Distributed sound speed measurements for multiphase flow measurement

• US 6,601,458 B1
• Filed: 03/07/2000
• Issued: 08/05/2003
• Est. Priority Date: 03/07/2000
• Status: Expired due to Term

• Current Assignee: Weatherford Technology Holdings, LLC (Weatherford International PLC)
• Original Assignee: Weatherford/Lamb Incorporated (Weatherford International PLC)
• Inventors: Gysling, Daniel L., Myers, Mark R.
• Primary Examiner(s): NOORI, MAX H
• Application Number:
  US09/519,785
• Time in Patent Office: 1,246 Days
• Field of Search: 738/610.4, 738/610.5, 738/611.8, 738/612.5, 738/612.6, 738/612.7, 738/612.8, 738/612.9, 738/613.1
• US Class Current: 73/861.04
• CPC Class Codes: G01F 1/74 Devices for measuring flow of a fluid or flow of a fluent solid material in suspension in another fluid

Abstract

A multiphase flow meter is presented based on distributed sensors that provide data pertaining to temperature, pressure, phase fraction, speed of sound, and bulk velocity. The data is provided to a model that calculates the multiphase flow rates. The sensors are comprised of various combinations of temperature and pressure sensors combined with speed of sound and/or bulk velocity sensors and are distributed at various axial positions along an oil production pipe. In one embodiment the sensors comprise Bragg grating based optical sensors.

Claims

1. A sensing system for measuring a fluid mixture in a pipe, comprising:

a first temperature sensor for providing a first temperature signal indicative of the temperature of the fluid mixture;

a first pressure sensor for providing a first pressure signal indicative of the pressure of the fluid mixture;

a velocity sensor for providing a velocity signal indicative of the velocity of the fluid mixture, wherein the velocity sensor passively senses pressure disturbances occurring within the fluid mixture without detecting acoustical energy added to the fluid mixture by the sensing system;

a sound speed sensor for providing a sound speed signal indicative of the fluid sound speed in the fluid mixture, wherein the sound speed sensor passively senses pressure disturbances occurring within the fluid mixture without detecting acoustical energy added to the fluid mixture by the sensing system; and

a logic system for receiving the first temperature signal, the first pressure signal, the velocity signal, and the sound speed signal.

2. The sensing system of claim 1, wherein the first temperature sensor, the first pressure sensor, the velocity sensor, and the sound speed sensor are located at a first axial location along the pipe.

3. The sensing system of claim 2 further comprising a second pressure sensor at a second axial location along the pipe for providing a second pressure signal that is received by the logic system.

4. The sensing system of claim 2 further comprising a second temperature sensor at a second axial location along the pipe for providing a second temperature signal that is received by the logic system.

5. The sensing system of claim 2 further comprising a second pressure sensor and a second temperature sensor at a second axial location along the pipe for providing a second pressure signal and a second temperature signal that are received by the logic system.

6. The sensing system of claim 1, wherein the first temperature sensor and the first pressure sensor are located at a first axial location along the pipe and the velocity sensor and the sound speed sensor are located at a second axial location along the pipe.

7. The sensing system of claim 6 further comprising a second pressure sensor at a third axial location along the pipe for providing a second pressure signal that is received by the logic system.

8. The sensing system of claim 6 further comprising a second temperature sensor at a third axial location along the pipe for providing a second temperature signal that is received by the logic system.

9. The sensing system of claim 6 further comprising a second pressure sensor and a second temperature sensor at a third axial location along the pipe for providing a second pressure signal and a second temperature signal that are received by the logic system.

10. The sensing system of claim 1, wherein the first temperature sensor comprises a Bragg grating formed in an optical fiber.

11. The sensing system of claim 1, wherein the first pressure sensor comprises a Bragg grating formed in an optical fiber.

12. The sensing system of claim 1, wherein the velocity sensor comprises a plurality of fiber optic pressure sensors.

13. The sensing system of claim 12, wherein the plurality of pressure sensors comprise a series of wraps around the pipe.

14. The sensing system of claim 13, wherein the wraps in the series are separated by Bragg gratings.

15. The sensing system of claim 1, wherein the sound speed sensor comprises a plurality of fiber optic pressure sensors.

16. The sensing system of claim 15, wherein the plurality of pressure sensors comprise a series of wraps around the pipe.

17. The sensing system of claim 16, wherein the wraps in the series are separated by Bragg gratings.

18. The sensing system of claim 1, wherein the sound speed sensor provides sound speed signals below 20 kHz.

19. A method for measuring a fluid mixture in a pipe with a sensing system, comprising:

measuring a temperature of the fluid mixture and providing a first temperature signal indicative of the measured temperature using a first temperature sensor along the pipe;

measuring a pressure of the fluid mixture and providing a first pressure signal indicative of the measured pressure using a first pressure sensor along the pipe;

using a velocity sensor along the pipe to passively measure pressure disturbances indicative of a velocity of the fluid mixture without detecting acoustical energy added to the fluid mixture by the sensing system and providing a signal indicative of the measured velocity;

using a sound speed sensor along the pipe to passively measure pressure disturbances indicative of a sound speed of the fluid mixture without detecting acoustical energy added to the fluid mixture by the sensing system and providing a signal indicative of the measured sound speed; and

receiving the first temperature signal, first pressure signal, velocity signal and sound speed signal for use by a logic system.

20. The method of claim 19, wherein the first temperature sensor, the first pressure sensor, the velocity sensor, and the sound speed sensor are located at a first axial location along the pipe.

21. The method of claim 20 further comprising measuring a pressure of the fluid mixture and providing a second pressure signal indicative of the measured pressure that is received by the logic system using a second pressure sensor at a second axial location along the pipe.

22. The method of claim 20 further comprising measuring a temperature of the fluid mixture and providing a second temperature signal indicative of the measured temperature that is received by the logic system using a second temperature sensor at a second axial location along the pipe.

23. The method of claim 19, wherein the first temperature sensor and the first pressure sensor are located at a first axial location along the pipe and the velocity sensor and the sound speed sensor are located at a second axial location along the pipe.

24. The method of claim 23 further comprising measuring a pressure of the fluid mixture and providing a second pressure signal indicative of the measured pressure that is received by the logic system using a second pressure sensor at a third axial location along the pipe.

25. The method of claim 23 further comprising measuring a temperature of the fluid mixture and providing a second temperature signal indicative of the measured temperature that is received by the logic system using a second temperature sensor at a third axial location along the pipe.

26. The method of claim 19, wherein the first temperature sensor comprises a Bragg grating formed in an optical fiber.

27. The method of claim 19, wherein the first pressure sensor comprises a Bragg grating formed in an optical fiber.

28. The method of claim 19, wherein the velocity sensor comprises a plurality of fiber optic pressure sensors.

29. The method of claim 28, wherein the plurality of pressure sensors comprise a series of wraps around the pipe.

30. The method of claim 29, wherein the wraps in the series are separated by Bragg gratings.

31. The method of claim 19, wherein the sound speed sensor comprises a plurality of fiber optic pressure sensors.

32. The method of claim 31, wherein the plurality of pressure sensors comprise a series of wraps around the pipe.

33. The method of claim 32, wherein the wraps in the series are separated by Bragg gratings.

34. The method of claim 19, wherein the sound speed sensor provides a sound speed signal below 20 kHz.