Patents by Inventor David J. Mathis

David J. Mathis 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).

  • Subsea tree safety control system
    Patent number: 8347967
    Abstract: An embodiment of a method for limiting the probability of failure on demand of a subsea test tree (“SSTT”) includes the steps of providing a safety shut-in system for actuating a safety valve of the SSTT, the safety shut-in system including a surface control station positioned above a water surface connected via an umbilical to a subsea control system positioned below the water surface to actuate the safety valve; and diagnostically testing the safety shut-in system without actuating the safety valve.
    Type: Grant
    Filed: April 17, 2009
    Date of Patent: January 8, 2013
    Assignee: Sclumberger Technology Corporation
    Inventor: David J. Mathis
  • SUBSEA TREE SAFETY CONTROL SYSTEM
    Publication number: 20090260829
    Abstract: An embodiment of a method for limiting the probability of failure on demand of a subsea test tree (“SSTT”) includes the steps of providing a safety shut-in system for actuating a safety valve of the SSTT, the safety shut-in system including a surface control station positioned above a water surface connected via an umbilical to a subsea control system positioned below the water surface to actuate the safety valve; and diagnostically testing the safety shut-in system without actuating the safety valve.
    Type: Application
    Filed: April 17, 2009
    Publication date: October 22, 2009
    Applicant: Schlumberger Technology Corporation
    Inventor: David J. Mathis
  • Subsea communications system
    Patent number: 7261162
    Abstract: A subsea communications module includes an interface to communicate with a surface facility over a communications link using a packet-based protocol. The communications link can be implemented with a fiber optic line, wire-based line, and/or other types of communications lines.
    Type: Grant
    Filed: August 15, 2003
    Date of Patent: August 28, 2007
    Assignee: Schlumberger Technology Corporation
    Inventors: Gregor E. Deans, Roderick MacKenzie, John A. Kerr, David J. Mathis, Eric Smedstad
  • Subsea communications system
    Publication number: 20040262008
    Abstract: A subsea communications module includes an interface to communicate with a surface facility over a communications link using a packet-based protocol. The communications link can be implemented with a fiber optic line, wire-based line, and/or other types of communications lines.
    Type: Application
    Filed: August 15, 2003
    Publication date: December 30, 2004
    Inventors: Gregor E. Deans, Roderick Mackenzie, John A. Kerr, David J. Mathis