Patents by Inventor David W. McCulloch

David W. McCulloch has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9581009
    Abstract: The invention pertains to methods and apparatus for monitoring loads on an arched tubing guide of a coiled tubing injector caused by tension on coiled tubing. The load is sensed by a load sensor, for example, a load cell placed in a strut that supports the arched tubing guide, or in a load pin or load cell placed within the structure arched tubing guide or the connection of the arched tubing guide to a frame for the coiled tubing injector, at a location where the load is representative of the load placed on an arched tubing guide by tension in the coiled tubing. The load sensor generates a feedback signal. The load is monitored, either by an operator or a controller, and torque applied to a reel around which the tubing is wound is adjusted to avoid, or in response to, excessive loads on the arched tubing guide.
    Type: Grant
    Filed: October 15, 2013
    Date of Patent: February 28, 2017
    Assignee: National Oilwell Varco, L.P.
    Inventors: Timothy S. Steffenhagen, William Benjamin White, David W. McCulloch
  • Patent number: 9458682
    Abstract: A coiled tubing injector comprises a drive system for independently driving a plurality of chains independently but otherwise retarding relative motion between the driven chains when a chain begins to slip uncontrollably.
    Type: Grant
    Filed: September 11, 2015
    Date of Patent: October 4, 2016
    Assignee: National Oilwell Varco, L.P.
    Inventors: David W. McCulloch, Timothy S. Steffenhagen, William B. White, William G. Stewart
  • Patent number: 9353593
    Abstract: A handler holds a blowout preventer (BOP) assembly (partially or fully assembled) for transport and then erects it from a transport position to a vertical position for deployment. In the transport position the BOP assembly generally rests in a horizontal position. During deployment of the BOP assembly by the handler, the handler is capable of moving the BOP assembly to a vertical position, elevating it, and moving it outward, away from the base of the handler and toward a wellhead, so that the BOP assembly may be connected to a coiled tubing injector, work may be performed underneath the BOP assembly before connection to a well head, and the BOP assembly may be placed on top of a well head for connection to the well head.
    Type: Grant
    Filed: March 13, 2015
    Date of Patent: May 31, 2016
    Assignee: National Oilwell Varco, LP
    Inventors: Mike Xiaolei Lu, David W. McCulloch
  • Patent number: 9316067
    Abstract: A coiled tubing handler lifts and extends outwardly over wellhead a support platform on which a coiled tubing injector is mounted. The handler collapses into a compact arrangement that allows it and the coiled tubing injector to be transported to a well site on a vehicle or trailer, and then used at the well site to raise, position and support the coiled tubing injector connected to a blow out preventer and riser assembly for connection to a well head. The support platform may be tilted backward and forward, shifted from side-to-side, and raised and lowered on the platform.
    Type: Grant
    Filed: April 28, 2015
    Date of Patent: April 19, 2016
    Assignee: National Oilwell Varco, LP
    Inventors: Mike Xiaolei Lu, David W. McCulloch
  • Publication number: 20160002987
    Abstract: A coiled tubing injector comprises a drive system for independently driving a plurality of chains independently but otherwise retarding relative motion between the driven chains when a chain begins to slip uncontrollably.
    Type: Application
    Filed: September 11, 2015
    Publication date: January 7, 2016
    Inventors: David W. MCCULLOCH, Timothy S. STEFFENHAGEN, William B. WHITE, William G. STEWART
  • Patent number: 9151122
    Abstract: A coiled tubing injector comprises a drive system for independently driving a plurality of chains independently but otherwise retarding relative motion between the driven chains when a chain begins to slip uncontrollably.
    Type: Grant
    Filed: August 29, 2013
    Date of Patent: October 6, 2015
    Assignee: National Oilwell Varco, L.P.
    Inventors: David W. McCulloch, Timothy S. Steffenhagen, William B. White, William G. Stewart
  • Publication number: 20150101799
    Abstract: The invention pertains to methods and apparatus for monitoring loads on an arched tubing guide of a coiled tubing injector caused by tension on coiled tubing. The load is sensed by a load sensor, for example, a load cell placed in a strut that supports the arched tubing guide, or in a load pin or load cell placed within the structure arched tubing guide or the connection of the arched tubing guide to a frame for the coiled tubing injector, at a location where the load is representative of the load placed on an arched tubing guide by tension in the coiled tubing. The load sensor generates a feedback signal. The load is monitored, either by an operator or a controller, and torque applied to a reel around which the tubing is wound is adjusted to avoid, or in response to, excessive loads on the arched tubing guide.
    Type: Application
    Filed: October 15, 2013
    Publication date: April 16, 2015
    Inventors: Timothy S. Steffenhagen, William Benjamin White, David W. McCulloch
  • Patent number: 8727018
    Abstract: A charging unit, system and method are provided. The system includes an activation unit and a charging unit. The activation unit includes a pump unit, a pressure circuit with an unloader valve to selectively permit fluid to pass from the pump unit to the wellsite component, and an accumulator bank operatively connectable to the pressure circuit to store the fluid under pressure for passage to the wellsite component whereby the wellsite component is selectively activated. The charging unit includes a charging circuit operatively connectable to the pressure circuit to selectively receive the fluid from the pump unit, a charging accumulator operatively connectable to the charging circuit to store the fluid under pressure, and a pressure reducing valve operatively connectable to the charging circuit to selectively pass the fluid from the charging accumulator to the accumulator bank whereby an activation pressure of the fluid provided to the wellsite component is maintained.
