US4433573A
Expired / Lapsed
US
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Method and apparatus for determining the flow characteristics of a fluid in a well
Assignee: Schlumberger Technology Corp
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Filing: 1982-06-23
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Granted: 1984-02-28
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Expires: 2002-06-23
Abstract
Abstract The method according to the present invention for determining the flowrate of a fluid flowing in a well comprises the steps of lowering in the well a logging sonde comprising at least one vortex street generating obstacle and a transducer responsive to pressure variations due to the generation of vortices, the transducer producing, for each depth in the well, a detection signal the useful component of which has a frequency f and an amplitude A, deriving from the detection signal a first signal indicative of frequency f, deriving from the detection signal a second signal indicative of the reduced amplitude Ar, defined as the ratio A/f 2 , and forming from the first and second signals an indication of the flowrate in accordance with a first predetermined relationship expressing the frequency f as a function of the flowrate and of the bubble rate of the fluid at the respective depth, the first relationship including a linear dependency of the frequency f upon the flowrate, and a second predetermined relationship expressing the reduced amplitude Ar as a function of the bubble rate and of the flowrate.
Inventors
- 👤 Jean-Pierre Hulin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:25
CPC Classifications
E; E21; E21B; E21B47/00; E21B47/10; G; G01; G01F; G01F1/00; G01F1/05; G01F1/20; G01F1/32; G01F1/3209; G01F1/325; G01F1/3259; G01F1/3287
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
180 words
A method for determining the flowrate of a fluid flowing in a well, comprising the steps of: lowering in the well a logging sonde comprising at least one vortex street generating obstacle and a transducer responsive to pressure variations due to the generation of vortices, the transducer producing, for each depth in the well, a detection signal the useful component of which has a frequency f and an amplitude A, deriving from the detection signal a first signal indicative of frequency f, deriving from the detection signal a second signal indicative of the reduced amplitude Ar, defined as the ratio A/f 2 , and forming from the first and second signals an indication of the flowrate in accordance with a first predetermined relationship expressing the frequency f as a function of the flowrate and of the bubble rate of the fluid at the respective depth, the first relationship including a linear dependency of the frequency f upon the flowrate, and a second predetermined relationship expressing the reduced amplitude Ar as a function of the bubble rate and of the flowrate.
Claim 2
Independent Claim
180 words
A method for determining the flowrate of a fluid flowing in a well, comprising the steps of: lowering in the well a logging sonde comprising at least one vortex street generating obstacle and a transducer responsive to pressure variations due to the generation of vortices, the transducer producing, for each depth in the well, a detection signal the useful component of which has a frequency f and an amplitude A, deriving from the detection signal a first signal indicative of frequency f, deriving from the detection signal a second signal indicative of the reduced amplitude Ar, defined as the ratio A/f 2 , and forming from the first and second signals an indication of the flowrate in accordance with a first predetermined relationship expressing the frequency f as a function of the flowrate and of the bubble rate of the fluid at the respective depth, the first relationship including a linear dependency of the frequency f upon the flowrate, and a second predetermined relationship expressing the reduced amplitude Ar as a function of the bubble rate and of the flowrate.
Claim 3
Dependent Claim
31 words
The method of claim 1, wherein the second relationship defines the reduced amplitude as the product of a function of the bubble rate by a correction term dependent on the flowrate.
Claim 4
Dependent Claim
86 words
The method of claim 2, wherein the step of forming an indication of the flowrate is an iterative process comprising the steps of: deriving from the frequency, in accordance with the first relationship, a starting flowrate value corresponding to a null starting value of the bubble rate, deriving a bubble rate estimate from the reduced amplitude and the starting flowrate value in accordance with the second relationship, and deriving a flowrate estimate from the frequency and the bubble rate estimate in accordance with the first relationship.
Claim 5
Dependent Claim
14 words
The method of claim 3, wherein the iterative process is continued until it converges.
Claim 6
Dependent Claim
47 words
The method of claim 1, wherein the derivation of the second signal comprises the steps of: integrating the detection signal, deriving a signal indicative of the amplitude of the signal thus integrated, and forming the ratio of the signal to the first signal indicative of frequency f.
Claim 7
Independent Claim
207 words
A method for determining the flowrate of a fluid flowing in a well, comprising the steps of: lowering in the well a logging sonde comprising at least one vortex street generating obstacle and a transducer responsive to pressure variations due to the generation of vortices, the transducer producing, for each depth in the well, a detection signal the useful component of which has a frequency f and an amplitude A, producing a signal indicative of the density of the fluid at the respective depth, deriving from the detection signal a first signal indicative of frequency f, deriving from the detection signal a second signal indicative of the reduced amplitude Ar, defined as the ratio A/f 2 , forming a third signal indicative of the ratio of the reduced amplitude to the density, and forming from the first and third signals an indication of the flowrate in accordance with a first predetermined relationship expressing the frequency f as a function of the flowrate and of the bubble rate of the fluid at the respective depth, the first relationship including a linear dependency of the frequency f upon the flowrate, and a third predetermined relationship expressing the ratio as a function of the bubble rate and of the flowrate.
