicable with the downwardly extending production tubing string when the tubing hanger is set.

Abstract: An apparatus is provided which is connectable on a tubing string extendible into a subterranean well. The apparatus is selectively separatable whereby the tubing string may be parted. The apparatus comprises first means selectively retrievable from the apparatus for carrying across the apparatus a first weight load defined through the tubing string below the apparatus. Second weight load carrying means are provided for carrying across the apparatus a second weight load defined through the tubing string below the apparatus, the second weight load being less than the first weight load. The second means are activatable to separate the apparatus and the tubing string when the second weight load is exceeded.

Abstract: A control tool is provided which is insertable through a tubing string in a subterranean well for selectively transmitting fluid pressure through the tool in first and second fluid flow paths for application of the pressure to activate an auxiliary tool on the tubing string, the auxiliary tool typically having first and second piston chambers and piston means in communication therewith, the chambers receiving fluid pressure delivered through the control tool. The control tool comprises a cylindrical housing with means defining first and second selectively pluggable fluid ports thereon. One of the ports is communicable with the first piston chamber, with the other port communicable with the second piston chamber. First and second selectively pluggable fluid vent passageways are defined through the housing with one of the vent passageways being communicable to one of the piston chambers, and the other of said vent passageways being communicable to the other of the piston chambers.

Abstract: The present invention provides a latch assembly carriable on a tubing string extendible into a subterranean well, the latch assembly being selectively engageable between upper and lower sections of the tubing string. The latch assembly comprises an outer housing and an inner body, with latching means carried on one of the housing and the body for selectively securing the latch apparatus to the lower section. Latch engaging means are carried on the other of the housing and the body and the lower tubing section for selective co-engagement between the latching means, the lower tubing section, and one of the housing and the body. Piston means are on one of the housing and the body and have a piston head with first and second piston chambers between the piston head.

Abstract: An apparatus which is carriable on a tubing string extendible within a subterranean well, wherein the tubing string has an upper tubing section which is extendible from and above the apparatus to the top of the well, and a lower tubing section which is extendible from and below the apparatus. The apparatus is manipulatable to rotate the lower tubing section without rotating the upper tubing section and comprises first and second housings, one of the housings and the lower tubing section being rotatable relative to the other of the housings. Actuator means are insertable within at least one of the housings for applying rotation to one of the housings. Co-engaging means are provided on the actuator means and one of the housings for applying rotational force to one of the housings and the lower tubing section to rotate the one housing and the lower tubing section without rotating the other of the housings and the upper tubing section.