BINARIZATION TECHNIQUE FOR ACOUSTIC DATA ANALYSIS

• US 20080162058A1
• Filed: 05/23/2007
• Published: 07/03/2008
• Est. Priority Date: 12/28/2006
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: Wago, Toshimichi, Adnan, Sarmad, Baklanov, Nikolay
• Granted Patent: US 7,643,945 B2
• Time in Patent Office: Days
• US Class Current: 702/48
• CPC Class Codes: F04B 2201/0802 Vibration
• CPC Class Codes: F04B 51/00 Testing machines, pumps, or pumping installations
• CPC Class Codes: G01M 3/24 using infrasonic, sonic, or ultrasonic vibrations

Abstract

A method of enhancing acoustic pump data for monitoring of pump condition in operation. The enhancement may be in the form of a substantial reduction in the amount of data to be processed by firmware to a much more manageable level. This may be achieved through pre-filtering of acquired acoustic data, computing frequency moments, and by application of a median filter to the acoustic data. Regardless, a binarization technique that uses features vector including but not limited to double-threshold derived from statistics of enhanced amplitudes, may be employed whereby enhanced acoustic data is boiled down to a series of potential acoustic events of particular widths. These widths may represent a duration of each acoustic event and be checked for correlation with the speed of the operating speed of the pump. Acoustic events that correlate with an operating speed of the pump may represent an unhealthy condition of the pump such as where the width is about the duration of one half of a cycle of the pump and a leaky pump valve presents itself for this same period of time.

Claims

1. A method of analyzing acoustic data of a pump, the method comprising:

operating the pump at a given speed;

recording the acoustic data from the pump during said operating;

enhancing the acoustic data for binarization; and

binarizing the acoustic data for identifying any acoustic event correlating with the speed.

2. The method of claim 1 wherein said binarizing comprises determining a width of any acoustic event, the width representing a duration of the acoustic event, the method further comprising employing a processor to compare information regarding the speed and the duration for the identifying.

3. The method of claim 2 wherein the duration is about half a stroke of the operating pump to indicate a valve leak in the pump.

4. The method of claim 2 further comprising establishing upper and lower thresholds of magnitude for the enhanced acoustic data prior to said binarizing.

5. The method of claim 4 further comprising:

noting a beginning of an acoustic event once a magnitude of the enhanced acoustic data crosses the upper threshold from below the lower threshold; and

noting an end of the acoustic event once the magnitude of the enhanced acoustic data crosses the lower threshold from above the upper threshold, the width defined by the distance between the beginning and the end.

6. The method of claim 4 wherein said establishing comprises applying a histogram technique to the enhanced acoustic data.

7. The method of claim 1 wherein said recording is of a predetermined frequency range.

8. The method of claim 1 wherein said recording occurs via an acoustic sensor coupled to a white noise filter.

9. The method of claim 1 wherein said recording is established over a plurality of frequency zones for independent analyses thereof.

10. The method of claim 1 wherein said recording is of multiple cycles of the operating pump, the method further comprising averaging acoustic data of the multiple cycles to minimize an effect of any inconsistent acoustics.

11. The method of claim 10 wherein said averaging includes stacking of independent waveforms for presentation.

12. The method of claim 1 wherein said enhancing comprises amplifying a magnitude of the acoustic data over a frequency range.

13. The method of claim 1 wherein said enhancing comprises smoothing a presentation of the acoustic data with one of weighted exponential averaging and an FIR implementation of a Hilbert transform.

14. The method of claim 12 wherein said amplifying is applied over the frequency range in one of a linear manner and an exponential manner.

15. The method of claim 12 wherein said amplifying is applied to a greater degree at a higher end of the frequency range to enhance a presentation of the acoustic data resulting from an early stage valve leak in the pump.

16. A method of analyzing acoustic data of a pump, the method comprising:

operating the pump;

recording the acoustic data from the pump in a predetermined frequency range during said operating;

amplifying a magnitude of the acoustic data over the frequency range with subsequent eliminating of frequency dimension through its integration;

enhancing the amplified magnitude of the acoustic data by application of a median filter, said recording in the predetermined frequency range and said enhancing to reduce storage of the acoustic data this is noise.

17. The method of claim 16 wherein the predetermined frequency range is between about 1 KHz and about 25 KHz.

18. The method of claim 16 wherein said recording occurs over periods of at least about 4/3 of a cycle of the operating pump.

19. The method of claim 16 wherein said operating is at a known speed, the method further comprising binarizing the acoustic data for identifying any acoustic event correlating with the speed.

20. An oilfield pump assembly comprising:

a pump for operating at a given speed;

an acoustic sensor coupled to said pump for acquiring acoustic data therefrom during said operating; and

a processor coupled to said acoustic sensor for acquiring information regarding the acoustic data and the speed, said processor to identify any acoustic event correlating with the speed via binarization of the acoustic data.

21. The oilfield pump assembly of claim 20 wherein the acoustic event is an unhealthy condition of the pump.

22. The oilfield pump assembly of claim 21 wherein said pump further comprises a valve seal disposed therein, the unhealthy condition being a leak in said valve seal.

23. The oilfield pump assembly of claim 22 wherein the unhealthy condition of the leak is identified by an acoustic event persisting for about the duration of one half of a stroke of the pump.

24. The oilfield pump assembly of claim 20 wherein said pump is of a triplex configuration for a fracturing operation.