Abstract: A wellhead assembly has a metal seal that accommodates misalignment between casing and the bore of the wellhead housing. The metal seal assembly includes a metal seal ring and a wedge ring. The seal ring has a cylindrical inner wall and a conical outer wall. The centerlines of the inner and outer walls are offset with respect to each other, making the ring eccentric. Similarly, the wedge ring has a conical inner wall and an outer wall. Its inner and outer walls are offset with respect to each other. The rings can be rotated relative to each other and to the casing to coincide the axis of the outer wall of the wedge ring with the axis of the wellhead housing bore. The inner wall of the seal ring has protruding bands which deform as a result of the softness of the metal to enhance sealing.

Abstract: A lock pin for locking a pipe hanger assembly in a wellhead is hydraulically actuated. The lock pin extends through a radial passage provided in the wellhead. The lock pin moves linearly to an inner position to engage the hanger assembly. A hydraulic piston is coupled to the exterior of the wellhead for providing an inward force to the lock pin. A retainer is mounted to the wellhead by threads. While the lock pin is held in the inner position under hydraulic pressure, the retainer is rotated inward against a shoulder provided on the lock pin to hold the lock pin in the inner engaged position. The hydraulic pressure can then be removed.

Abstract: A cylindrical seal ring 20 has an inwardly extending rib 60, and upwardly 66 and downwardly 82 extending cantilever arms, each carrying outwardly facing seal surfaces 68, 84. The cantilever arms preload the seals and support the seals while providing flexibility between the seal areas and the rib 60. Temperature transients are readily accommodated.

Abstract: A production tubing for an oil well is supported by two solid structures at the wellhead. A downhole valve is controlled through pressure of a hydraulic fluid provided by a ground-level source connected to the downhole valve through a penetrating conduit formed in three segments. The first segment is formed by drilling a passage through the upper structure which communicates with a passage provided in a sleeve clamped between the two structures. The third segment is provided by drilling a passage through the lower structure which communicates with the passage provided in the sleeve.

Abstract: A normally non-rising stem valve having a valve stem (30) journaled between bearings (38, 40) is equipped with an energized drive spring (56) for positively engaging backseat seal surfaces (64, 66) upon melting of a fusible ring (52). The spring (56) is compressed axially against the retainer (46) by the cooperative action of the compression nut (58) and the tubular spacer (50), thereby normally avoiding undesirable axial thrust on the bearings (38, 40).

Abstract: The existance of fire at or near an oil field wellhead is sensed by a eutectic body which holds a valve system in a cocked position. When the eutectic is melted, the valves are positioned to terminate communication of a hydraulic fluid pressure source with a downhole safety valve and open a bleed conduit connected with the conduit to the downhole valve. A second eutectic body will melt at a different temperature than the first, providing a second position for the valve system which closes the conduit to the downhole valve and atmosphere to give positive isolation from the oil well fluid.

Abstract: A valve having a normally non-rising stem (30a,b) journaled between bearings (38a,b 40a,b) is equipped with an energized drive spring (56a,b) for positively engaging backseat seal surfaces (64a,b, 66a,b) upon melting of a fusible ring (52a,b). The spring (56a,b) is compressed axially against the retainer (46a,b) by the cooperative action of the compression nut (58a,b) and the tubular spacer (49b, 50a,b), thereby normally avoiding undesirable axial thrust on the bearings (38a,b, 40a,b).

Abstract: A multiple tubing hanger tie back arrangement is disclosed in a preferred embodiment associated with a shear ram tubing head system (10). The arrangement includes a lower tubing hanger (44) sealingly secured within a lower tubing head (28) for supporting a tubing string (22). The lower hanger includes a control shoulder (60) at its upper end and a tapered interior surface (62). An upper tubing hanger (70) spaced above the lower hanger is also sealingly secured within an upper tubing head (24). A tie back subassembly (90) connects the upper and lower hangers, and preferably includes a tubing member (94) and a spacer member (92). The spacer member includes a stab nipple (96) in interference engagement with the lower hanger interior surface (62), and a load transfer surface (98) abuting the control shoulder (60). The tubing member (94) is located in the bore of the shear ram (26) so that severance of the tubing member (94) does not disturb the production tubing string (22) supported by the lower hanger (44).

Abstract: A mudline casing hanger assembly wherein the collet (10) is retained on the hanger body (12) during running by tensile coupons (26). The lower portion (32) of the coupon is retained in slot (24) with collet slots (22) and hanger flowby slots (48) being aligned.

