US3913398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for determining fluid flow rates from temperature log data
Assignee: Hughes Tool Co
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Filing: 1973-10-09
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Granted: 1975-10-21
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Expires: 1993-10-09
Abstract
Abstract An illustrative embodiment of the present invention includes methods and apparatus for producing measurements in a fluid flowing in a subsurface well or pipe which are representative of temperature changes attributed to heat transfer between the flowing fluid and heat conductive media surrounding the flow path. Measured temperatures are compared with temperatures computed from a model for heat transfer representative of the conditions known to be present but which also must incorporate estimates of at least one unknown parameter. The model is progressively adjusted using a series of estimates for at least one unknown parameter until a satisfactory comparison is obtained between measured and computed temperatures. From the resulting final estimate, mass flow rates and, in some cases, volumetric flow rates are then computed. Optional output includes measured temperatures along with temperatures computed using the adjusted model for heat transfer and the final estimate. The method is particularly applicable to determining flow rates of fluids produced in oil wells at each of several possible entry points, especially where these entry points are spaced so closely that a constant rate of heat transfer is not reached between these points. This latter condition is indicated when the temperature of the flowing fluid does not reach an asymptotic value.
Inventors
- 👤 M Rex Curtis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:58
CPC Classifications
E; E21; E21B; E21B47/00; E21B47/06; E21B47/07; E21B47/10; E21B47/103
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
78 words
A method of automatically determining flow characteristics of fluids entering a substance flow path comprising: producing measurements representative of the temperature of a fluid flowing in a subsurface flow path surrounded by a subsurface heat conductive media; adjusting a given model for heat transfer between said subsurface heat conductive media and said flowing fluid to fit at least a portion of said measurements; and determining at least one flow rate characteristic of said fluid using said adjusted model.
Claim 2
Independent Claim
78 words
A method of automatically determining flow characteristics of fluids entering a substance flow path comprising: producing measurements representative of the temperature of a fluid flowing in a subsurface flow path surrounded by a subsurface heat conductive media; adjusting a given model for heat transfer between said subsurface heat conductive media and said flowing fluid to fit at least a portion of said measurements; and determining at least one flow rate characteristic of said fluid using said adjusted model.
Claim 3
Dependent Claim
43 words
The method of claim 1 wherein said flowing fluid is at a temperature different than the equilibrium temperature of said subsurface heat conductive media over at least a portion of said measurements causing a radial heat transfer between said media and said fluid.
Claim 4
Dependent Claim
19 words
The method of claim 2 wherein said determined flow rate characteristic of said fluid is the mass flow rate.
Claim 5
Dependent Claim
19 words
The method of claim 2 wherein said determined flow rate characteristic of said fluids is the volumetric flow rate.
Claim 6
Dependent Claim
44 words
The method of claim 3 wherein said portion of said measurements representative of temperature are made at a point where the difference in temperature between said flowing fluid and the equilibrium temperature of said subsurface heat conductive media has not reached an equilibrium condition.
Claim 7
Dependent Claim
23 words
The method of claim 5 wherein said equilibrium temperature of said subsurface heat conductive media is included in said model for heat transfer.
Claim 8
Dependent Claim
24 words
The method of claim 6 wherein said model for heat transfer includes a relaxation parameter from which a mass flow rate may be determined.
Claim 9
Dependent Claim
21 words
The method of claim 7 wherein said relaxation parameter has a non-linear relationship with at least a portion of said measurements.
Claim 10
Dependent Claim
13 words
The method of claim 8 wherein said non-linear relationship includes an exponential function.
Claim 11
Dependent Claim
52 words
The method of claim 9 wherein said step of adjusting said model for heat transfer includes the step of approximating said relaxation parameter and computing from said approximation and said model a temperature comparable to the temperature of said flowing fluid at a point corresponding to at least one of said measurements.
Claim 12
Dependent Claim
41 words
The method of claim 10 wherein saiD step of adjusting said model includes the step of comparing at least one of said measurements representative of the temperature of the flowing fluid with the temperature computed from said model using said approximation.
Claim 13
Dependent Claim
29 words
The method of claim 11 wherein said step of adjusting said model includes the step of improving said approximation based upon said comparison of said computed and measured temperatures.
Claim 14
Dependent Claim
37 words
The method of claim 12 wherein said step of improving said approximation includes adjusting successive approximations of said relaxation parameter included in said model to reduce differences between said computed and measured temperatures to a satisfactory level.
