Abstract: Apparatus is disclosed for use in drilling and completing a subsea well of the type in which a blowout preventer stack positioned on a floating rig is connected to the well by a drilling riser, and wherein the flow of well fluid between the tubing/casing annulus and the upper end of the wellhead is controlled by valves means within passageway in a relatively thick walled upper portion of the housing above a relatively thin walled portion thereof in which a casing hanger is installed.

Abstract: There are disclosed two embodiments of a subsea drilling, completion and/or workover apparatus which includes a spar buoy having a well therethrough, and a riser which extends through the well in the buoy for connection to the subsea wellhead during the drilling and/or completion process. A buoyancy tank is disposed about the riser within the buoy well to support the riser, and the upper end of the tank is fee to move vertically with respect to the well deck so that it will not be placed in compression despite anticipated rise and fall of the buoyancy tank.

Abstract: There are disclosed two embodiments of a connector for use in supporting a riser from cable which extend about sheaves intermediate the riser and a tensioning device located on a floating rig above a subsea wellhead to which the lower end of the riser is to be anchored. Each connector is of such construction that the cable may be advanced through an opening in a body of the connector in order that the wear point on the cable where it passes over the sheave may be changed from time to time without having to detach and reattached it from and to the riser.

Abstract: Subsea wellhead apparatus is disclosed in which a hanger is adapted to be lowered into and landed in a predetermined orientational and longitudinal position within the bore of a wellhead housing installed on a subsea well in order to suspend a tubing string within the well bore. The hanger has a passageway with one adapted to connect with a tube extending downwardly into the well bore for connection with an operator for a subsurface safety valve in the tubing string, and another end which connects with the outer side of the hanger opposite the bore of the housing. The housing has a passageway therethrough with one end in general alignment with the other end of the passageway in the hanger to form a continuation thereof when the hanger is landed in the housing. A body on the outer side of the housing has passageway means with one end in general alignment with the other end of the housing passageway and another end for connection with a control line external to the housing.

Abstract: There are disclosed a wellhead system and a method for use in drilling a subsea well from a jackup platform which includes a wellhead housing which is installed on a surface casing of a subsea well. A first riser having a connector on its lower end is lowered over the upper end of the housing as the connector to land on the housing, and a second riser is lowered through the first riser and connector over and onto the upper end of the wellhead housing to form an upward continuation of the bore of the housing. The connector has locking parts which are movable between outer unlocking position to permit the second riser to be lowered onto and raised from the wellhead housing, and inner positions for locking engagement with the upper end of the housing and lower end of the second riser. A casing hanger is lowered through the second hanger and into landed position within the housing bore for suspending an inner casing string within the surface casing.

Abstract: There are disclosed two embodiments of a connector for sealably connecting the lower ends of an upper riser member and an upper conduit on the lower ends of an upper riser pipe and upper auxiliary line joint, respectively, to the upper ends of a lower riser member and a lower conduit on the upper ends of a lower riser pipe and upper conduit thereof, respectively. At least one of the conduits includes a telescoping sealed joint which is of such construction as to permit differential movement between the riser and the auxiliary line.

Abstract: There is disclosed an assembly including a protective sleeve spaced about an intermediate pipe of a riser which is adapted to extend through an opening in the bottom of a vertical compartment of a offshore rig for use in drilling or completing a subsea well, with a ball shaped portion on the upper end of the sleeve is closely received by ball shaped surfaces of the upper portion of the riser pipe, while a ball shaped part on the lower portion of the riser pipe is so received within the lower end of the sleeve to permit them to swivel as well as to move vertically with respect to one another.

Abstract: There are disclosed two embodiments of subsea wellhead apparatus each of which includes a subsea wellhead housing installed at the ocean floor, a casing hanger connectable to the to the upper end of a casing string and supported in the bore of the housing to suspend the casing string in the well bore, and a tubing hanger connectable to the upper end of a tubing string and also supported within the housing bore above the casing hanger for suspending the tubing string within the casing string. A primary valve and a secondary backup valve are installed in series for controlling a passageway in the tubing hanger, and during the completion process, with an additional passageway in a Christmas tree which is installed on the head above the tubing hanger.

Abstract: Apparatus is disclosed for use in lowering an object such as a well pipe through a guide tube suspended from the water surface and onto an upstanding subsea conduit beneath the lower end of the guide tube.

Abstract: There is disclosed a connector for releasably connecting tubular members connected to adjacent ends of riser pipes in end-to-end relation. The tubular members have locking grooves about their adjacent ends, and a split lock ring surrounds the adjacent ends of the tubular members, when in end-to-end relation, and has upper and lower teeth thereabout for fitting tightly within the grooves to hold the ends of the tubular members in end-to-end relation. The lock ring is moved between locking and unlocking positions by means of a cam ring having tapered conical cam surfaces thereabout for slidable engagement with follower surfaces about the lock ring. A support plate extends laterally from each tubular member, and pipes, which may be choke and kill/lines, one mounted on the plates to sealably interfit with one another upon movement of the tubular members into end-to-end relation.

