Abstract: An apparatus is provided capable of absorbing shocks due to decelerating forces caused by landing of a marine riser on a spider resting on a rotary table. The apparatus includes a hydraulic shock absorber mounted on the rotary table which supports the spider on which the riser lands, the load and shock of the riser moving pistons in cylinders to force hydraulic oil in the cylinders through an orifice into an accumulator, effecting shifting of an accumulator piston against compressed air in the accumulator, which can exhaust through a pressure relief valve. The above action decelerates the riser and spider. Upon removing the weight of the riser from the spider, the compressed air in the accumulator, supplied from the suitable source, moves the accumulator piston back to its initial position, which acts through the hydraulic oil to effect upward return of the pistons to their initial positions. The apparatus permits lateral translation of the spider and also its tilting in all directions to limited degrees.

Abstract: A system for conveying fluid from a single subsea supply conduit to provide a fluid supply for each of a plurality of subsea well control apparatus requiring fluid supplies at different pressure levels. A fluid receiver receives fluid under pressure from the single subsea supply conduit, and a regulator regulates fluid flow from the receiver to charge one or more accumulators with fluid at desired pressure levels and to control injection of the fluid through an injection line into a subsea well flowline. The fluid used with the system may be glycol, methanol, or other suitable freezing retardants.

Abstract: A buoy having a controllable buoyancy and being particularly adapted for subsea use. The buoy includes an upper buoyant chamber member mounted with a lower chamber member. The lower chamber member has a lower chamber formed in it for containing variable amounts of a fluid which is buoyant in water and for containing variable amounts of water. The lower chamber member additionally has an opening formed in its bottom to permit water to pass into and out of the lower chamber and fill the portion of the lower chamber which is not occupied by the buoyant fluid. A control assembly operably connected to the lower chamber regulates the amounts of buoyant fluid in the lower chamber so that the buoyancy of the buoy is controlled.

Abstract: A seal apparatus adapted to be set in packed-off condition in the annular region between the hanger body and the surrounding wellhead housing disposed at the upper end of a well bore, the seal apparatus then being locked in its packed-off condition by a locking ring and a locking ring actuator. A retrieving tool is employed to release the lock ring, such tool having resilient fingers engageable with the actuator to elevate it from wedging relation to the lock ring and permitting the latter to expand from its locked condition, whereupon the retrieving tool can elevate the seal apparatus, lock ring, and actuator from the region between the hanger body and wellhead housing. The retrieving tool includes a body having passages from which washing fluid can discharge to clean the region between the hanger body and wellhead housing. In one form of retrieving tool, the resilient fingers may be released from the actuator in response to fluid pressure supplied through a running string secured to the retrieving tool.

Abstract: An improved underwater connection apparatus is provided for selectively making fluid connection between a Christmas tree flowline and a flowline extending underwater from surface storage facilities, the storage flowline being pulled into a position of partial alignment with the Christmas tree flowline by a wireline device and completely axially aligned by a remotely operable hydraulic mechanism, the two flowlines being thereafter secured together for fluid transfer.

Abstract: An improved underwater connection apparatus is provided for selectively making fluid connection between a Christmas tree flowline and a flowline extending underwater from surface storage facilities, the storage flowline being pulled into a position of partial alignment with the Christmas tree flowline by a wireline device and completely axially aligned by a remotely operable hydraulic mechanism, the two flowlines being thereafter secured together for fluid transfer.

Abstract: A guidance apparatus for re-entering a sub-sea wellhead or christmas tree after the guidelines extending to the water surface have been removed. The apparatus includes a remotely actuated marker buoy secured by a reeled line to an upwardly projecting keyed buoy post at the wellhead and a second upwardly projecting keyed post is positioned near the well centerline adjacent to the buoy post and the wellhead. The apparatus also includes a re-entry funnel adapted to be run from the surface on a cable attached to either post and having an internal cam engageable by the key on the post to orient the re-entry funnel and align any tools carried thereby with respect to the wellhead, tree or other parts of the sub-sea wellhead structure.

Abstract: A control valve providing various predesignated output signals in response to changes in the pressure of a fluid input signal including a position responsive member mounted for operative connection with such fluid input signal for movement to various positions to direct the fluid input signal outwardly as a selective output signal.

Abstract: A magnetic flux leakage method and apparatus for inspecting magnetizable test objects such as pipelines are disclosed. Magnetic diodes are connected to give temperature-independent readings of flux leakage and are spaced apart according to the size of the flaws sought to be detected. Groups of diodes are overlapped to provide complete coverage of the area sought to be inspected. Certain of the largest signals received at any one time from the groups of diodes are transmitted to recording means to reduce the number of signals recorded. Diode signals are subtracted from each other to determine relative differences in detected fluxes. For inspecting pipelines, the diodes and magnets are mounted on the apparatus by mounting assemblies which pivot about three axes and the diodes and magnets are urged yieldingly toward the pipeline wall by members formed of open cell foam polyurethane.

Abstract: A retrieving tool has resilient fingers engageable with a pulling collar of the actuator ring of a wedge locked underwater wellhead packing to release the lock and the packing for retrieval from the wellhead. The retrieving tool has a body connected to a running pipe string and provided with washing ports. In one form the resilient fingers are releasable from the pulling collar in response to fluid pressure supplied through the running string.

Abstract: Emergency shutoff valve apparatus, including a gate valve assembly actuated to a closed position by fluid pressure acting on an actuator piston, such actuation causing the piston to exert a force through a liquid medium on a power piston to store energy in a spring device or other energy storing means. Relieving of the fluid pressure acting on the piston causes the energy storing means to act through the power piston and liquid medium to shift the actuator piston to a position closing the gate valve assembly. The gate valve assembly can also be shifted to a closed position by supplemental fluid pressure acting on the power piston or on an override piston.

Abstract: The traveling block of the derrick mounted on a floating barge is connected in off-center relation with a load supporting motion compensator cylinder, the sheaves being located and strung asymmetrically with respect to the center line of the motion compensator cylinder. The crown block sheaves are rotatable on axes which are skewed to reduce fleet angle of the line. Different size sheaves are strung differently and different numbers of line runs are strung differently to equalize the forces about the center of gravity of the mass of the traveling block.

Abstract: A buoyant marine riser system adapted to extend from a floating platform to a subsea wellhead wherein one or more riser sections include a series of circumferentially spaced, elongated, hollow, closed buoyant tanks containing a gaseous medium to make such riser sections substantially buoyant.

Abstract: Running apparatus is releasably connected to a packing assembly, the combination being lowered on a tubular running string until the packing assembly is disposed between a hanger body and a surrounding wellhead underlying a body of water. The apparatus is responsive to weight to effect setting of the packing in the annular space between the hanger body and wellhead. Test pressure is applied to the packing and more firmly sets it. The apparatus is rotated relative to the packing to shift a locking nut to lock the packing in place, the apparatus then being retrieved to the drilling rig at the water surface.