Claim 15
Dependent Claim
52 words
The method of claim 13 wherein the source for said fluid is a subsurface earth formation and said fluid is produced from said formation at temperatures substantially equal to said formation temperature and flows in the subsurface flow path over a portion thereof which is different in temperature than said produced fluid.
Claim 16
Dependent Claim
30 words
The method of claim 14 wherein said measurements representative of temperature are representative of temperature changes occurring in said flowing fluid at a multiplicity of points along the flow path.
Claim 17
Dependent Claim
39 words
The method of claim 15 wherein said measurements are made at substantially the same time and said time is known in reference to a time for beginning production of said fluid and included in said model for heat transfer.
Claim 18
Dependent Claim
105 words
The method of claim 16 wherein the step of adjusting said model by improving the approximation of said relaxation parameter to reduce differences between computed and measured temperatures includes repeating said step of adjusting for at least a portion of said measurements representative of temperature at more than one point along the flow path to derive approximated relaxation parameters for these points and combining said approximated parameters to determine a representative relaxation parameter for at least a portion of said measurements, said representative relaxation parameter being functionally related to the mass flow rate of the fluid flowing in the subsurface flow path at said points.
Claim 19
Dependent Claim
35 words
The method of claim 14 wherein said measurements representative of temperature are representative of temperature changes occurring at various times in said flowing fluid at the same point along the flow path of said fluid.
Claim 20
Dependent Claim
21 words
The method of claim 18 wherein said various times are known in reference to the time production began of said fluid.
Claim 21
Independent Claim
91 words
A method of automatically determining the mass flow rate of a fluid produced in a subsurface well comprising: producing measurements representative of the temperature of a fluid flowing in a borehole at points with a known relationship to at least one possible entry point for said fluid; adjusting a given model for heat transfer between said flowing fluid and a subsurface heat conductive media surrounding said flowing fluid to substantially compare with at least a portion of said measurements; and determining a characteristic representative of the flow rate of said fluid.
Claim 22
Independent Claim
91 words
A method of automatically determining the mass flow rate of a fluid produced in a subsurface well comprising: producing measurements representative of the temperature of a fluid flowing in a borehole at points with a known relationship to at least one possible entry point for said fluid; adjusting a given model for heat transfer between said flowing fluid and a subsurface heat conductive media surrounding said flowing fluid to substantially compare with at least a portion of said measurements; and determining a characteristic representative of the flow rate of said fluid.
Claim 23
Dependent Claim
36 words
The method of claim 20 wherein said heat transfer is assumed to be in directions radial to the direction of fluid flow and induced by a known temperature difference between said fluid and said surrounding media.
Claim 24
Dependent Claim
19 words
The method of claim 21 wherein said temperature difference and induced heat transfer are not in an equilibrium condition.
Claim 25
Dependent Claim
20 words
The method of claim 22 wherein said model includes an unknown parameter which is a function of the flow rate.
Claim 26
Dependent Claim
15 words
The method of claim 23 wherein said parameter has a non-linear relationship with said measurements.
Claim 27
Dependent Claim
20 words
The method of claim 24 wherein said step of adjusting said model includes the step of approximating said unknown parameter.
Claim 28
Dependent Claim
42 words
The method of claim 25 wherein said step of approximating said unknown parameter includes the step of improving the approximation of said unknown parameter based upon a comparison of said measurements and Corresponding temperatures computed from said model including said unknown parameter.
Claim 29
Dependent Claim
47 words
The method of claim 26 wherein said step of improving the approximation of said unknown parameter includes the step of increasing said approximation if said computed temperatures are too high and decreasing said approximation if said computed temperatures are too low when compared with the corresponding measurements.
Claim 30
Dependent Claim
26 words
The method of claim 27 wherein the step of determining a characteristic representative of the flow rate includes the step of determining the mass flow rate.
Claim 31
Dependent Claim
40 words
The method of claim 28 wherein said points with a known relationship to at least one possible entry point for said fluid correspond to depths of a known distance along the flow path of said fluid from said entry point.
Claim 32
Dependent Claim
14 words
The method claim 29 wherein said measurements are made at substantially the same time.
Claim 33
Dependent Claim
41 words
The method of claim 28 wherein said points with a known relationship to a least one possible entry point for said fluid correspond to times of a known duration from the start of entry of said fluid from said entry point.
