Patents by Inventor Andrew John Stevens

Andrew John Stevens 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).

  • Apparatus for determining the concentration of a conductive fluid present in a fluid filled borehole
    Patent number: 8849572
    Abstract: An apparatus for determining the concentration of a conductive fluid present in a fluid filled bore hole is described. Such apparatus are known as water hold-up meters and are frequently used in oil, gas and water filled bore holes. In bore hole applications, data bandwidth between a down hole device and the surface can be limited, while determining water hold-up based on down hole measurements can be data intensive. A technique is proposed for calculating the water hold up that requires less data to be transmitted between the down hole device and the surface.
    Type: Grant
    Filed: June 6, 2008
    Date of Patent: September 30, 2014
    Assignee: Sondex Wireline Limited
    Inventors: Guy Harvey Mason, James Andrew Gulliver, Derek George Hayes, Paul Franklin Steel, Kenneth Tomkins, Andrew John Stevens
  • APPARATUS FOR DETERMINING THE CONCENTRATION OF A CONDUCTIVE FLUID PRESENT IN A FLUID FILLED BOREHOLE
    Publication number: 20100299068
    Abstract: An apparatus for determining the concentration of a conductive fluid present in a fluid filled bore hole is described. Such apparatus are known as water hold-up meters and are frequently used in oil, gas and water filled bore holes. In bore hole applications, data bandwidth between a down hole device and the surface can be limited, while determining water hold-up based on down hole measurements can be data intensive. A technique is proposed for calculating the water hold up that requires less data to be transmitted between the down hole device and the surface.
    Type: Application
    Filed: June 6, 2008
    Publication date: November 25, 2010
    Inventors: Guy Harvey Mason, James Andrew Gulliver, Derek George Hayes, Paul Franklin Steel, Kenneth Tomkins, Andrew John Stevens
  • Head tracking system
    Patent number: 6061916
    Abstract: A head tracking system 10 comprises a radiation emitter 18 and a radiation sensor 16 connected to a tracking processor 12. The emitter 18 has an output 46 producing radiation with spectral peak in the range 1000 nm to 1100 nm from a conventional LED 40 with a spectral peak in the range 500 nm to 900 nm in combination with a photoluminescent material 42.
    Type: Grant
    Filed: May 15, 1998
    Date of Patent: May 16, 2000
    Assignee: Barr & Stroud Limited
    Inventors: Andrew John Stevens, Robert Stevens, Wayne Mark Cranton