Abstract: A casing inspection device with magnets and flux sensors. The sensors provide measurements of absolute levels of magnetic flux that are indicative of changes in casing thickness and/or permeability.
Type:
Grant
Filed:
March 11, 2005
Date of Patent:
July 22, 2008
Assignee:
Baker Hughes Incorporated
Inventors:
Joseph Gregory Barolak, Douglas W. Spencer, Jerry E. Miller, Bruce I. Girrell, Jason A. Lynch, Chris J. Walter
Abstract: The invention is a method and apparatus for determining an electrical property a formation surrounding a borehole with a measuring-while-drilling device. The apparatus an antenna configuration disposed along the outer face of an extendable stabilizer joined to a rotatable drill collar. Typically, two receivers and two transmitters are spaced along the longitudinal axis of the drill collar, with the two receivers spaced symmetrically in between the two transmitters. Alternatively, receivers and transmitters can be spaced along the circumference, possibly over multiple stabilizers. Multiple assemblies can be used. Data can be obtained with the transmitter-receiver assembly held in a stationary position or rotating circumferentially. Apparatus can be operated in a “broadside” configuration, an “endfire” configuration, or a configuration in which transmitter coils and receiver coils are oriented orthogonally to each other.
Type:
Grant
Filed:
July 8, 2003
Date of Patent:
October 25, 2005
Assignee:
Baker Hughes Incorporated
Inventors:
Roland E. Chemali, Martin Folberth, Tsili Wang, Rene Ritter