Claim 34
Independent Claim
135 words
A method of automatically determining the flow rate of fluid produced from subsurface formations and flowing through a borehole surrounded by heat conductive media comprising: producing measurements representative of the temperature of the fluid as it flows through a portion of the borehole and experiences a non-linear rate of radial heat transfer with the surrounding heat conductive media; computing temperatures corresponding to the measurements from a given model for the radial heat transfer using an approximation of an unknown value of a parameter in the model which is a function of the mass flow rate of the flowing fluid; comparing the computed temperatures and corresponding measurements and adjusting the approximation to obtain a satisfactory comparison; and determining the flow rate of the flowing fluid from the adjusted approximation value of the parameter in the model.
Claim 35
Independent Claim
135 words
A method of automatically determining the flow rate of fluid produced from subsurface formations and flowing through a borehole surrounded by heat conductive media comprising: producing measurements representative of the temperature of the fluid as it flows through a portion of the borehole and experiences a non-linear rate of radial heat transfer with the surrounding heat conductive media; computing temperatures corresponding to the measurements from a given model for the radial heat transfer using an approximation of an unknown value of a parameter in the model which is a function of the mass flow rate of the flowing fluid; comparing the computed temperatures and corresponding measurements and adjusting the approximation to obtain a satisfactory comparison; and determining the flow rate of the flowing fluid from the adjusted approximation value of the parameter in the model.
Claim 36
Dependent Claim
25 words
The method of claim 32 and further including the step of outputing said computed temperatures in a manner which allows comparison with said corresponding measurements.
Claim 37
Independent Claim
153 words
An apparatus for automatically determining flow rates of fluids produced from subsurface formations and flowing through a borehole surrounded by heat conductive media, comprising: a borehole fluid temperature measuring means for producing measurements representative of the temperature of the fluid as it flows through a portion of the borehole and experiences a non-linear rate of radial heat transfer with the surrounding heat conductive media; means for computing temperatures corresponding to the measurements produced by the temperature measuring means, said computing means including means for providing a model for the radial heat transfer dependent upon a value of a parameter related to the flow rate of the fluid experiencing the heat transfer; means for approximating a parameter coupled to the computing means and operative to minimize differences between the produced and computed temperatures; and means coupled to the parameter approximating means for determining the flow rate of the fluid represented by the temperature measurements.
Claim 38
Independent Claim
153 words
An apparatus for automatically determining flow rates of fluids produced from subsurface formations and flowing through a borehole surrounded by heat conductive media, comprising: a borehole fluid temperature measuring means for producing measurements representative of the temperature of the fluid as it flows through a portion of the borehole and experiences a non-linear rate of radial heat transfer with the surrounding heat conductive media; means for computing temperatures corresponding to the measurements produced by the temperature measuring means, said computing means including means for providing a model for the radial heat transfer dependent upon a value of a parameter related to the flow rate of the fluid experiencing the heat transfer; means for approximating a parameter coupled to the computing means and operative to minimize differences between the produced and computed temperatures; and means coupled to the parameter approximating means for determining the flow rate of the fluid represented by the temperature measurements.
Claim 39
Dependent Claim
40 words
The apparatus of claim 34 and further including an output means coupled with the computing means and the measuring means to provide output of the temperatures respectively computed and produced from these means in a common presentation for visual comparison.
Claim 40
Independent Claim
159 words
A method of automatically determining with a machine the flow rate of a fluid produced from a subsurface formation and flowing through a subsurface flow path surrounded by heat conductive media comprising: producing measurements representative of the temperature of the flowing fluid at a plurality of points along a portion of the flow path undergoing a non-linear rate of radial heat transfer with the surrounding heat conductive media; computing teMperatures from a given model for the radial heat transfer using an approximation of an unknown value of a parameter which is a function of the mass flow rate of the flowing fluid, said computed temperatures corresponding to at least a segment of the measured temperatures; comparing said computed temperatures and corresponding measurements and adjusting according to said comparison the approximation of the unknown value to obtain a satisfactory comparison; and determining the flow rate of the flowing fluid from the adjusted approximation of the unknown value of the parameter.
