Apparatus and method for providing a fluid cut measurement of a multi-liquid mixture compensated for entrained gas
View Patent ↗An apparatus for determining a fluid cut measurement of a multi-liquid mixture includes a first device configured to sense at least one parameter of the mixture to determine a fluid cut of a liquid in the mixture. A second device is configured to determine a concentration of gas in the mixture in response to a speed of sound in the mixture; and a signal processor is configured to adjust the fluid cut of the liquid using the concentration of the gas to determine a compensated fluid cut of the liquid. The parameter of the mixture sensed by the first device may include a density of the mixture (e.g., by way of a Coriolis meter), a permittivity of the mixture (e.g., by way of a resonant microwave oscillator), or an amount of microwave energy absorbed by the mixture (e.g., by way of a microwave absorption watercut meter). The signal processor may employ different correction factors depending on the type of fluid cut device used. The second device may include a gas volume fraction meter.
1. An apparatus for providing a corrected liquid phase fraction measurement of a first liquid component of a multi-liquid mixture, the multi-liquid mixture flowing through a pipe, and the corrected liquid phase fraction measurement being compensated for entrained gas flowing with the multi-liquid mixture through the pipe, the apparatus comprising:
a first meter that determines at least one parameter of the multi-liquid mixture, the parameter being indicative of an uncorrected liquid phase fraction of the first liquid component and provides a first output signal indicative of the uncorrected liquid phase fraction of the first liquid component;
a second meter that determines a phase fraction of the entrained gas and provides a second output signal indicative of the phase fraction of the entrained gas; and
a signal processor, responsive to the first and second output signals for providing the corrected liquid phase fraction measurement of the first liquid component by determining a compensated phase fraction of the first liquid component which is the uncorrected liquid phase fraction of the first liquid component compensated for the entrained gas.
2. The apparatus of claim 1 , wherein the multi-liquid mixture includes at least a second fluid component, the parameter sensed by the first meter includes a permittivity of the multi-liquid mixture, and the signal processor determines the corrected liquid phase fraction measurement using the equation:
Φ
compensated
=
Φ
liquid
1
-
ϕ
G
ɛ
liquid2
-
ɛ
G
ɛ
liquid2
-
ɛ
liquid1
where: Φ compensated is the corrected liquid phase fraction measurement of the first liquid component, Φ liquid 1 is the uncorrected phase fraction of the first liquid component provided by the first meter, Φ G is the phase fraction of the gas provided by the second meter, ε liquid1 is a permittivity of the first liquid component, ε liquid2 is a permittivity of the at the least second liquid component, and ε G is a permittivity of the gas.
3. The apparatus of claim 1 , wherein the first meter includes a resonant microwave oscillator.
4. The apparatus of claim 1 , wherein the multi-liquid mixture includes oil and water and the first liquid component is selected from one of oil and water.
5. The apparatus of claim 1 , wherein the second meter includes at least two sensors at different axial locations along a pipe through which the mixture flows, each of the sensors providing a respective pressure signal indicative of a pressure disturbance within the pipe at a corresponding axial position, wherein the signal processor, responsive to the pressure signals, determines the speed of sound propagating though the mixture.
6. The apparatus of claim 1 , wherein the at least one parameter determined by the first meter includes the permittivity of the mixture.
7. The apparatus of claim 1 , wherein the first meter is a microwave fluid cut meter.
8. The apparatus of claim 1 , wherein the first meter is a microwave watercut meter.
9. The apparatus of claim 1 , wherein the second meter provides a signal indicative of the phase fraction of the gas in the mixture in response to a speed of sound propagating through the mixture.
10. The apparatus of claim 1 , wherein the second meter measures the speed of a one dimensional acoustic wave propagating axially through the mixture.
11. The apparatus of claim 1 , wherein the signal processor determines the phase fraction of the gas of the mixture in response to a speed of sound propagating through the mixture.
12. The apparatus of claim 1 , wherein the signal processor determines the phase fraction of a second liquid of the mixture, in response the first and second signals.
13. The apparatus of claim 1 , wherein the parameter sensed by the first device includes a density of the mixture, and the signal processor determines the compensated fluid cut using the equation:
Φ
compensated
=
Φ
liquid
1
-
ϕ
G
ρ
liquid
2
-
ρ
G
ρ
liquid
2
-
ρ
liquid
1
where: Φ compensated is the compensated fluid cut of the first liquid, Φ liquid1 is the of the first liquid provided by the first device, Φ G is the concentration of the gas provided by the second device, ρ liquid1 is a density of the first liquid, ρ liquid2 is a density of a second liquid in the mixture, and ρ G is a density of the gas.
14. The apparatus of claim 13 , wherein the first device includes at least one of a Coriolis meter and a gamma densitometer.
15. The apparatus of claim 1 , wherein the parameter sensed by the first device includes an amount of microwave energy absorbed by the mixture, and the signal processor determines the fluid cut using the equation:
Φ compensated =Φ liquid 1 −Φ G
where: Φ compensated is the compensated fluid cut of the first liquid, Φ liquid 1 is the fluid cut of the first liquid provided by the first device, and Φ G is the concentration of the gas.
