# US 11,306,577 B2 · Calibrating electromagnetic corrosion detection tools via core saturation

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- Number: US 11,306,577 B2
- Document ID: US11306577B2
- Status: Granted
- Kind: B2
- Application number: 16/077,486
- Filed: 2017-06-08
- Published: 2021-07-01
- Granted: 2022-04-19
- Earliest claimed: 2017-06-08
- Assignees: Halliburton Energy Services, Inc.
- Applicants: Halliburton Energy Services, Inc.
- Inventors: Burkay Donderici; Ahmed E. Fouda
- Web page: https://patentgrep.com/patent/US11306577B2

## CPC

- E21B 47/006: {Detection of corrosion or deposition of substances}
- G01V 13/00: Manufacturing, calibrating, cleaning, or repairing instruments or devices covered by groups G01V1/00 – G01V11/00
- G01N 17/006: {of metals}
- G01N 17/04: Corrosion probes
- G01N 27/90: using eddy currents
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02)
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

Methods and devices used to calibrate EM corrosion detection tools may estimate the effects of the presence of a core on measurements to enable more accurate corrosion detection in the well line. The methods may involve sending voltages to a core of a well tool disposed in the well line to obtain signals while the core is in a saturated and unsaturated state. Subsequent measurements using the core may be calibrated using a constant resulting from the division of the signals achieved at the core in the saturated and unsaturated states.

## Claims

### Claim 1

A well line detection method comprising the steps of:
applying a first voltage at a core of a well tool disposed in the well line;
logging at least one first signal using the well tool while the first voltage is applied to the core;
removing the first voltage from the core of the well tool while the tool is disposed in the well line;
logging at least one second signal using the well tool while the first voltage is removed from the core; and
calibrating at least one measurement using both the first signal and the second signal to take into account and/or compensate for the effect of the core.

### Claim 2 (depends on 1)

The well line detection method of claim 1, wherein calibrating comprises taking a product of the at least one measurement and one or more of the at least one first signal divided by one or more of the at least one second signal.

### Claim 3 (depends on 2)

The well line detection method of claim 2, wherein the first voltage is applied at DC frequency.

### Claim 4 (depends on 1)

The well line detection method according to claim 1, further comprising the step of determining at least one of a defect, well line thickness, well line diameter, well line magnetic permeability, well line electrical properties, and well line metal content.

### Claim 5 (depends on 4)

The well line detection method of claim 4, wherein the defect comprises corrosion in the well line.

### Claim 6 (depends on 4)

The well line detection method of claim 4, wherein the calibrating step further comprises an average of a plurality of first signals.

### Claim 7 (depends on 4)

The well line detection method of claim 4, wherein the calibrating step further comprises an average of a plurality of second signals.

### Claim 8 (depends on 4)

The well line detection method of claim 4, wherein the at least one measurement using a product of an average of a plurality of first signals divided by an average of a plurality of second signals.

### Claim 9 (depends on 4)

The well line detection method of claim 4, further comprising demagnetizing the core of the well tool.

### Claim 10 (depends on 9)

The well line detection method of claim 9, wherein the demagnetizing step takes place after removal of the first voltage.

### Claim 11 (depends on 4)

The well line detection method of claim 4, wherein the at least one measurement is made in the frequency domain.

### Claim 12 (depends on 4)

The well line detection method of claim 4, wherein the at least one measurement is made in the time domain.