Abstract: There is disclosed well apparatus wherein a so-called "backout sub" connected by right-hand threads at its lower end to a lower well pipe has both left-hand threads thereabout for connection with left-hand threads on the lower end of one upper tubular member to permit it to be released and raised from the lower tubular member, in response to right hand rotation of the upper tubular member, and right-hand threads for connection with right-hand threads on the lower end of another upper tubular member for use in tying the lower tubular member and thus the lower well pipe back to the head of the well in response to right-hand rotation.

Abstract: There is disclosed a connector for releasably connecting tubular members connected to adjacent ends of riser pipes in end-to-end relation. The tubular members have locking grooves about their adjacent ends, and a split lock ring surrounds the adjacent ends of the tubular members, when in end-to-end relation, and has upper and lower teeth thereabout for fitting tightly within the grooves to hold the ends of the tubular members in end-to-end relation. The lock ring is moved between locking and unlocking positions by means of cam rings having tapered conical cam surfaces thereabout for slidable engagement with follower surfaces about the upper and lower ends of the lock ring.

Abstract: There is disclosed an apparatus for use in drilling an offshore well wherein the upper end of a riser is intermittently supported from a floating vessel to permit the lower ends of additional pipe sections to be connected thereto and then lowered through the table for connection at its lower end to an underwater wellhead. The riser is supported from the vessel in such a manner as to absorb the load of the riser as an additional section is landed on its upper end, and then carry the load of the riser as the vessel tilts or rolls without imposing undue bending loads on the riser.

Abstract: There are disclosed several embodiments of a connector for connecting tubular members in end-to-end relation wherein a ring supported by the one tubular member carries arcuate latches which are adapted to be moved by radial actuators into and out of positions in which locking shoulders thereon are tightly engaged with a complementary locking shoulder about the other tubular member to hold the members in end-to-end relation.

Abstract: Apparatus for connecting the bore through a diverter assembly with the bore through a blowout preventer stack beneath an offshore drilling rig include an upper tubular member adapted to be connected to the diverter assembly to form a lower continuation of the lower end of its bore, a lower tubular member adapted to be connected to the blowout preventer stack to form an upper continuation of the upper end of its bore, and a tubular body extending between and pivotally and sealably connected to the upper and lower tubular members to connect their bores.

Abstract: There is disclosed a wellhead connector for connecting first and second tubular wellhead members in end-to-end relation, wherein locking segments are carried by a ring about the first member for movement between an outer position, to permit the ring to be moved over an outer surface of the second member, to an inner position in which locking shoulders on the inner ends of the locking segments slidably engage a locking shoulder about the outer surface of the second member to urge the ends of the members into tight engagement. The locking segments are moved to their inner positions by means of wedges guidably movable in the ring outwardly of the locking segments and having surfaces slidable over surfaces on the outer ends of the segments as the wedges are moved toward one another, and are moved to their outer positions, as the wedges move away from one another, by means of coil springs acting between the body and locking segments.

Abstract: There is disclosed wellhead apparatus for use in suspending a pipe string within the bore of a housing of the wellhead. The apparatus includes a slip bowl landed on a seat in the bore and a slip assembly supported within the slip bowl in a retracted position which permits the bowl and slip assembly to be lowered into landed position within an annular space between the pipe string and bore of the housing by a series of elongate rods extending within the annular space and adapted, upon rotation in one direction, to force the slip assembly downwardly and inwardly into engagement with the pipe string, and thereby suspend the weight of the pipe string from the slip assembly, and upon rotation in the opposite direction, to permit them to be released from the slip assembly and removed from within the annular space.

Abstract: There is disclosed wellhead apparatus in which a pipe string is suspended within the bore of a housing and the annular space between the bore and the outer wall of the pipe string or a mandrel-type hanger from which the pipe string is suspended is closed by a seal assembly. The seal assembly is lowered into the annular space on a tool so as to close the same as seal rings carried about the outer and inner sides of the body are energized into sealing engagement with the bore of the housing and the outer wall.

Abstract: There is disclosed wellhead equipment wherein a tubing hanger suspended from a running tool lowered with the running tool into a landed position within a bore of a casing head, and a seal assembly suspended from the running tool is, upon landing of the hanger, lowered into an annular space between the tubing hanger and bore so as to seal with respect to them and thereby close the space.

Abstract: There is disclosed a unitized wellhead system wherein each of concentric well strings are suspended within a well bore by means of individual hanger mandrels installed within the bore of a single wellhead housing.