CN104389581B - Underground fluid induction device and fluid flow velocity measuring system using same - Google Patents

Underground fluid induction device and fluid flow velocity measuring system using same Download PDF

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Publication number
CN104389581B
CN104389581B CN201410475281.6A CN201410475281A CN104389581B CN 104389581 B CN104389581 B CN 104389581B CN 201410475281 A CN201410475281 A CN 201410475281A CN 104389581 B CN104389581 B CN 104389581B
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China
Prior art keywords
fluid
grating
venturi
piston
flow
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CN201410475281.6A
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CN104389581A (en
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陈少华
王伟
赵昆
孟倩
孙世宁
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China University of Petroleum Beijing CUPB
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China University of Petroleum Beijing CUPB
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    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B47/00Survey of boreholes or wells

Abstract

The invention provides an underground fluid induction device and a fluid flow velocity measuring system using the device. The underground fluid induction device comprises a pressure guide pipe, a spacing plate, a first piston, a first spring and a first grating arranged at the left side of the spacing plate, a second piston, a second spring and a second grating symmetrically arranged at the right side of the spacing plate, and a venturi pipe. The device uses the gratings for sensing the pressure applied to the pipe wall by the flowing of a fluid in the venturi pipe; and the flow velocity of the fluid in the pipe is obtained according to the characteristic of different flow velocity of the fluid and different pressure applied to the pipe wall. The device can realize precise fluid measurement under the conditions of limited space and severe environment of underground thousands of oil-gas wells.

Description

Downhole fluid induction installation and the fluid flow measuring systems using the device
Technical field
The present invention is, with regard to rate of flow of fluid monitoring technology, especially with regard to the rate of flow of fluid in petroleum industry field skill to be measured Art, is concretely a kind of downhole fluid induction installation and the fluid flow measuring systems using the device.
Background technology
Flow velocity/the flow of fluid is a weight in daily life, industrial processes, energy measurement and environment protection and monitoring Want parameter.At present conventional flow velocity/flow sensing is in respect of volumetric flowmeter, vortex-shedding meter, turbine flowmeter, electromagnetism flow velocity Instrument, ultrasonic current metre and acoustic Doppler velocimetry etc..The characteristics of these flow velocitys/flow sensing meter has respective and applicable model Enclose, have been obtained for being widely applied in daily life and industrial production, but these flow velocitys/flow sensing meter also has necessarily Limitation, such as volumetric flowmeter are bulky, are not suitable for high temperature low temperature situation, electromagnetic current metre and acoustic Doppler velocimetry Although certainty of measurement is higher, hold easy electromagnetic wave interference, and cost is also high.
Flow velocity/flow sensing meter key player for being played the part of during industrial and agricultural development is promoted, thus its from come out with Just to receive great attention.Nowadays with the fast development of modern industrial or agricultural, the upstream of some special dimensions, such as petroleum industry Exploration and development field is just extremely harsh for the requirement of rate of flow of fluid instrument, because the Oil/gas Well of a few kms in underground not only limited space And environmental condition very severe, because flow velocity/flow sensing meter volume conventional at present is big, easily limited to by electromagnetic interference Property, therefore at present conventional flow velocity/flow sensing meter cannot apply.
Therefore, a kind of new rate of flow of fluid measurement apparatus how are developed, it can adapt to the exploration of petroleum industry upstream and opens The field of sending out, realizes that accurate rate of flow of fluid is surveyed under the conditions of the confined space and high temperature, hyperbaric environment of the thousand of rice bran oil gas wells in underground Amount is this area technical problem urgently to be resolved hurrily.
The content of the invention
The technical problem to be solved in the present invention is to provide a kind of downhole fluid induction installation and the fluid stream using the device Fast measuring system, the pressure applied to tube wall when being flowed using grating sensing tube fluid, rate of flow of fluid is different, and tube wall is applied Pressure it is also different, and then tube fluid flow velocity is tried to achieve according to this pressure differential, solve current meter of the prior art easily by dry Disturb, volume is big, the problem that certainty of measurement is low.
