Abstract: A hydraulically controlled blowout preventer 10 and method are disclosed for simultaneously moving two sealing assemblies 24, 27 to seal around an oilfield tubular 15 within the bore 14 of BOP 10. A single manual operator 20 may be rotated to simultaneously move master piston 26 and hydraulically interconnected slave piston 79 inwardly toward bore 14 or outwardly away from bore 14, respectively. BOP 10 is field convertible to purely hydraulic operation by disconnecting the threaded shaft 52 from master piston 26. Hydraulic lines 36 and 40 interconnect between cylinders 30 and 82 to result in simultaneous operation of seal assemblies 24, 27.

Abstract: A blowout preventer comprises apparatus for allowing the pressure above and below its rams to equalize before the rams are opened. At least one of the rams has a bypass passageway therethrough disposed so as to allow communication between well zones above and below the rams, respectively. The bypass passageway also has a straight-sided tubular sealing section intermediate its ends. A sealing piston carrying a circumferential seal sized to engage the sealing section of the bypass passageway is reciprocable in that passageway to move the circumferential seal into and out of engagement with the sealing section and thereby respectively prevent or permit fluid flow through the bypass passageway. Where the actuator shaft for the ram is connected to the ram by a lost motion type connection, the sealing piston may be carried on the shaft.

Abstract: Apparatus and methods for sealing a parallel expanding gate valve are provided using upper and lower wedges separate from and located between the gate segments. The gate segments are symmetrical with respect to each other and have inner upper and lower tapered surfaces. Inclined surfaces on the upper wedge press the inner upper tapered surfaces of the gate segments. The inner lower tapered surfaces of the gate segments also press against inclined wedging surfaces on the lower wedge. This wedging action forces the gate segments outward with respect to each other and with substantial force against sealing assemblies to close and seal the gate valve.

Abstract: An improved packing assembly is provided for forming a metal-to-metal sealing engagement between an outer cylindrical surface and an inner cylindrical surface within downhole or surface hydrocarbon recovery equipment having an axially extending flow path therein. The packing assembly includes an outer seal ring and a inner seal ring with upper and lower tapered surfaces, an upper energizing ring and a lower energizing ring each having tapered surfaces for sliding engagement with a tapered surface of the seal rings, and an interconnection member for limiting axial movement of the energizing rings.

Abstract: A blowout preventer is provided with an improved sealing assembly for sealing engagement with a pipe extending through the blowout preventer into a well bore. The sealing assembly includes an elastomeric seal and a plurality of circumferentially spaced metal inserts within the seal for substantially minimizing or preventing extrusion of the seal under high fluid pressure. The BOP be reliably used for sealing engagement with pipes of varying diameters. Each insert has a substantially I-shaped configuration with an upper flange, a lower flange, and a rib fixedly interconnecting the flanges. A slot is provided within at least one of the flanges and forms a cavity for receiving a male interconnecting member extending circumferentially from an adjacent one of the inserts, such that the circumferentially spaced inserts are interconnected to minimize extrusion gaps between the inserts and to better enable the sealing assembly to form a positive seal with the pipe.

Abstract: A blowout preventer is provided with an improved sealing assembly for sealing engagement with a pipe extending through the blowout preventer into a well bore. The sealing assembly includes an elastomeric seal and a plurality of circumferentially spaced metal inserts within the seal for substantially minimizing or preventing extrusion of the seal under high fluid pressure. The BOP be reliably used for sealing engagement with pipes of varying diameters. Each insert has a substantially I-shaped configuration with an upper flange, a lower flange, and a rib fixedly interconnecting the flanges. A slot is provided within at least one of the flanges and forms a cavity for receiving a male interconnecting member extending circumferentially from an adjacent one of the inserts, such that the circumferentially spaced inserts are interconnected to minimize extrusion gaps between the inserts and to better enable the sealing assembly to form a positive seal with the pipe.

Abstract: A holddown screw assembly 10 which features a shaft 33, an energizer screw 39 and a detachable contact nose 20 adapted to be assembled in coaxial alignment in a radial bore in a wellhead structure. The shaft is provided with a passage 40 extending from its outer end as the holddown screw is normally used in a wellhead installation to a cross passage 41 at the other end of the shaft. Also, at its outer end, a fitting 32 is attached to facilitate connection to a hydraulic supply line 28. An annular bearing flange 35 is provided on the shaft near its outer end. A packing nut 31 and a set of packing rings 34 are sleeved about the shaft 33 with the nut disposed in abutting relation to the bearing flange 35 where it is held fixed but rotatable thereagainst by means 36. The packing nut is threaded into a threaded section of a bore 11 such as may be provided in the flange 12 of a casing spool 13. By turning the packing nut, the packing ring set may be compressed against a shoulder 37 in the bore 11.

