Kenneth Gary Riggs

US Patent:

56708785, Sep 23, 1997

Filed:

Jun 21, 1993

Appl. No.:

8/080295

Inventors:

Keith W. Katahara - Allen TX
Pedro F. Lara - Dallas TX
Kenneth R. Riggs - Richardson TX

Assignee:

Atlantic Richfield Company - Los Angeles CA

International Classification:

G01N 2772
G01N 2782
G01R 3312

US Classification:

324221

Abstract:

There is provided a transient electromagnetic method and apparatus for inspecting objects. The apparatus includes a sensing portion, which has a transmitting antenna and at least one receiving antenna thereon. The sensing portion is located adjacent to the object which is to be inspected such that the antennas are adjacent to the object. There is also a magnet located adjacent to the sensing portion. The magnet has poles located adjacent to the object, so as to provide a steady-state magnetic field to the object. By applying a steady-state magnetic field to the object during inspection, increased inspection speeds and improved spatial resolutions can be achieved. In addition, casing can be inspected from inside of tubing.