In one embodiment of the present of invention, there is provided a kind of downhole fluid induction installation, wherein, the downhole fluid induction installation Including:Venturi tube, for guiding downhole fluid, the Venturi tube has an entrance and a venturi section, the entrance The diameter with diameter greater than the venturi section;Connecting pipe, is connected with the Venturi tube;Dividing plate, in being arranged at the connecting pipe The heart;First spring, is arranged at the dividing plate left side, and one end is connected with the dividing plate, and the other end is connected with a first piston, fluid First spring is acted on by the first piston in the pressure of the entrance;Second spring, is symmetricly set in described Dividing plate right side, one end is connected with the dividing plate, and the other end is connected with a second piston, and fluid passes through in the pressure of the venturi section The second piston acts on the second spring;First grating, one end is connected with the dividing plate, and the other end is lived with described first Plug connection, first grating is in all the time under the collective effect of first spring force and the entrance Fluid pressure Extended state, first grating receives an incident light, and reflects one first reflected light;And second grating, one end and institute Dividing plate connection is stated, the other end is connected with the second piston, and second grating is in the second spring elastic force and the venturi All the time it is in extended state under the collective effect of section Fluid pressure, second grating receives the incident light, and reflects one Second reflected light.
In another embodiment of the present invention, there is provided a kind of fluid flow measuring systems, wherein, the fluid flow measuring systems Including the downhole fluid induction installation in above-described embodiment, the fluid flow measuring systems also include LASER Light Source, grating demodulation Instrument and processing meanss, the LASER Light Source is connected with the downhole fluid induction installation, and the LASER Light Source is used to launch described Incident light;The grating demodulation instrument is connected with the downhole fluid induction installation, and the grating demodulation instrument is used to demodulate described the One reflected light obtains one first reflectance spectrum, and demodulates second reflected light and obtain one second reflectance spectrum;It is described to process dress Put and be connected with the grating demodulation instrument, the processing meanss are used for according to first reflectance spectrum and second reflectance spectrum Determine the rate of flow of fluid at the venturi tube inlet section.
The present invention provides a kind of downhole fluid induction installation and the fluid flow measuring systems using the device, by venturi Pipe and grating are organically combined, using the pressure applied to tube wall during flow of fluid in grating sensing Venturi tube, literary mound In tube fluid flow velocity it is different, the pressure that tube wall applies also is differed, fluid is eventually applied to light to the pressure that tube wall applies On grid, the power that grating is subject to is different, is also differed by the length of the reflectance spectrum peak wavelength of the laser of grating, so as to basis The length of reflectance spectrum peak wavelength draws this pressure differential, and stream in pipe is tried to achieve using Bernoulli equation further according to this pressure differential Rate of flow of fluid, the downhole fluid induction installation has simple structure, easy for installation, with low cost, electromagnetism interference, reliable operation, Certainty of measurement is high, takes up room little, the advantages of working under the adverse circumstances such as high temperature, high pressure, noise, deep-etching for a long time.
Description of the drawings
Fig. 1 is the structural representation of the downhole fluid induction installation of the present invention.
Fig. 2 is a preferred structure schematic diagram of downhole fluid induction installation of the present invention.
Fig. 3 is the structural representation of the Venturi tube of downhole fluid induction installation of the present invention.
Fig. 4 is the internal structure schematic diagram of the connecting pipe of downhole fluid induction installation of the present invention.
Fig. 5 is the structural representation of fluid flow measuring systems of the present invention.
Fig. 6 is the structural representation of the processing meanss of fluid flow measuring systems of the present invention.
Symbol description:
1 first grating
2 second gratings
3 first springs
4 second springs
5 first pistons
6 second pistons
7 dividing plates
8 first snap rings
9 second snap rings
10 upstream pilot interfaces
11 downstream pilot interfaces
12 Venturi tubes
13 connecting pipes
14 entrances
15 venturi sections
100 downhole fluid induction installations
200 LASER Light Sources
300 grating demodulation instrument
400 processing meanss
401 spectrum acquisition units
402 spectrum peak wavelength determining units
403 wavelength difference determining units
404 pressure differential determining units
405 rate of flow of fluid determining units
406 display units
Specific embodiment
Purpose, technical scheme and advantage to make the embodiment of the present invention becomes more apparent, below in conjunction with the accompanying drawings to this Bright embodiment is described in further details.Here, the schematic description and description of the present invention is used to explain the present invention, but and It is not as a limitation of the invention.