Claim 8
Independent Claim
207 words
A method for determining the flowrate of a fluid flowing in a well, comprising the steps of: lowering in the well a logging sonde comprising at least one vortex street generating obstacle and a transducer responsive to pressure variations due to the generation of vortices, the transducer producing, for each depth in the well, a detection signal the useful component of which has a frequency f and an amplitude A, producing a signal indicative of the density of the fluid at the respective depth, deriving from the detection signal a first signal indicative of frequency f, deriving from the detection signal a second signal indicative of the reduced amplitude Ar, defined as the ratio A/f 2 , forming a third signal indicative of the ratio of the reduced amplitude to the density, and forming from the first and third signals an indication of the flowrate in accordance with a first predetermined relationship expressing the frequency f as a function of the flowrate and of the bubble rate of the fluid at the respective depth, the first relationship including a linear dependency of the frequency f upon the flowrate, and a third predetermined relationship expressing the ratio as a function of the bubble rate and of the flowrate.
Claim 9
Independent Claim
176 words
A method for determining the bubble rate in the fluid flowing in a well from a detection signal related to a given depth in the well and produced by a flowmeter logging sonde comprising at least one vortex street generating obstacle and a transducer responsive to pressure variations due to the generation of vortices by the obstacle, the useful component of the signal having a frequency f and an amplitude A, comprising the steps of: deriving from the detection signal a first signal indicative of frequency f, deriving from the detection signal a second signal indicative of the reduced amplitude Ar, defined as the ratio A/f 2 , and forming from the first and second signals an indication of the bubble rate in accordance with a first predetermined relationship expressing the frequency f as a function of the flowrate and the bubble rate, the first relationship including a linear dependency of the frequency f upon the flowrate, and a second predetermined relationship expressing the reduced amplitude Ar in terms of the bubble rate and the flowrate.
Claim 10
Independent Claim
176 words
A method for determining the bubble rate in the fluid flowing in a well from a detection signal related to a given depth in the well and produced by a flowmeter logging sonde comprising at least one vortex street generating obstacle and a transducer responsive to pressure variations due to the generation of vortices by the obstacle, the useful component of the signal having a frequency f and an amplitude A, comprising the steps of: deriving from the detection signal a first signal indicative of frequency f, deriving from the detection signal a second signal indicative of the reduced amplitude Ar, defined as the ratio A/f 2 , and forming from the first and second signals an indication of the bubble rate in accordance with a first predetermined relationship expressing the frequency f as a function of the flowrate and the bubble rate, the first relationship including a linear dependency of the frequency f upon the flowrate, and a second predetermined relationship expressing the reduced amplitude Ar in terms of the bubble rate and the flowrate.
Claim 11
Dependent Claim
60 words
The method of claim 7, wherein a bubble rate estimate is formed by: deriving from the frequency f in accordance with the first relationship a starting flow rate value corresponding to a null starting value of the bubble rate, and deriving a bubble rate estimate from the reduced amplitude and the starting flowrate value in accordance with the second relationship.
Claim 12
Independent Claim
219 words
An apparatus for determining the flowrate of the fluid flowing in a well, comrising a flowmeter sonde adapted for movement through the well and including at least one vortex street generating obstacle and a transducer responsive to pressure variations due to the generation of vortices by said obstacle, said transducer producing, for each depth in the well, a detection signal the useful component of which has a frequency f linearly related to the flowrate and an amplitude A, a transmission cable from which the sonde is suspended, and signal processing means connected to the cable for deriving the flowrate from said detection signal, said signal processing means including means for deriving from said detection signal a first signal indicative of said frequency f and a second signal indicative of the reduced amplitude Ar, defined as the ratio A/f 2 , and means for deriving from said first and second signals an indication of the flowrate in accordance with a first predetermined relationship expressing the frequency f as a function of the flowrate and of the bubble rate of the fluid at the respective depth, said first relationship including a linear dependency of the frequency f upon the flowrate, and a second predetermined relationship expressing the reduced amplitude Ar as a function of the bubble rate and of the flowrate.
Claim 13
Independent Claim
219 words
An apparatus for determining the flowrate of the fluid flowing in a well, comrising a flowmeter sonde adapted for movement through the well and including at least one vortex street generating obstacle and a transducer responsive to pressure variations due to the generation of vortices by said obstacle, said transducer producing, for each depth in the well, a detection signal the useful component of which has a frequency f linearly related to the flowrate and an amplitude A, a transmission cable from which the sonde is suspended, and signal processing means connected to the cable for deriving the flowrate from said detection signal, said signal processing means including means for deriving from said detection signal a first signal indicative of said frequency f and a second signal indicative of the reduced amplitude Ar, defined as the ratio A/f 2 , and means for deriving from said first and second signals an indication of the flowrate in accordance with a first predetermined relationship expressing the frequency f as a function of the flowrate and of the bubble rate of the fluid at the respective depth, said first relationship including a linear dependency of the frequency f upon the flowrate, and a second predetermined relationship expressing the reduced amplitude Ar as a function of the bubble rate and of the flowrate.
References Cited (Backward Citations)
US3954006A
Cited
US4169376A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-27 | 1987-08-29 | 1988-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-27 | 1991-08-29 | 1992-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-27 | 1995-08-29 | 1996-02-28 | $7700.00 | Window Closed / Lapsed |