Patents by Inventor Gerald J. Crawford

Gerald J. Crawford 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).

  • Method of placing magnetic markers on collarless cased wellbores
    Patent number: 4572293
    Abstract: To locate wireline tools in wellbores using collarless or butt joint casing, a magnetic marker is applied at selected positions on the casing before or after placing the casing in a well, such marker being capable of being located by a conventional casing collar locator. Apparatus to apply the marker is also shown.
    Type: Grant
    Filed: August 31, 1984
    Date of Patent: February 25, 1986
    Assignee: Standard Oil Company (now Amoco Corporation)
    Inventors: James G. Wilson, Gerald J. Crawford