Claim 41
Independent Claim
159 words
A method of automatically determining with a machine the flow rate of a fluid produced from a subsurface formation and flowing through a subsurface flow path surrounded by heat conductive media comprising: producing measurements representative of the temperature of the flowing fluid at a plurality of points along a portion of the flow path undergoing a non-linear rate of radial heat transfer with the surrounding heat conductive media; computing teMperatures from a given model for the radial heat transfer using an approximation of an unknown value of a parameter which is a function of the mass flow rate of the flowing fluid, said computed temperatures corresponding to at least a segment of the measured temperatures; comparing said computed temperatures and corresponding measurements and adjusting according to said comparison the approximation of the unknown value to obtain a satisfactory comparison; and determining the flow rate of the flowing fluid from the adjusted approximation of the unknown value of the parameter.
Claim 42
Dependent Claim
35 words
The method of claim 36 and further including the step of displaying said computed temperatures in a manner which allows further comparison with said corresponding measurements to allow confirmation that the model represents the measurements.
Claim 43
Independent Claim
150 words
A method of automatically determining with a machine the flow rate of a fluid produced from a subsurface formation and flowing through a subsurface borehole surrounded by heat conductive media comprising: producing measurements representative of the temperature of the flowing fluid at a plurality of points along a portion of the borehole undergoing a non-linear rate of radial heat transfer with the surrounding heat conductive media; computing temperatures from a given model for the radial heat transfer using an approximation of an unknown parameter which is a function of the mass flow rate of the flowing fluid, said computed temperatures corresponding to at least a portion of the measured temperatures; comparing said computed temperatures and corresponding measurements and adjusting according to said comparison the approximation of the unknown parameter to obtain a satisfactory comparison; and determining the flow rate of the flowing fluid from the adjusted approximation of the parameter.
Claim 44
Independent Claim
150 words
A method of automatically determining with a machine the flow rate of a fluid produced from a subsurface formation and flowing through a subsurface borehole surrounded by heat conductive media comprising: producing measurements representative of the temperature of the flowing fluid at a plurality of points along a portion of the borehole undergoing a non-linear rate of radial heat transfer with the surrounding heat conductive media; computing temperatures from a given model for the radial heat transfer using an approximation of an unknown parameter which is a function of the mass flow rate of the flowing fluid, said computed temperatures corresponding to at least a portion of the measured temperatures; comparing said computed temperatures and corresponding measurements and adjusting according to said comparison the approximation of the unknown parameter to obtain a satisfactory comparison; and determining the flow rate of the flowing fluid from the adjusted approximation of the parameter.
Claim 45
Dependent Claim
35 words
The method of claim 38 and further including the step of displaying said computed temperatures in a manner which allows further comparison with said corresponding measurements to allow confirmation that the model represents the measurements.
Claim 46
Independent Claim
170 words
An apparatus for automatically determining the flow rate of a fluid produced from subsurface formations and flowing through a flow path surrounded by heat conductive media comprising: means for obtaining measurements representative of the temperature of the flowing fluid at a plurality of points along a portion of the flow path undergoing a non-linear rate of radial heat transfer with the surrounding heat conductive media; means for computing temperatures from a given model for radial heat transfer and comparing said computed temperatures with corresponding measured temperatures; said model including an approximation of an unknown value of a parameter related to the mass flow rate of the flowing fluid; said computed temperatures corresponding to at least a portion of the measured temperatures; said comparing including adjusting said approximation according to the relationship between said computed and measured temperatures until they are in substantial agreement; and means for determining the flow rate of the flowing fluid from the adjusted approximation of the value of the parameter related to the mass flow rate.
Claim 47
Independent Claim
170 words
An apparatus for automatically determining the flow rate of a fluid produced from subsurface formations and flowing through a flow path surrounded by heat conductive media comprising: means for obtaining measurements representative of the temperature of the flowing fluid at a plurality of points along a portion of the flow path undergoing a non-linear rate of radial heat transfer with the surrounding heat conductive media; means for computing temperatures from a given model for radial heat transfer and comparing said computed temperatures with corresponding measured temperatures; said model including an approximation of an unknown value of a parameter related to the mass flow rate of the flowing fluid; said computed temperatures corresponding to at least a portion of the measured temperatures; said comparing including adjusting said approximation according to the relationship between said computed and measured temperatures until they are in substantial agreement; and means for determining the flow rate of the flowing fluid from the adjusted approximation of the value of the parameter related to the mass flow rate.
Claim 48
Dependent Claim
44 words
The apparatus of claim 40 and further including means for displaying the measured temperatures and said computed temperatures corresponding to the adjusted approximation in a manner that allows visual comparison for confirmation that the adjusted approximation included in the model represents the measured temperatures.
References Cited (Backward Citations)
US2739475A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |