Patents by Inventor Lawrence R. Bulduc

Lawrence R. Bulduc 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 inductively coupling signals between a downhole sensor and the surface
    Patent number: 5008664
    Abstract: An apparatus employing a set of inductive coils to transmit AC data and power signals between a downhole apparatus (which may include a sensor and a safety valve) and apparatus at the surface of the earth. In a preferred embodiment, the invention inductively couples a low frequency (less than 3 KHz) AC power signal from an outer wellhead coupler coil to an inner wellhead coupler coil wound around a tubing string. The AC signal propagates down a wireline conductor along the tubing string to a first downhole coupler coil (also wound around the tubing string) and is inductively coupled from the first downhole coupler coil to a second downhole coupler coil within the tubing. The power signal is preferably rectified, and then employed to power various items of downhole equipment. Data from a downhole sensor (whose frequency is preferably in the range from about 1.0 KHz to about 1.5 KHz) is impressed on the second downhole coil to modulate the AC power signal.
    Type: Grant
    Filed: January 23, 1990
    Date of Patent: April 16, 1991
    Assignee: Quantum Solutions, Inc.
    Inventors: Henry S. More, Edward C. Fraser, Lawrence R. Bulduc