Optimizing eddy current measurement to save power

• US 10,444,190 B2
• Filed: 07/13/2015
• Issued: 10/15/2019
• Est. Priority Date: 07/12/2014
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Khalaj Amineh, Reza, Dondericl, Burkay, San Martin, Luis Emilio
• Primary Examiner(s): Nguyen, Vinh P
• Application Number:
  US15/315,339
• Publication Number:
  US 20170131239A1
• Time in Patent Office: 1,555 Days
• CPC Class Codes: E21B 41/02 in situ inhibition of corrosion in boreholes or wells
• CPC Class Codes: E21B 47/007 Measuring stresses in a pipe string or casing for locating blocked portions of pipes E21B47/09
• CPC Class Codes: G01B 7/10 using magnetic means, e.g. by measuring change of reluctance
• CPC Class Codes: G01N 27/9006 Details, e.g. in the structure or functioning of sensors
• CPC Class Codes: G01N 27/9046 by analysing electrical signals
• CPC Class Codes: G01V 3/28 using induction coils

Abstract

A method for optimizing eddy current measurements includes conveying an electromagnetic tool through a borehole. The method further includes transmitting an excitation signal from the tool. The method further includes recording an eddy current response to the excitation signal from one or more tubings and casings within the borehole before the fall time of the excitation signal.

Claims

1. A method for optimizing eddy current measurements comprising:

conveying an electromagnetic tool through a borehole;

transmitting, from the electromagnetic tool, an excitation signal;

monitoring a magnitude of the excitation signal with respect to an error band; and

recording an eddy current response to the excitation signal from one or more tubings and casings within the borehole before the excitation signal falls;

wherein recording the eddy current response comprises recording the eddy current response based on the excitation signal settling within the error band.

2. The method of claim 1, wherein recording the eddy current response comprises recording the eddy current response during transmission of the excitation signal.

3. The method of claim 1, wherein recording the eddy current response comprises activating a receiving coil on the electromagnetic tool during transmission of the excitation signal.

6. The method of claim 1, further comprising recording the eddy current response after a fall time of the excitation signal.

7. The method of claim 1, further comprising modifying the excitation signal using a ratio of the eddy current response at multiple frequencies.

4. A method for optimizing eddy current measurements comprising:

conveying an electromagnetic tool through a borehole;

transmitting, from the electromagnetic tool, an excitation signal; and

recording an eddy current response to the excitation signal from one or more tubings and casings within the borehole before the excitation signal falls; and

monitoring a magnitude of the excitation signal with respect to an error band comprising a maximum range of magnitudes between any local maximum magnitude and the next local minimum magnitude, or any local minimum magnitude and the next local maximum magnitude, wherein recording the eddy current response comprises recording the eddy current response based on the excitation signal settling within the error band.

5. The method of claim 4, further comprising ceasing transmission of the excitation signal after the excitation signal settles within the error band.

8. A method for optimizing eddy current measurements comprising:

conveying an electromagnetic tool through a borehole;

transmitting, from the electromagnetic tool, an excitation signal;

monitoring an eddy current response to the excitation signal from one or more tubings and casings within the borehole during transmission of the excitation signal;

recording the eddy current response; and

modifying the excitation signal based on the eddy current response to save power during transmission of the excitation signal, wherein the modifying the excitation signal comprises omitting one or more frequencies in the excitation signal.

9. The method of claim 8, wherein monitoring the eddy current response comprises identifying one or more frequencies at which the eddy current response is below a threshold and wherein modifying the excitation signal comprises omitting the one or more frequencies at which the eddy current response is below the threshold from the excitation signal.

10. The method of claim 8, wherein the excitation signal comprises a zero direct current waveform.

11. The method of claim 8, wherein monitoring the eddy current response comprises monitoring the magnitude of the excitation signal with respect to an error band comprising a maximum range of magnitudes between any local maximum magnitude and the next local minimum magnitude, or any local minimum magnitude and the next local maximum magnitude, and further comprising recording the eddy current response based on the excitation signal settling within the error band.

12. The method of claim 11, further comprising ceasing transmission of the excitation signal after the excitation signal settles within the error band.

13. The method of claim 8, further comprising:

transmitting, from the electromagnetic tool, an assessment signal comprising frequency that varies with time;

obtaining an eddy current response to the assessment signal from one or more tubings and casings within the borehole; and

identifying one or more frequencies at which the eddy current response to the assessment signal is above a threshold;

wherein transmitting the excitation signal comprises transmitting the excitation signal comprising only the one or more frequencies at which the eddy current response to the assessment signal is above the threshold.

14. The method of claim 8, wherein modifying the excitation signal comprises modifying the excitation signal using a ratio of the eddy current response at multiple frequencies.