Apparatus and method for providing a density measurement augmented for entrained gas

• US 20050061060A1
• Filed: 08/02/2004
• Published: 03/24/2005
• Est. Priority Date: 07/15/2003
• Status: Active Grant

• Current Assignee: Expro Meters, Inc. (Umbrellastream LP, Inc.)
• Original Assignee: Cidra Sarl (Nordic Cultural & Educational Foundation)
• Inventors: Gysling, Daniel L., Curry, Patrick, Loose, Douglas H., Banach, Thomas E.
• Granted Patent: US 7,134,320 B2
• Time in Patent Office: Days
• US Class Current: 73/32.A
• 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 1/8413 means for influencing the flowmeter's motional or vibrational behaviour, e.g., conduit support or fixing means, or conduit attachments
• CPC Class Codes: G01F 1/8477 with multiple measuring conduits
• CPC Class Codes: G01F 1/849 having straight measuring conduits
• CPC Class Codes: G01F 15/024 involving digital counting
• CPC Class Codes: G01F 25/10 of flowmeters
• CPC Class Codes: G01N 2291/02818 Density, viscosity
• 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 flow measuring system combines a density measuring device and a device for measuring the speed of sound (SOS) propagating through the fluid flow and/or for determining the gas volume fraction (GVF) of the flow. The GVF meter measures acoustic pressures propagating through the fluids to measure the speed of sound α_mix propagating through the fluid to calculate at least gas volume fraction of the fluid and/or SOS. In response to the measured density and gas volume fraction, a processing unit determines the density of non-gaseous component of an aerated fluid flow. For three phase fluid flows, the processing unit can determine the phase fraction of the non-gaseous components of the fluid flow. The gas volume fraction (GVF) meter may include a sensing device having a plurality of strain-based or pressure sensors spaced axially along the pipe for measuring the acoustic pressures propagating through the flow.

Claims

1. A flow measuring system for determining the density of a fluid flowing in a pipe, the measuring system comprising:

a density meter that provides a density signal indicative of the density of the fluid flowing in the pipe;

a flow measuring device that measures the speed of sound propagating through the fluid, the measuring device providing an SOS signal indicative of the speed of sound propagating through the fluid and/or a GVF signal indicative of the gas volume fraction of the fluid; and

a processing unit that determines the density of the non-gaseous component of the aerated fluid in response to the SOS signal and/or the GVF signal and the density signal.

2. The measuring system of claim 1, wherein the speed of sound measurement is used to determine a gas volumetric fraction (GVF) in the flow of the fluid.

3. The measuring system of claim 1, wherein the density meter includes one of a nuclear densitometer, a vibrating vane densitometer and a coriolis meter.

4. The measuring system of claim 1, wherein the flow measuring device comprises an array of sensors disposed axially along the pipe for measuring acoustic pressures in the fluid.

5. The measuring system of claim 4, wherein the array of sensors includes at least one of strain based sensors, pressure sensors, ported pressure sensors and ultra-sonic sensors.

6. The measuring system of claim 1, wherein the processor provides a signal indicative of the volumetric phase fraction of the non-gaseous components of the fluid, wherein the non-gaseous components comprise two components.

7. The measuring device of claim 6, wherein the non-gaseous components of the fluid consist of liquid/liquid components or liquid/solid components of the fluid.

8. A well head metering system for measuring density of non-gaseous components of a three phase fluid flowing in a pipe, the metering system comprising:

a density meter that provides a density signal indicative of the density of the fluid flowing in the pipe;

a flow measuring device that measures the speed of sound propagating through the fluid, the measuring device providing an SOS signal indicative of the speed of sound propagating through the fluid and/or a GVF signal indicative of the gas volume fraction of the fluid; and

a processing unit that determines the density of the non-gaseous component of the aerated fluid in response to the SOS signal and/or the GVF signal and the density signal.

9. The measuring system of claim 8, wherein the speed of sound measurement is used to determine a gas volumetric fraction (GVF) in the flow of the fluid.

10. The measuring system of claim 8, wherein the density meter includes one of a nuclear densitometer, a vibrating vane densitometer and a coriolis meter.

11. The measuring system of claim 8, wherein the flow measuring device comprises an array of sensors disposed axially along the pipe for measuring acoustic pressures in the fluid.

12. The measuring system of claim 11, wherein the array of sensors includes at least one of strain based sensors, pressure sensors, ported pressure sensors and ultra-sonic sensors.

13. The measuring system of claim 8, wherein the processor provides a signal indicative of the volumetric phase fraction of the non-gaseous components of the fluid, wherein the non-gaseous components comprise two components.

14. The measuring device of claim 13, wherein the non-gaseous components of the fluid consist of liquid/liquid components or liquid/solid components of the fluid.

15. The measuring device of claim 8, further comprising an air separating device the separates a substantial portion of the air from aerated fluid.

16. The measuring device of claim 15, wherein the air separating device is a gas/liquid cylindrical cyclone (GLCC).