Patents Assigned to Varco Shaffer, Inc.
  • Patent number: 7380589
    Abstract: A pressure compensated tubing injector for injecting coiled tubing into a subsea wellhead or flowline. A traction device including grippers carried on respective opposing chain loops provides gripping engagement with the coiled tubing to longitudinally move the coiled tubing. A plurality of sealed outboard bearing assemblies guide movement of the chain loops. A drive unit powers the chain loops and includes a sealed gear case. One or more pressure compensators are placed in communication with the sealed gear case and one or more of the bearing assemblies, to compensate for subsea pressure and prevent intrusion of seawater. The bearing assemblies may include self-contained pressure compensators.
    Type: Grant
    Filed: December 9, 2003
    Date of Patent: June 3, 2008
    Assignee: Varco Shaffer, Inc.
    Inventors: David Wayne Martin, Ronald W. Yater
  • Patent number: 6857634
    Abstract: A blowout preventer assembly 10 includes opposed rams 12, 14, each including a rubber or elastomer sealing assembly 16, 18, with a plurality of inserts 20 forming an array 22 of metal inserts within each sealing assembly. Each insert has an upper body 24, a lower body 26, and a rib 50. Each upper and lower body includes a trailing face 36, a radially outward opposite face 38 and a leading face 40. An antiextrusion ledge 46 minimizes the extrusion gap between the OD of a tubular in the BOP and the leading face of the metal inserts in the array.
    Type: Grant
    Filed: February 20, 2003
    Date of Patent: February 22, 2005
    Assignee: Varco Shaffer, Inc.
    Inventor: Raul Araujo
  • Patent number: 6719042
    Abstract: The shear ram assembly 10 for shearing an oil well tubular T includes a first ram 16 axially moveable along the first axis 66 for moving an upper blade 17, and an opposing second ram 18 axially moveable along the second ram axis 68 for moving a lower blade 19. An upper planar surface 40 of the lower blade passes closely adjacent a lower planar surface 42 of the upper blade as the blades move towards each other to shear the tubular. The sealing system 24 is positioned within a recess 26 in the upper surface of the lower blade, and includes an elastomeric seal 28 for sealing engagement with the lower planar surface of the upper blade and a rigid actuator 30 moveable relative to the lower blade to energize the elastomeric seal.
    Type: Grant
    Filed: July 8, 2002
    Date of Patent: April 13, 2004
    Assignee: Varco Shaffer, Inc.
    Inventors: Christopher D. Johnson, Tri Canh Le, George W. Tisdale, Esteban Palomo, Jr.
  • Patent number: 6374925
    Abstract: Methods and systems are provided for drilling a well bore 60 through a subterranean formation using a drilling rig 25 and a drill string 50, whereby the bottom hole pressure while circulating drilling fluid (“ECD”) may be substantially maintained when circulation is interrupted or altered, such as when adding a joint of drill pipe to or removing a joint of drill pipe from the drill string. The method includes controllably applying and maintaining a desired variable annulus fluid pressure in the well bore, and thereafter controllably releasing the pressure from the well bore 60. In addition, methods and systems are provided for rotating the drill string while trapping, maintaining and/or releasing the well bore pressure. A substantially constant ECD pressure may be maintained on a formation, thereby facilitating the use of a lower density drilling fluid than may otherwise be required to maintain well control.
    Type: Grant
    Filed: September 22, 2000
    Date of Patent: April 23, 2002
    Assignee: Varco Shaffer, Inc.
    Inventors: Hubert L. Elkins, Mark A. Merit
  • Patent number: 6244560
    Abstract: A ram actuating mechanism 20 for a blowout preventer 10, the ram actuating mechanism 20 including a hydraulic booster for enhancing the ram closing force. The ram actuating mechanism 20 may be compatible for use with primary pistons 25 which include internal moving components, such as self locking pistons. The ram actuating mechanism 20 providing a hydraulic booster without increasing the diameter of the booster pistons above the diameter of the primary piston, such that BOP stack height need not be increased to accommodate a relatively large diameter hydraulic booster. The ram actuating mechanism 20 may utilize the same piston housing 60 as used by the primary piston, and the booster pistons 26, 28 may act mechanically in series upon the primary piston 25 to increase axial ram closing force. The ram actuating mechanism 20 may be capable of retro-fitting existing ram actuating mechanisms.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: June 12, 2001
    Assignee: Varco Shaffer, Inc.