    Type: Grant
    Filed: July 19, 2013
    Date of Patent: May 20, 2014
    Assignee: National Oilwell Varco, L.P.
    Inventor: David W. McCulloch
  • Patent number: 8701754
    Abstract: A coiled tubing injector, rollers on the backside of grippers on a gripper chain pass over at least one shallow groove or depression formed in, or gap between segments of, a planar roller contact surface of a skate, thereby momentarily removing or reducing the force being applied by the skate to the grippers as the grippers pass through at least one predetermined location within a gripping zone of the coiled tubing injector. The reduction or removal of the force on the grippers allows the grippers to reset their positions on the tubing at one or more predetermined locations in order to accommodate changes in the strain caused by changes in stress as the tubing moves through the injector.
    Type: Grant
    Filed: February 22, 2013
    Date of Patent: April 22, 2014
    Assignee: National Oilwell Varco, L.P.
    Inventor: David W. McCulloch
  • Publication number: 20140000865
    Abstract: A coiled tubing injector comprises a drive system for independently driving a plurality of chains independently but otherwise retarding relative motion between the driven chains when a chain begins to slip uncontrollably.
    Type: Application
    Filed: August 29, 2013
    Publication date: January 2, 2014
    Applicant: National Oilwell Varco, L.P.
    Inventors: David W. McCulloch, Timothy S. Steffenhagen, William B. White, William G. Stewart
  • Publication number: 20130333900
    Abstract: A coiled tubing injector, rollers on the backside of grippers on a gripper chain pass over at least one shallow groove or depression formed in, or gap between segments of, a planar roller contact surface of a skate, thereby momentarily removing or reducing the force being applied by the skate to the grippers as the grippers pass through at least one predetermined location within a gripping zone of the coiled tubing injector. The reduction or removal of the force on the grippers allows the grippers to reset their positions on the tubing at one or more predetermined locations in order to accommodate changes in the strain caused by changes in stress as the tubing moves through the injector.
    Type: Application
    Filed: February 22, 2013
    Publication date: December 19, 2013
    Applicant: National Oilwell Varco, L.P.
    Inventor: David W. McCulloch
  • Patent number: 8544536
    Abstract: A coiled tubing injector comprises a drive system for independently driving a plurality of chains independently but otherwise retarding relative motion between the driven chains when a chain begins to slip uncontrollably.
    Type: Grant
    Filed: September 24, 2010
    Date of Patent: October 1, 2013
    Assignee: National Oilwell Varco, L.P.
    Inventors: David W. McCulloch, Timothy S. Steffenhagen, William B. White, William G. Stewart
  • Publication number: 20120073833
    Abstract: A coiled tubing injector comprises a drive system for independently driving a plurality of chains independently but otherwise retarding relative motion between the driven chains when a chain begins to slip uncontrollably.
    Type: Application
    Filed: September 24, 2010
    Publication date: March 29, 2012
    Inventors: David W. McCulloch, Timothy S. Steffenhagen, William B. White, William G. Stewart
  • Patent number: 7077209
    Abstract: A mast for lifting and suspending over a wellhead a coiled tubing injector and blow out preventer is pivotally mounted on a rear portion of a truck. The mast has two side-by-side telescoping legs that extend and retract synchronously. When in a retracted position, the blow out preventer and coiled tubing injector are attached to the mast, between the legs, and legs of the mast extended to lift the equipment.
    Type: Grant
    Filed: October 25, 2002
    Date of Patent: July 18, 2006
    Assignee: Varco/IP, Inc.
    Inventors: David W. McCulloch, Mike Xiaolei Lu
  • Publication number: 20030201099
    Abstract: A flow-limiting device is placed in a hydraulic fluid circuit between a hydraulic pump of, for example, a power pack, and a motor of a coiled tubing injector. The flow-limiting device allows hydraulic fluid to flow through the circuit, but limits the rate of flow in order to avoid thermal damage to the motor.
    Type: Application
    Filed: April 25, 2002
    Publication date: October 30, 2003
    Applicant: Varco I/P, Inc.
    Inventors: Timothy S. Steffenhagen, David W. McCulloch, John E. Goode
  • Publication number: 20030079883
    Abstract: A mast for lifting and suspending over a wellhead a coiled tubing injector and blow out preventer is pivotally mounted on a rear portion of a truck. The mast has two side-by-side telescoping legs that extend and retract synchronously. When in a retracted position, the blow out preventer and coiled tubing injector are attached to the mast, between the legs, and legs of the mast extended to lift the equipment.
    Type: Application
    Filed: October 25, 2002
    Publication date: May 1, 2003
    Inventors: David W. McCulloch, Mike Xiaolei Lu