Abstract: A holddown screw 10 which features a shank 23 and contact nose 22 of separate construction. The contact nose 22 is provided with a flat bevelled contact surface 32 of predetermined angle to the axis of the screw selected to correspond to the angle of the camming surface 17a with which it is designed to cooperate. The contact nose is carried on the shank 23 and is adapted for relative rotation thereon as the screw is rotated. The back end of the contact nose is provided with an annular surface 22a disposed radially to the longitudinal axis of the screw and adapted to engage an annular shoulder 35 of the shank 23 in flat co-planar relationship therewith. As the screw is rotated and driven inwardly to contact the wellhead component 14 to be actuated, the flat contact surface 32 of the nose of the screw will engage in sliding contact with the cooperating camming surface 17a.

Abstract: A high pressure sealing connection for sealing between coaxially aligned members (22, 10) which are connected by metal bolt means having a different coefficient of thermal expansion from the aligned members. The connection comprises a metallic sealing ring (40) having at its largest external diameter a curved arcuate peripheral surface 52 characterized by a center of curvature which is co-diametral with the center of the seal ring but may be of greater or lesser radius than the radius of the ring. At its inner periphery, upper and lower flanges (61, 62) extend inwardly and perpendicularly to the axis of the ring. The coaxially aligned members (22, 10) are provided with recesses defined by opposed internal frusto-conical sealing surfaces (41, 42) at their adjoining ends, each tapering inwardly from the end of the member to an annular shoulder (43, 44) in the bore of the aligned member. The frusto-conical surfaces (41, 42) are of equal taper in the range of 5 degrees to 20 degrees.

Abstract: A crossover seal assembly (44) for sealing the annulus between a well casing (16) and tubing head (22). The assembly includes spaced pairs of upper and lower metal seal rings (60 and 72, 108 and 120) having matching frusto-conical wedging surfaces (70 and 74, 118 and 122) which interact when an axial compressive force is applied to thereby effect a controlled radial expansion of the seal rings to sealingly engage the inner and outer cylindrical surfaces (48, 47) of the tubing head (22) and well casing (16). The axial compressive force is mechanically applied by a plurality of holddown lock screws (90) which interact through tapered conical tips (94) to energize the crossover seal assembly (44).

Abstract: An expanding gate valve (10) provided with a piston type pneumatic powered actuator (40) for opening and closing the valve wherein the actuator piston (54) is adapted to be driven by fluid pressure in one direction to operate the valve but is returned by spring means (63, 64) when the pressure is removed. The actuator includes a hydraulic choke means (71) comprising a hydraulic piston (80) and cylinder (72) wherein the hydraulic piston is fixed to the actuator stem (23) and is provided with an orifice (89) which imposes a constant velocity control on the actuator stroke by producing a throttling effect on the hydraulic fluid moving from one side of the hydraulic piston to the other. The hydraulic cylinder (72) is filled with a fluid which maintains substantially uniform viscosity in the range of minus 40.degree. Centigrade to 204.degree. Centigrade whereby the valve is adapted for consistent operation during rapid cycling conditions.

Abstract: A pressure energized mechanically preloaded packing assembly (48, 68) of a high pressure gate valve (10). The packing assemblies are positioned in an annular space about the valve stems (36, 64) for sealing between the valve stems and bonnet (38) or valve body (12). The packing assemblies include an energizer ring (78) which is positioned within the annular space having an outwardly facing precision cut frusto-conical end surface (82) relative to the flow passage (16, 18) of the valve. A plurality of Belleville springs or spring washers (98) with a generally frusto-conical shape are positioned adjacent and in concave relation to the outer end (82) of the energizer ring. The cone angle of the spring washers are smaller than the cone angle of the energizer ring. The packing assembly further includes at least one packing ring set positioned outside the spring washers (106, 108) which includes a stack of plastic packing elements (110) which are sandwiched between a pair of retainer rings (112, 114).

Abstract: A pressure energizable packing assembly (47) for sealing the stem and valve body of a high pressure valve. The assembly comprises one or more sets (60, 61) of packing rings (62) which are adapted to be compressed between a pair of retainer rings (64, 65) and radially expanded into sealing engagement with the valve stem (45) and valve body (11). The retainer rings are actuated by Belleville springs (70) in a preloaded condition of the assembly and additionally by fluid pressure in the valve body after installation. The packing assembly includes an adapter ring plug (71) for accommodating its connection in the valve body. The packing assembly is assembled as a cartridge and held together by screws (77) which extend through the adapter ring (71), the outer retainer ring (64), the packing ring sets (60, 61) and their separating spacer ring (63), and which are anchored in the inner retainer ring (65).

Abstract: A pressure energizable sealing connection for establishing a bore seal between first and second coaxially aligned and connected members (22, 10) having opposed internal recesses forming seat pockets at their adjoining ends. The invention comprises a sealing ring (40) having annular end surfaces (56, 54) and an internal diameter which corresponds to the bores of the coaxially aligned members (22, 10), the connection of which is to be sealed. The ring (40) is provided with a pair of circumferential projections (67, 68) separated by a groove (69) therebetween and each having an external surface of arcuate configuration. At their adjoining ends (25, 26) the opposed seat pockets of the adjoining members (22, 10) provide annular cylindrical walls (41, 42) for sealing engagement with the annular projections (67, 68) of the sealing ring (40).