    Inventor: Chris Dale Johnson
  • Patent number: 6192680
    Abstract: A subsea hydraulic control system 10 supplies hydraulic fluid to operate subsea equipment SE, which in exemplary application may be a blowout preventer having an opening port and a closing port. A hydraulic control system includes a fluid storage vessel 12 for storing a selected quantity of hydraulic fluid, and a separation member 16 separating subsea water from hydraulic fluid while pressurizing the hydraulic fluid in response to the hydrostatic head of the water. A fluid supply line 42 interconnects the fluid storage vessel and the subsea equipment, and a fluid exhaust line 44 interconnects the subsea equipment with a subsea hydraulic fluid reservoir vessel 14. A vent line 38 extends from the fluid reservoir vessel to the surface. A subsea pump periodically exhausts fluid from the fluid storage vessel to the water. The method of the invention provides reliable actuation of subsea equipment, and is particularly well suited for operating subsea equipment in deep water at depths in excess of 6,000 feet.
    Type: Grant
    Filed: July 15, 1999
    Date of Patent: February 27, 2001
    Assignee: Varco Shaffer, Inc.
    Inventors: James D. Brugman, Hubert L. Elkins, Mark A. Merit
  • Patent number: 5975484
    Abstract: A blowout preventer (10) is provided for use in a hydrocarbon recovery operation to prevent a well blowout. The BOP body (20) has a central passageway (22),therein for receiving an oilfield tubular T. First and second radially opposing doors (16) and (18) are provided for sealing engagement with the corresponding side face (15) on the BOP body. First and second ram assemblies (12, 14) are each supported on a respective door and may be pressure energized for driving first aid second ram blocks (24) into engagement with the oilfield tubular. A door connector (60, 90, 110, 140, 160 and 180) is provided for securing each door to the BOP body. Each door connector includes an upper connector bar and a lower connector bar (62, 64, 92, 94, 112, 114, 142, 144, 146, 148, 160 and 180) each having a bar axis generally perpendicular to the BOP body central axis.
    Type: Grant
    Filed: June 5, 1998
    Date of Patent: November 2, 1999
    Assignee: Varco Shaffer, Inc.
    Inventors: James D. Brugman, Bryce A. Levett
  • Patent number: 5897094
    Abstract: A blowout preventer 10 is provided for use in a hydrocarbon recovery operation to prevent a well blowout. The BOP body 20 has a central passageway 22 therein for receiving an oilfield tubular T. First and second radially opposing doors 16 and 18 are provided for sealing engagement with the corresponding side face 15 on the BOP body. First and second ram assemblies 12, 14 are each supported on a respective door and may be pressure energized for driving first and second ram blocks 24 into engagement with the oilfield tubular. A door connector 60, 90, 110, 140, 160 and 180 is provided for securing each door to the BOP body. Each door connector includes an upper connector bar and a lower connector bar 62, 64, 92, 94, 112, 114, 142, 144, 146, 148, 160 and 180 each having a bar axis generally perpendicular to the BOP body central axis.
    Type: Grant
    Filed: December 27, 1996
    Date of Patent: April 27, 1999
    Assignee: Varco Shaffer, Inc.
    Inventors: James D. Brugman, Bryce A. Levett
  • Patent number: 5778918
    Abstract: A two-position pilot-operated SPM valve includes an improved cage for controlling fluid flow to a ram of a subsea blowout preventer. SPM valve 10 includes a piston 48 axially movable with respect to a valve body 12, a spool 38 for moving within the valve body between an open position and a closed position, and a piston rod 34 structurally interconnecting the spool and the piston. A cage 40 within the valve body receives the spool 38, and includes an axially intermediate body 84 formed from a selected plastic material, an upper body 86 removably secured to the intermediate body and having one or more radial throughports 106 therein, and a lower body 88 removably secured to the intermediate body. An external seal 92 is provided for sealing between the intermediate body and the valve body, an internal seal 96 provides dynamic sealing engagement between the intermediate body and the exterior cylindrical surface 72 of the spool.
    Type: Grant
    Filed: October 18, 1996
    Date of Patent: July 14, 1998
    Assignee: Varco Shaffer, Inc.
    Inventor: Mark W. McLelland
  • Patent number: 5735502
    Abstract: A hydraulically controlled ram assembly 12 for an oilwell blowout preventer 10 effects the opening and closing of a ram block 30 interconnected with a piston 34. The piston 34 is movable within the ram housing 22 in response to a hydraulic pressure to seal the ram block 30 with an oilfield tubular. The hollow ram shaft 36 having a central bore is sealed with a door 20 pivotally mounted to the BOP body 16 by one or more ram shaft seals 52. The cylindrical bore 60 in the ram shaft 36 is in fluid communication with the central passageway 18 in the BOP body. A ram shaft rod 70 secured to a ram housing end plate 40 extends radially inward into the bore 60 in the ram shaft 36, and is sealed to the ram shaft by one or more rod seals 72. Wellbore pressure within the BOP that opposes ram closing is thus reduced by the sealing area of the rod seal relative to the sealing area of the ram shaft seal.
    Type: Grant
    Filed: December 18, 1996
    Date of Patent: April 7, 1998
    Assignee: Varco Shaffer, Inc.
    Inventors: Bryce A. Levett, Mike C. Nicholson
  • Patent number: 5662171
    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.
    Type: Grant
    Filed: October 4, 1996
    Date of Patent: September 2, 1997
    Assignee: Varco Shaffer, Inc.
    Inventors: James D. Brugman, Paul L. Tasson
  • Patent number: 5588491
    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.
    Type: Grant
    Filed: August 10, 1995
    Date of Patent: December 31, 1996
    Assignee: Varco Shaffer, Inc.
    Inventors: James D. Brugman, Paul L. Tasson
  • Patent number: 5575452
    Abstract: A hydraulically controlled ram actuating mechanism 10 for a blowout preventer controls the opening and closing of a ram block 12 interconnected with a ram 14 movable within a ram housing 26 along ram axis 16. The ram piston 24 and a locking piston 62 are each movable within the ram housing in response to fluid pressure. The locking piston includes a plurality of substantially planar tapered locking piston surfaces 72 circumferentially arranged on the exterior of the locking piston and inclined at an acute positive cam angle. A plurality of locking rods 40 are each secured to the ram housing 26 and are circumferentially spaced about the locking piston, with each locking rod including a substantially planar tapered locking rod surface 82 thereon inclined at an acute negative cam angle.
    Type: Grant
    Filed: September 1, 1995
    Date of Patent: November 19, 1996
    Assignee: Varco Shaffer, Inc.
    Inventors: Melvyn F. Whitby, Frank L. Sklenka, David L. O'Donnell
  • Patent number: 5505426
    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.
    Type: Grant
    Filed: April 5, 1995
    Date of Patent: April 9, 1996
    Assignee: Varco Shaffer, Inc.
    Inventors: Melvyn F. Whitby, David L. O'Donnell, Tri C. Le
  • Patent number: 5400857
    Abstract: A ram assembly for positioning within a through bore of a blowout preventer body includes first and second opposing ram pistons each powering a respective knife blade. Each knife blade may have a pair of angled shear edges on opposite sides of the respective ram centerline, with each pair of angled shear edges defining a generally V-shaped configuration. The pair of opposing knife edges preferably engage the oilfield tubular at four contact points spaced substantially equidistant about a circumference of the tubular, and thereby contain the tubular for the shearing operation. According to the method of the present invention, the oilfield tubular is sheared substantially by brittle shearing rather than ductile shearing.
    Type: Grant
    Filed: December 8, 1993
    Date of Patent: March 28, 1995
    Assignee: Varco Shaffer, Inc.
    Inventors: Melvyn F. Whitby, David L. O'Donnell