Patents by Inventor John W. A. Millar

John W. A. Millar 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).

  • Hydraulic impedance test method
    Patent number: 5170378
    Abstract: A method for determining the height and length of a fracture (3) in a borehole (1) involves generating pressure waves in the fluid in the wellbore using a valve (4) and measuring the response at the well-head by means of a transducer (5). A theoretical model of the wellbore-fracture system is generated and compared with the measured response to determine the height and length of the fracture.
    Type: Grant
    Filed: April 6, 1992
    Date of Patent: December 8, 1992
    Assignee: The British Petroleum Company p.l.c.
    Inventors: David W. Mellor, John W. A. Millar
  • Fracture investigation by resonance sweeping technique
    Patent number: 5093811
    Abstract: A method for determining the height and length of a fracture (2) in a borehole (1) involves generating pressure waves at closely spaced frequencies by means of a transmitter (3) at the wellhead. The response at the wellhead of the wellbore-fracture system to the resultant standing waves is measured by means of a transducer (6). A theoretical model of the wellbore-fracture system is generated and compared with the measured response to determine the height and length of the fracture.
    Type: Grant
    Filed: August 5, 1991
    Date of Patent: March 3, 1992
    Assignee: The British Petroleum Company p.l.c.
    Inventors: David W. Mellor, John W. A. Millar