Wet Gas Measurement

• US 20080053240A1
• Filed: 08/28/2007
• Published: 03/06/2008
• Est. Priority Date: 08/28/2006
• Status: Active Grant

• Current Assignee: Schneider Electric Systems USA, Inc. (Schneider Electric SE)
• Original Assignee: Invensys Systems Incorporated (Invensys PLC)
• Inventors: Tombs, Michael, Henry, Manus
• Granted Patent: US 7,617,055 B2
• Time in Patent Office: Days
• 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
• CPC Class Codes: G01F 1/8409 constructional details
• CPC Class Codes: G01F 1/8431 electronic circuits
• CPC Class Codes: G01F 1/8436 signal processing
• CPC Class Codes: G01F 1/8481 having loop-shaped measuring conduits, e.g. the measuring conduits form a loop with a crossing point
• CPC Class Codes: G01F 1/8486 with multiple measuring conduits
• CPC Class Codes: G01F 15/024 involving digital counting
• CPC Class Codes: G01F 25/10 of flowmeters
• CPC Class Codes: G01N 9/002 using variation of the resonant frequency of an element vibrating in contact with the material submitted to analysis G01N9/34 takes precedence

Abstract

A multi-phase process fluid is passed through a vibratable flowtube. Motion is induced in the vibratable flowtube. A first apparent property of the multi-phase process fluid based on the motion of the vibratable flowtube is determined, and an apparent intermediate value associated with the multi-phase process fluid based on the first apparent property is determined. A corrected intermediate value is determined based on a mapping between the intermediate value and the corrected intermediate value. A phase-specific property of a phase of the multi-phase process fluid is determined based on the corrected intermediate value.

Claims

1. A method comprising:

passing a multi-phase process fluid through a vibratable flowtube;

inducing motion in the vibratable flowtube;

determining a first apparent property of the multi-phase process fluid based on the motion of the vibratable flowtube;

determining an apparent intermediate value associated with the multi-phase process fluid based on the first apparent property;

determining a corrected intermediate value based on a mapping between the apparent intermediate value and the corrected intermediate value; and

determining a phase-specific property of a phase of the multi-phase process fluid based on the corrected intermediate value.

2. The method of claim 1, wherein the mapping is a neural network.

3. The method of claim 2, further comprising:

determining that the apparent intermediate value is within a first defined region of values prior to determining the corrected intermediate value; and

determining that the corrected intermediate value is within a second defined region of values prior to determining the phase-specific property of a phase of the multi-phase process fluid.

4. The method of claim 1, wherein the multi-phase process fluid is a wet gas.

5. The method of claim 4, wherein

the multi-phase process fluid includes a first phase and a second phase,

the first phase includes a non-gas fluid, and

the second phase includes a gas.

6. The method of claim 4, wherein the multi-phase process fluid includes

a first phase including a first non-gas fluid, and

a second phase including a second non-gas fluid, and

a third phase including a gas.

7. The method of claim 1, wherein determining the first apparent property of the multi-phase process fluid includes determining a second apparent property of the multi-phase process fluid.

8. The method of claim 7, wherein the first apparent property of the multiphase process fluid is a mass flow rate and the second apparent property is a density.

9. The method of claim 1 further comprising receiving one or more measurements corresponding to an additional property of the process fluid.

10. The method of claim 9 wherein

the additional property of the multi-phase fluid includes one or more of a temperature of the multi-phase fluid, a pressure associated with the multi-phase fluid, and a watercut of the multi-phase fluid;

and

determining an apparent intermediate value associated with the multi-phase process fluid based on the first apparent property includes determining the intermediate value based on the first apparent property and the additional property.

11. The method of claim 1, wherein determining an apparent intermediate value associated with the multi-phase process fluid based on the first apparent property includes determining a volume fraction associated with an amount of non-gas fluid in the multi-phase process fluid and a volumetric flow rate of the multi-phase fluid.

12. The method of claim 1, wherein determining an apparent intermediate value associated with the multi-phase process fluid based on the first apparent property includes determining a first Froude number corresponding to a non-gas phase of the multi-phase fluid and a second Froude number corresponding to a gas phase of the multi-phase fluid.

13. The method of claim 1, wherein determining a phase-specific property of a phase of the multi-phase process fluid based on the corrected intermediate value includes determining a mass flow rate of a non-gas phase of the multi-phase fluid.

14. A flowmeter comprising:

a vibratable flowtube, the flowtube containing a multi-phase fluid;

a driver connected to the flowtube and configured to impart motion to the flowtube such that the flowtube vibrates;

a sensor connected to the flowtube and configured to sense the motion of the flowtube and generate a sensor signal; and

a controller to receive the sensor signal and configured to;

determine a first apparent property of the multi-phase process fluid based on the motion of the vibratable flowtube;

determine an apparent intermediate value associated with the multi-phase process fluid based on the first apparent property;

determine a corrected intermediate value based on a mapping between the apparent intermediate value and the corrected intermediate value; and

determine a phase-specific property of a phase of the multi-phase process fluid based on the corrected intermediate value.

15. The flowmeter of claim 14, wherein the mapping is a neural network configured to determine an error in the intermediate value resulting from the presence of the multi-flow process fluid.

16. The flowmeter of claim 14, wherein the controller is further configured to:

determine that the apparent intermediate value is within a first defined region of values prior to determining the corrected intermediate value; and

determine that the corrected intermediate value is within a second defined region of values prior to determining the phase-specific property of a phase of the multi-phase process fluid.

17. The flowmeter of claim 14, wherein the multi-phase process fluid is a wet gas.

18. The flowmeter of claim 14, wherein determining the first apparent property of the multi-phase process fluid includes determining a second apparent property of the multi-phase process fluid.

19. The flow meter of claim 14, wherein the first apparent property of the multiphase process fluid is a mass flow rate and the second apparent property is a density.

20. The flowmeter of claim 14 wherein the controller is further configured to receive one or more measurements corresponding to a second apparent property of the process fluid.

21. The flowmeter of claim 14, wherein determining an apparent intermediate value associated with the multi-phase process fluid based on the first apparent property includes determining a first Froude number corresponding to a non-gas phase of the multi-phase fluid and a second Froude number corresponding to a gas phase of the multi-phase fluid.

22. A flowmeter transmitter comprising:

at least one processing device; and

a storage device, the storage device storing instructions for causing the at least one processing device to;

determine a first apparent property of the multi-phase process fluid based on the motion of the vibratable flowtube;

determine an apparent intermediate value associated with the multi-phase process fluid based on the first apparent property;

determine a corrected intermediate value based on a mapping between the apparent intermediate value and the corrected intermediate value; and

determine a phase-specific property of a phase of the multi-phase process fluid based on the corrected intermediate value.

23. The transmitter of claim 22, wherein the multi-phase process fluid is a wet gas.

24. The transmitter of claim 22, wherein the storage device further stores instructions for causing the at least one processing device to receive one or more measurements corresponding to a second apparent property of the process fluid.

25. The transmitter of claim 22, wherein determining an apparent intermediate value associated with the multi-phase process fluid based on the first apparent property includes determining a first Froude number corresponding to a non-gas phase of the multi-phase fluid and a second Froude number corresponding to a gas phase of the multi-phase fluid.