Abstract: A fire resistant connection (16) having heat transfer means (46) cooperatively associated therewith and that embodies a U-like sealing means (44). The fire resistant connection (16) with heat transfer means (46) is operative for purposes of effectuating the establishment of a fire resistant seal between mating surfaces (22, 18). The heat transfer means (46) includes a first heat transfer element (58), and a second heat transfer element (60). The subject fire resistant connection (16) includes the aforementioned U-like sealing means (44) and the aforereference mating surfaces (22, 18).

Abstract: A hanger collet (10) for a mudline casing suspension system in the form of a hollow cylinder. Vertical slots (32,34) create a serpentine form which is radially collapsible. Flow space behind the legs (30) permits a flowpath for running and cementing.

Abstract: There is provided a choke having an adjustable stop for absolutely limiting its degree of openness and a pressurized fluid-operated piston connected to the valve stem which normally is acted-on by differential pressure to maintain the valve open to the full extent permitted by engagement of the stem with the stop. A mechanical assistance device is provided for tending to close the valve and this device may be provided with a visual indicator from which, by inspection, one may tell the degree of openness of the valve. Remotely operable and on-site mechanical devices are shown provided for adjusting the absolute stop.

Abstract: A length-adjustable device is provided for use in applying setting force to a set of pipe slips, e.g. in a petroleum well. Then, the length of the device is adjusted and the device is installed on a seat in the head as a mechanical bridge between the set slips and an axially presented surface on an overlying part of the wellhead. Due to this interposition, the slips are prevented from losing gripping force as the suspended pipe expands and contracts.

Abstract: In order to provide a metal-to-metal annular seal for use in a high pressure environment typical of a wellhead assembly that is provided on a high pressure, high temperature gas well, especially circumferentially between the outside surface of a tubular part and the inside surface of a relatively massive part, where these parts are to have a fixed longitudinal position relative to one another in use: the available strength for developing the seal are determined; like tapering surfaces are provided on the two parts such as would provide an allowable interference fit when the two parts are brought to the fixed longitudinal position; portions of the outside surface of the tubular part are machined-away to leave tapered land areas, e.g. in two axially closely spaced bands, so that when the two parts are forced to assume the fixed longitudinal position, the seal bands provide an elastic seal that avoids total plastic deformation yet provide the required unit loading.

Abstract: For sealing between an inner part and an outer part which are generally concentrically related so as to have an annulus between them, an elastomeric sealing annulus is axially sandwiched between two beveled anti-extrusion rings, each of which has a deflectable lip. There is a first running clearance radially between this assembly and the bore of the outer part, and a second running clearance between this assembly and the outer peripheral surface of the inner part. When the two parts and the sealing assembly all reach their intended relative positions the seal is established by axially compressing the assembly sufficiently to significantly de-bevel both of the anti-extrusion rings, deflect their lips into contact with one of the parts while urging their opposite edges into contact with the other of the parts. As the elastomeric sealing annulus is axially compressed it expands radially inwards and outwards into resilient sealing engagement with the two parts.

Abstract: For sealing between two metal parts, e.g. a bonnet and a pipe string when one is coaxially received in a recess of the other, the sealing annulus includes a body of elastomeric material in communication with a reservoir of such material. This reservoir is provided with a structure for pressurizing the elastomeric material for receiving excess of such material from the sealing annulus and for supplying such material to the sealing annulus to prevent a deficiency.

Abstract: The control line exiting coupling provides radial penetration of a control line through a tubing hanger wall, with a back seat for sealing should internal pressure create a packing leak on the penetrator. The back seat further prevents withdrawal of the device through the packing and provides for withdrawing the control line tubing so the hanger may be removed from the wellhead without shearing off the control line tubing.

Abstract: A down-hole assembly is provided including particular structure for holding the assembly in place in a tubing hanger or the like. Camming wedges are associated with a cylindrical cage, the camming wedges being movable radially with respect to the cage to hold the cage in place in a tubing hanger. A tubular sleeve having camming portions thereon is concentric with the cage and effects radial movement of the camming wedges. A seal is also provided, and may include a structure that is radially movable from the cage into contact with the tubing hanger in response to axial movement of the sleeve. The sleeve may be locked in place to hold the camming wedges in holding engagement. Locking of the sleeve in place is effected by rotative movement of a locking nut. The sleeve may be released from its locked position either by reverse rotation of the locking nut or by release of an emergency retaining nut.