Fig. 1 is the structural representation of the downhole fluid induction installation 100 of the present invention, as shown in figure 1, the downhole fluid sensing Device 100 include Venturi tube 12, connecting pipe 13, dividing plate 7, the first spring 3, second spring 4, first piston 5, second piston 6, First grating 1, the second grating 2, Venturi tube 12 is used to guide downhole fluid, and the Venturi tube 12 has the He of an entrance 14 One venturi section 15, the diameter with diameter greater than the venturi section 15 of the entrance 14;Connecting pipe 13 and the Venturi tube 12 Connection;Dividing plate 7 is arranged at the center of the connecting pipe 13;First spring 3 is arranged at the left side of the dividing plate 7, one end of the first spring 3 It is connected with the dividing plate 7, the other end of the first spring 3 is connected with first piston 5, and fluid passes through in the pressure of the entrance 14 The first piston 5 acts on first spring 3;Second spring 4 is symmetricly set in the right side of the dividing plate 7, second spring 4 One end is connected with the dividing plate 7, and the other end of second spring 4 is connected with second piston 6, pressure of the fluid in the venturi section 15 The second spring 4 is acted on by the second piston 6;One end of first grating 1 is connected with the dividing plate 7, the first grating 1 The other end be connected with the first piston 5, first grating 1 flows in the elastic force of the first spring 3 and the entrance 14 All the time extended state is under the collective effect of body pressure, first grating 1 receives incident light, and reflects the first reflection Light;One end of second grating 2 is connected with the dividing plate 7, and the other end of the second grating 2 is connected with the second piston 6, and described Two gratings 2 are in all the time extended state under the collective effect of the elastic force of the second spring 4 and the Fluid pressure of venturi section 15, Second grating 2 receives the incident light, and reflects the second reflected light, and fluid is according to the direction shown in Fig. 1 arrows from text Flow through in venturi 12.
As shown in figure 1, stress (spring force deducts Fluid pressure) that grating is subject to is different, the incident light of reflection is not yet Together, the diameter with diameter greater than the venturi section 15 of the entrance 14, when no fluid flows through Venturi tube 12, or fluid When remaining static, understand that fluid acts on the pressure of first piston 5 in entrance 14 according to Bernoulli equation, equal to fluid The pressure of second piston 6 is acted in venturi section 15, incident light Jing optical grating reflections go out reflected light.When having fluid according to Fig. 1 arrows When shown direction is flow through from Venturi tube 12, due to the diameter with diameter greater than the venturi section 15 of the entrance 14, Fluid is little in the flow velocity of entrance 14 and pressure is big, and fluid is big in the flow velocity of venturi section 15 and pressure is little, now through grating Reflected light will change.
Under normal circumstances, Venturi tube 12 and connecting pipe 13 are located at and are test for scene, such as Venturi tube 12 and pilot In the thousand of rice bran oil gas wells located underground of pipe 13.Because the present invention realizes that rate of flow of fluid is measured using laser, laser has anti-electromagnetism The characteristics such as interference, reliable operation, certainty of measurement height, can be under the conditions of the thousand of rice bran oil gas well high temperatures in underground, hyperbaric environment Realize accurate rate of flow of fluid measurement.
Fig. 2 is a preferred structure schematic diagram of downhole fluid induction installation 100 of the present invention, as shown in Fig. 2 downhole fluid sense Device 100 is answered also to include:First snap ring 8, the second snap ring 9.Wherein, the first snap ring 8 is fixedly installed on the left side of the first piston 5 The inwall of connecting pipe 13 on, the first snap ring 8 is used to limit first piston 5 to left movement, prevents the first grating 1 because stress is excessive Damage;Second snap ring 9 is fixedly installed on the inwall of connecting pipe 13 on the right side of the second piston 6, and the second snap ring 9 is used to limiting the Two pistons 6 are moved right, and prevent the second grating 2 from damaging because stress is excessive, and the first snap ring 8 and the second snap ring 9 relative to every Plate 7 is symmetrical.
