Multi-variable workflow for cement sheath evaluation and characterization

Patent metadata

Field	Value
Publication number	US-9945974-B2
Application number	US-201514907620-A
Country	US
Kind code	B2
Filing date	Sep 4, 2015
Priority date	Sep 10, 2014
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

Sonic data, ultrasonic data, and density data of the annulus are obtained using a sonic tool, an ultrasonic tool, and a density tool, respectively, included in a tool string. A first deconvolution operation is performed to obtain an amplitude, a frequency, and a phase of the modified sonic wave. A first inverse modeling operation results in a first density value of the annular media. A second deconvolution operation is performed to obtain an amplitude, a frequency, and a phase of the modified ultrasonic wave. A second inverse modeling operation results in a second density value of the annular media. A third deconvolution operation is performed to obtain far counts, near counts, and an energy spectrum of gamma rays. A third inverse modeling operation results in a third density value of the annular media.

First claim

What is claimed is:

1. A method, comprising:
introducing a tool string into a wellbore at least partially lined with casing, wherein an annulus is defined between the casing and the wellbore and is filled with annular media;
obtaining sonic data of the annular media using a sonic wave emitted by a sonic tool included in the tool string;
obtaining, from the sonic data, an amplitude, a frequency, and a phase of the sonic wave as modified by the annular media;
performing a first inverse modeling operation using the amplitude, the frequency, and the phase to obtain a first density value of the annular media;
obtaining ultrasonic data of the annular media using an ultrasonic wave emitted by an ultrasonic tool included in the tool string;
obtaining, from ultrasonic data, an amplitude, a frequency, and a phase of the ultrasonic wave as modified by the annular media;
performing a second inverse modeling operation using the amplitude, the frequency, and the phase to obtain a second density value of the annular media;
obtaining density data of the annular media using a density tool included in the tool string;
obtaining, from the density data, far counts, near counts, and an energy spectrum of gamma rays scattered by the annular media;
performing a third inverse modeling operation using the far counts, the near counts, and the energy spectrum to obtain a third density value of the annular media; and
determining a bond quality between cement in the annular media and the casing based on the first, second, and third density values.

2. The method of claim 1 , further comprising performing the first inverse modeling operation based on an acoustic impedance characteristic of the annular media.

3. The method of claim 1 , further comprising performing the second inverse modeling operation based on an acoustic impedance characteristic of the annular media.

4. The method of claim 1 , further comprising comparing the first and second density values to determine whether the first and second density values are within a desired proximity of each other.

5. The method of claim 4 , further comprising obtaining a first casing-cement interface density from the first density value when the first and second density values are within the desired proximity, the first casing-cement interface density being a density value of the annular media at an interface of the casing and cement disposed within the annulus.

6. The method of claim 5 , further comprising performing the third inverse modeling operation using the first casing-cement interface density.

7. The method of claim 5 , further comprising obtaining the third density value based on the first casing-cement interface density.

8. The method of claim 7 , further comprising predicting a second casing-cement interface density from the third density value, the second casing-cement interface density being a density value of the annular media at the interface of the casing and the cement disposed within the annulus.

9. The method of claim 8 , further comprising comparing the first casing-cement interface density with the second casing-cement interface density to determine whether the first and second casing-cement interface densities are within a desired proximity of each other.

10. The method of claim 9 , further comprising recalculating at least one of the first density value and the second density value when the first and second casing-cement interface densities are not within a desired proximity of each other.

11. The method of claim 10 , further comprising obtaining a width of the interface of the casing and the cement based on the second casing-cement interface density when the first and second density values are within the desired proximity.

12. The method of claim 4 , further comprising recalculating at least one of the first density value and the second density value when the first and second density values are not the desired proximity.

13. A well system, comprising:
a tool string conveyable into a wellbore drilled through one or more subterranean formations and at least partially lined with casing, wherein an annulus is defined between the casing and the wellbore and filled with annular media and the tool string includes at least a sonic tool, an ultrasonic tool, and a density tool; and
a computer system including a processor and a non-transitory computer readable medium, the computer system being communicatively coupled to the tool string and the computer readable medium storing a computer readable program code that, when executed by the processor, configures the processor to:
operate the sonic tool to obtain sonic data of the annular media using a sonic wave emitted by the sonic tool;
obtain, from the sonic data, an amplitude, a frequency, and a phase of the sonic wave as modified by the annular media;

perform a first inverse modeling operation using the amplitude, the frequency, and the phase to obtain a first density value of the annular media;
operate the ultrasonic tool to obtain ultrasonic data of the annular media using an ultrasonic wave emitted by the ultrasonic tool;
obtain, from the ultrasonic data, obtain an amplitude, a frequency, and a phase of the ultrasonic wave as modified by the annular media;
perform a second inverse modeling operation using the amplitude, the frequency, and the phase to obtain a second density value of the annular media;
operate the density tool to obtain density data of the annular media using gamma rays emitted by the density tool;
obtain, from the density data, far counts, near counts, and an energy spectrum of gamma rays scattered by the annular media;
perform a third inverse modeling operation using the far counts, the near counts, and the energy spectrum to obtain a third density value of the annular media; and

determining a bond quality between cement in the annular media and the casing based on the first, second, and third density values.

14. The system of claim 13 , wherein the processor is further configured to perform the first inverse modeling operation based on an acoustic impedance characteristic of the annular media.

15. The system of claim 13 , wherein the processor is further configured to perform the second inverse modeling operation based on an acoustic impedance characteristic of the annular media.

16. The system of claim 13 , wherein the processor is further configured to compare the first and second density values to determine whether the first and second density values are within a desired proximity of each other, and obtain a first casing-cement interface density from the first density value when the first and second density values are within the desired proximity, the first casing-cement interface density being a density value of the annular media at an interface of the casing and cement disposed within the annulus.

17. The system of claim 16 , wherein the processor is further configured to perform the third inverse modeling operation using the first casing-cement interface density.

18. The system of claim 16 , wherein the processor is further configured to obtain the third density value based on the first casing-cement interface density.

19. The system of claim 18 , wherein the processor is further configured to predict a second casing-cement interface density from the third density value, the second casing-cement interface density being a density value of the annular media at the interface of the casing and the cement disposed with in the annulus, and compare the first casing-cement interface density with the second casing-ceme

Assignees

• Halliburton Energy Services Inc

Inventors

• Quintero Luis F
• Foianini Ivo
• Fadul Javier

Classifications

• G01V1/48 Primary

  Processing data · CPC title

• G01V2210/6226

  Impedance · CPC title

• G01V11/00

  Prospecting or detecting by methods combining techniques covered by two or more of main groups G01V1/00 - G01V9/00 · CPC title

• G01V5/12

  using gamma or X-ray sources {(gamma sources using isotopes G21G4/00; X-ray tubes H01J35/00)} · CPC title

• G01V2210/6224

  Density · CPC title