Abstract: The rotatable blowout preventer 10 includes a stationary outer housing 12 and a rotatable inner housing 38 having a curved surface 42 thereon defining a portion of a sphere. An annular packer assembly 46 includes spherical packer elements for sliding engagement with the curved surface of the inner housing such that a packer assembly may seal against various sized tubulars. A lower rotary seal 98 between a piston 56 and the outer housing 12 is exposed to the differential between pressurized hydraulic fluid and the well pressure within a lower end of the bore 32 within the outer housing. A flow restriction member 114 between the rotatable inner housing and the outer housing reduces fluid pressure downstream from the flow restriction to less than 40% of the upstream pressure. The upper rotary seal 120 is open to atmospheric pressure and is subjected to this reduced pressure.

Abstract: The rotatable blowout preventer 10 comprises a stationary outer housing 12 and a rotatable inner housing 38 having a curved surface 42 thereon defining a portion of a sphere. An annular packer assembly 46 includes spherical packer elements for sliding engagement with the curved surface of the inner housing such that a packer assembly may seal against various sized tubulars. A lower rotary seal 98 between a piston 56 and the outer housing 12 is exposed to the differential between pressurized hydraulic fluid and the well pressure within a lower end of the bore 32 within the outer housing. A flow restriction member 114 between the rotatable inner housing and the outer housing reduces fluid pressure downstream from the flow restriction to less than 40% of the upstream pressure. The upper rotary seal 120 is open to atmospheric pressure and is subjected to this reduced pressure.

Abstract: A pipe handling machine for moving well pipes arranged essentially horizontally and essentially parallel to one another on a deck, and including a carriage which may contain an operator's control cabin and is mounted by tracks for movement transversely of the pipes, with an arm projecting from the carriage and adapted to support a pipe from one of its ends as a cantilever, and with the arm being power actuable upwardly and downwardly to raise and lower a pipe and in its elevated position shift the pipe laterally with the carriage. The arm may deliver the pipe to or receive it from an inclined conveyor leading to the rig floor. Preferably, two such machines are provided for shifting pipes on two storage decks at different levels, and for delivering pipes to or from an intermediate conveyor system extending between the two decks.