Varco Shaffer, Inc.

Baroid Technology, Inc.

Paul L Tasson

James Dennis Brugman

Tri C Le

Scott K Beall

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. Improved techniques are provided for passing hydraulic fluid through the blowout preventer for both closing and opening the sealing assembly 46.

Rotating blowout preventer and method

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. Improved techniques are provided for passing hydraulic fluid through the blowout preventer for both closing and opening the sealing assembly 46.

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.

Growing community of inventors

Missouri City, TX, United States of America

Paul L Tasson