Method for measuring remote field eddy current thickness in multiple tubular configuration

• US 9,310,338 B2
• Filed: 10/11/2011
• Issued: 04/12/2016
• Est. Priority Date: 10/14/2010
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Yarbro, Gregory Scott, Li, Jing, Bittar, Michael
• Primary Examiner(s): Hollington, Jermele M
• Assistant Examiner(s): Rajaputra, Suresh K
• Application Number:
  US13/878,553
• Publication Number:
  US 20130193953A1
• Time in Patent Office: 1,645 Days
• US Class Current: 1/1
• CPC Class Codes: E21B 47/085 using radiant means, e.g. acoustic, radioactive or electromagnetic
• CPC Class Codes: G01B 7/10 using magnetic means, e.g. by measuring change of reluctance
• CPC Class Codes: G01N 27/9066 by measuring the propagation time, or delaying the signals
• CPC Class Codes: G01N 33/20 Metals
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005

Abstract

In accordance with aspects of the present invention, a method of inspecting a well tubular is disclosed. The method utilizes a probe with a transmitter and detectors spaced from the transmitter by at least twice the diameter of the pipe to be tested. In some cases where multi-tubular structures are tested, the probe can include further detectors spaced from the transmitter by at least twice the diameter of the outer pipes as well. The phase of signals detected by the detectors relative to the transmitter are utilized to detect faults in the pipes.

Claims

1. A method of inspecting a pipe, comprising:

lowering a probe into a first pipe, the first pipe being concentrically placed within a second pipe, the probe including a transmitter, a first detector separated from the transmitter by a first distance equal to or greater than twice a diameter of the first pipe, and a second detector separated from the transmitter by a second distance equal to or greater than a diameter of the second pipe;

providing a driving signal to the transmitter;

receiving a first detector signal from the first detector;

receiving a second detector signal from the second detector;

determining a first phase shift between the first detector signal and the driving signal;

determining a second phase shift between the second detector signal and the driving signal;

determining a wall thickness of the first pipe from the first phase shift;

determining a total wall thickness from the second phase shift; and

subtracting the wall thickness of the first pipe from the total wall thickness to determine a wall thickness of the second pipe.

2. The method of claim 1, further including monitoring one of the first phase shift and the second phase shift as a function of location in the pipe.

3. The method of claim 1, further comprising:

modeling a response of the probe to known defect; and

determining a fault in one of the first pipe and the second pipe based on one of the first phase shift and the second phase shift.

4. The method of claim 3, wherein modeling a response includes providing a predicted response based on a length of the defect and dimensions of the probe.

5. The method of claim 1, wherein the probe further includes a magnetic field generator and the method further includes

generating a base log from the phase shift as a function of location in the pipe as the probe is lowered into the pipe;

and

generating a partial saturation log from the phase shift as a function of location in the pipe as the probe is raised in the pipe.

6. A method of determining thickness of a pipes in a multi-pipe configuration, comprising:

lowering a probe into the multi-pipe configuration, the probe including

a transmitter,

at least one first detector spaced from the transmitter by a distance greater than a first diameter of a first pipe of the multi-pipe configuration and less than a second diameter of a second pipe of the multi-pipe configuration, and

at least one second detector spaced from the transmitter by a distance greater than the second diameter;

measuring a first phase shift from the at least one first detector;

measuring a second phase shift from the at least one second detector;

determining a first wall thickness of the first pipe from the first phase shift;

determining a combined wall thickness from the second phase shift; and

determining a second wall thickness from the difference between the combined wall thickness and the first wall thickness.

7. A system for testing a first and second pipes, the first pipe being concentrically disposed within the second pipe, the system comprising:

a probe including a transmitter, a first detector separated from the transmitter by a first distance at least twice that of the inner diameter of the first pipe, a second detector separated from the transmitter by a second distance at least twice that of the inner diameter of the second pipe; and

a processor coupled to the transmitter and the first and second detectors and operable to determine first and second phase shifts of signals received at the first and second detectors, respectively, relative to a signal transmitted by the transmitter and to determine a wall thickness of the first pipe from the first phase shift, a combined wall thickness from the second phase shift, and a wall thickness of the second pipe from a difference between the combined wall thickness and the first wall thickness.

8. The system of claim 7, further comprising:

a transmitter driver coupled to the transmitter; and

a detection circuit coupled to one of the first and second detectors.

9. The system of claim 8, further including an interface to a computer, the computer operable for determining a fault based on the first and second phase shifts and a model of a predicted response of the probe to a known defect.

10. The system of claim 7 further comprising a cable controller coupled to the processor, the cable controller operable for controlling the position of the probe in the first pipe.

11. The system of claim 7 wherein the probe further includes a magnetic field generator separated from the transmitter and the first and second detectors.

12. The system of claim 11, wherein the magnetic field generator includes a permanent magnet.

13. The system of claim 11, wherein the magnetic field generator includes a coil driving by a current.