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US 7,403,000 B2Granted
Apparatus and method of determining casing thickness and permeability
AssigneeBaker Hughes Incorporated
InventorsJoseph Gregory Barolak, Douglas W. Spencer, Jerry E. Miller, Bruce I. Girrell, Jason A. Lynch, Chris J. Walter
Life of this patent
Estimating the term…
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.
Claims19
An apparatus for evaluating a ferromagnetic tubular within a borehole, the apparatus comprising:
- (a) a tool conveyed in the borehole, the tool having at least one magnet configured to produce a magnetic flux in the tubular;
- (b) at least one multicomponent flux sensor responsive to magnetic flux and configured to provide an output indicative of an absolute thickness of the tubular;
- and
- (c) a processor configured to use the output of the at least one multicomponent flux sensor to determine the absolute thickness of the tubular by defining a mapping function between a first component and a second component of the output from the multicomponent flux sensor.
1 more element
A method of evaluating a ferromagnetic tubular within a borehole, the method comprising:
- (a) producing a magnetic flux in the tubular using at least one magnet on a tool conveyed in the borehole;
- (b) obtaining a signal indicative of an absolute thickness of the tubular using a multicomponent flux sensor;
- and
- (c) using the signal to estimate the absolute thickness of the tubular by defining a mapping function between a first component and a second component of the signal.
1 more element
A machine readable medium for use with an apparatus which evaluates a ferromagnetic tubular within a borehole, the apparatus including:
- (a) a tool configured to be conveyed within the tubular;
- (b) at least one magnet on the tool which is configured to produce a magnetic flux in the tubular;
- and
- (c) a multicomponent flux sensor responsive to magnetic flux;
- the medium comprising instructions that enable a processor to estimate from an output of the multicomponent flux sensor:
- (d) an absolute thickness of the tubular by defining a mapping function between a first and second component of the output from the multicomponent flux sensor;
- and
- (e) a magnetic permeability of the tubular.
5 more elements
Dependencies are inferred from the claim text.