16. The apparatus of claim 15 , wherein the fist device includes a microwave absorption watercut meter.
17. The apparatus of claim 1 , wherein the second meter includes at least two strain sensors disposed at different axial locations along the pipe, each of the strain sensors providing a respective strain signal indicative of acoustic pressure disturbances within the pipe at a corresponding axial position.
18. The apparatus of claim 17 , wherein the second meter determines the slope of an acoustic ridge in the k-ω plane to determine a speed of sound propagating through the mixture.
19. The apparatus of claim 17 , wherein the at least two sensors include 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 sensors.
20. A method for providing a corrected liquid phase fraction measurement of a first liquid component of a multi-liquid mixture, the multi-liquid mixture flowing through a pipe, and the corrected liquid phase fraction measurement beilng compensated for entrained gas flowing with the multi-liquid mixture through the pipe, the method comprising:
determining an uncorrected liquid fraction of the first liquid component in response to at least one first parameter of the mixture, and providing a first signal indicative of the uncorrected liquid phase fraction;
determining a phase fraction of the gas in the multi-liquid mixture, and providing a second signal indicative of the phase fraction of the gas; and
determining, in response to the first and second signals, the corrected liquid phase fraction measurement which is the uncorrected liquid phase fraction of the first liquid component compensated for the entrained gas.
21. The method of claim 20 , wherein the mixture includes oil and water and the first liquid component is selected from one of oil and water.
22. The method of claim 20 , wherein the speed of sound propagating through the mixture is determined using at least two strain sensors at different axial locations along the pipe through which the mixture flows, each of the strain sensors providing a respective pressure signal indicative of a pressure disturbance within the pipe at a corresponding axial position, and the speed of sound propagating through the mixture is detennined in response to the pressure signals.
23. The method of claim 20 , wherein the at least one parameter determined includes the permittivity of the mixture.
24. The method of claim 20 , wherein the determining of the at least one parameter is determined using a microwave fluid cut meter.
25. The method of claim 20 , wherein the determining of the at least one parameter is determined using a microwave watercut meter.
26. The method of claim 20 , further includes determining a slope of an acoustic ridge in the k-ω plane to determine a speed of sound propagating through the mixture.
27. The method of claim 20 , further includes measuring the speed of a one dimensional acoustic wave propagating axially through the mixture.
28. The method of claim 20 , further includes determining the phase fraction of a second liquid of the mixture, in response the first and second signals.
29. The method of claim 20 , wherein the at least one first parameter includes a density of the mixture, and the compensated fluid cut is determined using the equation:
Φ
compensated
=
Φ
liquid
1
-
ϕ
G
ρ
liquid2
-
ρ
G
ρ
liquid2
-
ρ
liquid1
where: Φ compensated is the compensated fluid cut of the first liquid, Φ liquid1 is the fluid cut of the first liquid, Φ G is the concentration of the gas, ρ liquid1 is a density of the first liquid, ρ liquid2 is a density of a second liquid in the mixture, and ρ G is a density of the gas.
30. The method of claim 29 , wherein the density of the mixture is determined using one of a Coriolis meter and a gamma densitometer.
31. The method of claim 20 , wherein the multi-liquid mixture includes at least a second fluid component, the at least one first parameter includes a permittivity of the mixture, and the corrected liquid phase fraction measurement of the first liquid component is determined using the equation:
Φ
compensated
=
Φ
liquid
1
-
ϕ
G
ɛ
liquid2
-
ɛ
G
ɛ
liquid2
-
ɛ
liquid1
where: Φ compensated is the corrected liquid phase fraction measurement of the first liquid component, Φ liquid 1 is the uncorrected liquid phase fraction of the first liquid component, Φ G is the phase fraction of the gas, ε liquid1 is a permittivity of the first liquid component, ε liquid2 is a permittivity of the at least second liquid component, and ε G is a permnittivity of the gas.
32. The method of claim 31 , wherein the permittivity of the mixture is determined using a resonant microwave oscillator.
33. The method of claim 20 , wherein the at least one first parameter includes an amount of microwave energy absorbed by the mixture, and the fluid cut is determined using the equation:
Φ compensated =Φ liquid 1 −Φ G
where: Φ compensated is the compensated fluid cut of the first liquid, Φ liquid 1 is the fluid cut of the first liquid, and Φ G is the concentration of the gas.
34. The method of claim 33 , wherein the amount of microwave energy absorbed by the mixture is determined using a microwave absorption watercut meter.
35. The a method of claim 20 , wherein determining the phase fraction of the gas includes using a second meter including at least two strain sensors disposed at different axial locations along the pipe, each of the strain sensors providing a respective strain signal indicative of acoustic pressure disturbances within the pipe at a corresponding axial position.
36. The method of claim 35 , wherein the at least two sensors include 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 sensors.