Detecting downhole sand ingress locations

Patent metadata

Field	Value
Publication number	US-11530606-B2
Application number	US-201716091519-A
Country	US
Kind code	B2
Filing date	Apr 6, 2017
Priority date	Apr 7, 2016
Publication date	Dec 20, 2022
Grant date	Dec 20, 2022

Abstract

A method of detecting sand inflow into a wellbore is disclosed. The method can include obtaining a sample data set, detecting a broadband signal within the sample data set, comparing the broadband signal with a signal reference, determining that the broadband signal meets or exceeds the signal reference, and determining the presence of sand inflow into the wellbore based on determining that the broadband signal meets or exceeds the signal reference. The sample data set can be a sample of an acoustic signal originating within a wellbore including a fluid, and the broadband signal at least includes a portion of the sample data set at frequencies above 0.5 kHz.

First claim

We claim:

1. A system of detecting sand inflow into a wellbore, the system comprising:
a processor unit comprising a processor and a memory, wherein the processor unit is adapted for signal communication with a receiver, and wherein the memory comprises an analysis application, that when executed on the processor, configures the processor to:
receive, from the receiver, a sample data set, the sample data set being a sample of an acoustic signal from a wellbore that comprises a fluid;
detect a broadband signal within the sample data set, wherein the broadband signal at least includes a portion of the sample data set at frequencies above 0.5 kHz;
compare the broadband signal with a signal reference;
determine that the broadband signal meets or exceeds the signal reference;
determine the presence of sand inflow into the wellbore based on determining that the broadband signal meets or exceeds the signal reference; and
provide an output indicative of the determination of the presence of the sand inflow.

2. The system of claim 1 , wherein the analysis application, when executed on the processor, further configures the processor to:
determine a spectral centroid of the sample data set;
determine a spectral spread of the sample data set;
determine that, where the sample data set for which the spectral centroid is determined comprises optical data indicative of the acoustic signal, the spectral centroid is greater than the spectral centroid threshold, or, where the sample data set for which the spectral centroid is determined comprises the derivative of said optical data, the spectral centroid is less than the spectral centroid threshold;
determine that the spectral spread is greater than a spectral spread threshold; and
determine the inflow of sand into the wellbore based on determining that, where the sample data set for which the spectral centroid is determined comprises said optical data, the spectral centroid is greater than the spectral centroid threshold, or, where the sample data set for which the spectral centroid is determined comprises said derivative of said optical data, the spectral centroid is less than the spectral centroid threshold and determining that the spectral spread is greater than a spectral spread threshold.

3. The system of claim 1 , wherein the analysis application, when executed on the processor, further configures the processor to:
frequency filter the sample data set into a plurality of frequency bands, wherein at least one frequency band of the plurality of frequency bands comprises frequencies greater than about 0.5 kHz wherein the signal reference comprises a baseline acoustic signal; and
wherein the determination that the broadband signal meets or exceeds the signal reference comprises a determination that frequencies in the at least one frequency band comprising frequencies greater than about 0.5 kHz have an intensity greater than corresponding frequencies in the same at least one frequency band of the baseline acoustic signal.

4. The system of claim 3 , wherein the analysis application, when executed on the processor, configures the processor to: obtain the baseline acoustic sample data set while the wellbore is shut in.

5. The system of claim 1 , wherein the receiver is coupled to a distributed acoustic sensor disposed in the wellbore, wherein the distributed acoustic sensor system comprises an optical fiber disposed alone at least a portion of a length of the wellbore, and wherein the receiver is optically coupled to the optical fiber.

6. The system of claim 1 , wherein the analysis application further configures the processor to:
filter the sample data set within a predefined frequency range to produce a second data set in response to determining that the spectral centroid is greater than a spectral centroid threshold and in response to determining that the spectral spread is greater than a spectral spread threshold;
determine a spectral energy of the second data set; and
determine an amount of sand inflow into the wellbore at a defined depth based on the spectral energy.

7. The system of claim 1 , further comprising an output device, wherein the analysis application further configures the processor to:
generate a log of a plurality of spectral energies at a plurality of depths along the wellbore; and
display a sand log illustrating the plurality of spectral energies at the plurality of depths.

8. The system of claim 1 , further comprising an output device, wherein the analysis application further configures the processor to:
display time-lapsed sand logs that visualize sanding at discrete periods of time.

9. The system of claim 1 , wherein the analysis application further configures the processor to:
determine a spectral centroid of the sample data set;
determine a spectral spread of the sample data set;
wherein the signal reference comprises a spectral centroid threshold and a spectral spread threshold, and wherein determining that the broadband signal meets or exceeds the signal reference comprises determining a difference between the spectral centroid and the spectral centroid threshold and determining that the spectral spread is greater than the spectral spread threshold; and

wherein determining the presence of sand inflow into the wellbore based on determining that the broadband signal meets or exceeds the signal reference comprises determining the presence of sand inflow into the wellbore based on determining the difference between the spectral centroid and the spectral centroid threshold and determining that the spectral spread is greater than a spectral spread threshold.

10. The system of claim 9 , wherein the sample data set for which the spectral centroid is determined comprises optical data indicative of the acoustic signal, and wherein the analysis application further configures the processor to:
determine a zero or positive difference between the spectral centroid and the spectral centroid threshold and the determination that the spectral spread is greater than the spectral spread threshold indicates that the signal reference is met or exceeded.

11. The system of claim 9 , wherein the sample data set on which the spectral centroid is determined comprises a derivative of said optical data, and wherein the analysis application further configures the processor to:
determine a zero or negative difference between the spectral centroid and the spectral centroid threshold and the determination that the spectral spread is greater than the spectral spread threshold indicates that the signal reference is met or exceeded.

12. The system of claim 1 , wherein the analysis application further configures the processor to:
filter the acoustic signal using a spatial filter to obtain the sample data set, wherein the sample data set is indicative of an acoustic sample over a defined depth in the wellbore.

13. The system of claim 1 , wherein the acoustic signal is detected within the wellbore while the fluid is being produced from the wellbore.

14. The system of claim 1 , wherein the sample data set is representative of the acoustic signal across a frequency spectrum, and wherein the analysis application further configures the processor to:
determine a plurality of frequency domain features of the sample data set;
wherein the determination of the presence of the sand inflow into the wellbore is based on a determination that the plurality of frequency domain features match a sand ingress signature; and
estimate a qualitative indication of a concentration of sand at one or more locations within the wellbore.

15. The system of claim 14 , wherein the ana

Assignees

• Bp Exploration Operating Co Ltd

Inventors

• Langnes Tommy
• Thiruvenkatanathan Pradyumna

Classifications

• E21B49/00

  Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells · CPC title

• G01V1/50

  Analysing data · CPC title

• G01H3/04

  Frequency · CPC title

• E21B47/107 Primary

  using acoustic means · CPC title

• E21B43/14

  Obtaining from a multiple-zone well · CPC title