Algorithm for zonal fault detection in a well environment

Patent metadata

Field	Value
Publication number	US-9394784-B2
Application number	US-201314145307-A
Country	US
Kind code	B2
Filing date	Dec 31, 2013
Priority date	Apr 2, 2007
Publication date	Jul 19, 2016
Grant date	Jul 19, 2016

Abstract

A hydrocarbon well (e.g., oil well) may be monitored during to determine whether a fault exists during an operation such as injecting sealant (e.g., cement) into the borehole. RFID tags may be mixed in a wellbore fluid (e.g., drilling mud, cement, etc.), placed into a borehole, and then tracked within the borehole by communication assemblies with RFID sensors. Data may be obtained by interrogating RFID tags in one or more azimuthally oriented regions of an annulus surrounding a casing of the borehole. Fluid distribution in the annulus will be evaluated with respect to azimuthally offset regions of the annulus.

First claim

What is claimed is:

1. A method, comprising:
placing a first fluid into an annulus surrounding a casing in a borehole, the first fluid containing a first plurality of radio frequency identification device (RFID) tags;
monitoring a plurality of azimuthally offset regions of the annulus for individual tags of the first plurality of RFID tags, the plurality of azimuthally offset regions including a first azimuthal region and a second azimuthal region at least partially offset from the first azimuthal region;
detecting during a first time period, a number of the first plurality of RFID tags in the first azimuthal region; and
detecting during a second time period, a number of the first plurality of RFID tags in the second azimuthal region.

2. The method of claim 1 , further comprising evaluating a volume of the first fluid proximate the first azimuthal region based in part on the number of RFID tags of the first plurality of RFID tags detected in the second azimuthal region.

3. The method of claim 1 , further comprising:
placing a second fluid into the annulus, the second fluid containing a second plurality of RFID tags, the second plurality of RFID tags providing a different response to interrogation than the first plurality of RFID tags;
monitoring a plurality of the azimuthally offset regions of the annulus for individual tags of the second plurality of RFID tags;
detecting during a third time period, a number of the second plurality of RFID tags in the first azimuthal region; and
detecting during a fourth time period, a number of the first plurality of RFID tags in the second azimuthal region.

4. The method of claim 3 , wherein the third and fourth time periods are the same time period.

5. The method of claim 3 , further comprising evaluating a volume of the first fluid proximate the first azimuthal region based in part on the number of RFID tags of the second plurality of RFID tags detected in the second azimuthal region.

6. The method of claim 1 , wherein the first and second azimuthal regions are within a specified vertical distance from one another along the casing.

7. The method of claim 6 , wherein the first and second regions are at substantially the same depth location along the casing.

8. The method of claim 1 , wherein the first and second time periods are different time periods.

9. The method of claim 1 , wherein the first fluid comprises a sealant.

10. A method of identifying faults in a sealant in a well annulus, comprising:
placing sealant in an annulus surrounding casing in a borehole, the sealant containing a plurality of radio frequency identification device (RFID) tags;
monitoring for the RFID tags in a plurality of azimuthal regions of the annulus at each of a plurality of depths along the casing;
detecting the number of RFID tags present within each azimuthal region at a first depth along the casing within a respective first time period;
evaluating the detected number of RFID tags at the first depth at each azimuthal region to identify if faults exist in the sealant distribution at the first depth.

11. The method of claim 10 , wherein the evaluating of the detected number of RFID tags comprises comparing the number of detected tags in a first azimuthal region to the detected tags in another azimuthal region proximate the same depth along the casing.

12. The method of claim 10 , further comprising:
detecting the number of RFID tags present within each azimuthal region at a second depth along the casing within a second time period; and
evaluating the detected number of RFID tags at each azimuthal region at the second depth to identify if a possible faults exists in the sealant distribution at the second depth.

13. The method of claim 10 , wherein evaluating the detected number of tags identifies that a possible fault exists in the sealant distribution, and wherein the method further comprises providing a notification associated with the possible fault.

14. The method of claim 10 , further comprising:
using a plurality of additional sensors configured to monitor a physical parameter of a material in the well annulus at a plurality of azimuthal regions of the annulus at each of a plurality of depths along the casing; and
evaluating the sensed parameters at each azimuthal region at a second depth to identify if a possible fault exists at the second depth.

15. The method of claim 10 , wherein evaluating the detected number of RFID tags at the first depth at each azimuthal region comprises making a measurement indicative of a difference between the number of RFID tags detected in a first azimuthal region and the number of RFID tags detected in at least one other azimuthal region proximate the first depth.

16. The method of claim 10 , wherein the number of RFID tags in an azimuthal region of the annulus provides a measure of the volume of sealant in the first azimuthal region.

17. The method of claim 14 , wherein the additional sensors comprise MEMS sensors in the RFID tags.

18. The method of claim 14 , wherein the RFID sensors are part of a communication assembly coupled in the casing string, and wherein the additional sensors are also part of the communication assembly.

19. A system, comprising:
a plurality of communication assemblies arranged in spaced relation along a casing string, each communication assembly having a plurality of RFID sensors configured to detect RFID tags contained with a sealant in the well annulus surrounding the casing in a borehole in a plurality of azimuthally offset regions of the annulus proximate the depth of the respective communication assembly; and
a controller configured to,
cause the RFID sensors in a communication assembly to detect the number of RFID tags in the plurality of azimuthally offset regions of the annulus proximate a communication assembly during one or more time intervals, and
compare the detected number of RFID tags in a first azimuthal region of the annulus to the detected number of RFID tags in at least one other azimuthal region of the annulus.

20. The system of claim 19 , wherein the controller comprises at least one processor.

21. The system of claim 19 , wherein the controller is located within the communication assembly.

22. The system of claim 20 , wherein at least one processor is located at a surface location.

Assignees

• Halliburton Energy Services Inc

Inventors

• Roberson Mark W
• Goodwin Scott
• Roddy Craig W
• Ravi Krishna M

Classifications

• E21B47/005

  Monitoring or checking of cementation quality or level · CPC title

• E21B43/25

  Methods for stimulating production {(by vibrating earth formations E21B43/003)} · CPC title

• E21B33/13

  Methods or devices for cementing, for plugging holes, crevices or the like · CPC title

• E21B47/13

  by electromagnetic energy, e.g. radio frequency · CPC title

• E21B47/10 Primary

  Locating fluid leaks, intrusions or movements · CPC title