As shown in Fig. 2 the setting of the first snap ring 8 and the second snap ring 9 can well protect the first grating 1 and the second grating 2, when out-of-date without fluid stream in Venturi tube 12, pressure is applied to first piston 5 and second piston 6 without fluid, spring Elastic force is all applied on grating, and now, the first snap ring 8 can prevent displacement that first piston 5 occurs to the left beyond described the The maximum tolerance range of one grating 1, the second snap ring 9 can prevent the displacement that second piston 6 occurs to the right from exceeding second light The maximum tolerance range of grid 2, prevents grating because stress is excessive and damages.
As shown in Figure 1 and Figure 2, connecting pipe 13 is arranged along Venturi tube 12, and connecting pipe 13 is tube element, can be effective The lateral dimension of control downhole fluid induction installation 100, so the present invention can measure fluid stream in limited environment space Speed, the such as real-time monitoring of Oil/gas Well downhole fluid flow velocity.Additionally, each element (spring, grating, piston etc.) in connecting pipe 13 It is conventional physical component, therefore downhole fluid induction installation 100 also has simple structure, easy for installation, reliable operation excellent Point, further improves certainty of measurement.
Fig. 3 is the internal structure schematic diagram of the connecting pipe of downhole fluid induction installation 100 of the present invention, as shown in figure 3, described Through hole (not indicating in figure) is provided with dividing plate 7, so can ensure that the pressure in the cavity of dividing plate both sides is in all the time poised state.
As shown in figure 3, setting through hole (not indicating in figure) due to being provided with dividing plate 7, it is ensured that dividing plate 7 and first piston 5 Between left cavity, the air pressure in right cavity between dividing plate 7 and second piston 6 is equal all the time, in left cavity and right cavity Air pressure it is equal can prevent effects of air pressure measurement result, further improve certainty of measurement.
In one embodiment of the present of invention, as shown in Figure 2 and Figure 3, the material of the first piston 5 and the second piston 6 And shape is identical.First piston 5 can occur position with second piston 6 in the range of the first snap ring 8, the second snap ring 9 are limited Move but strict prevention fluid circulation.
As shown in Figure 2 and Figure 3, first piston 5 is identical with the material and shape of second piston 6, it is ensured that first piston 5 It is only relevant with rate of flow of fluid with the pressure that second piston 6 is subject to, not by first piston 5 and the material and shape shadow of second piston 6 Ring, further improve certainty of measurement.
In one embodiment of the present of invention, as shown in Figure 2 and Figure 3, the shape of first grating 1 and second grating 2 And parameters are identical.
As shown in Figure 2 and Figure 3, the first grating 1 is identical with the shape and parameters of the second grating 2, it is ensured that incident light The reflected light formed Jing after the first grating 1 and the second grating 2 reflect, the stress being only subject to the first grating 1 and the second grating 2 (spring force deducts Fluid pressure) is relevant, further improves certainty of measurement.
In one embodiment of the present of invention, as shown in Figure 2 and Figure 3, the shape of first spring 3 and the second spring 4 And parameters are identical.
As shown in Figure 2 and Figure 3, the first spring 3 is identical with the shape and parameters of second spring 4, it is ensured that the first bullet Spring 3 is only subject to first piston 5 relevant with the pressure of second piston 6 with the deformation of the generation of second spring 4 with it, further improves and surveys Accuracy of measurement.Additionally, the detection range of the present invention can be changed by changing the first spring 3 and the elastic modelling quantity of second spring 4, enter One step expands being suitable for for the present invention, provides the user more extensive selection.
Fig. 4 is the structural representation of the Venturi tube 12 of downhole fluid induction installation 100 of the present invention, as shown in figure 4, literary mound In pipe 12 there is entrance 14 and venturi section 15, the diameter with diameter greater than the venturi section 15 of the entrance 14, it is described enter A upstream pilot interface 10 is offered in mouthful section 14, a downstream pilot interface 11, upstream pilot are offered in the venturi section 15 Interface 10 is connected with the left end of connecting pipe 13, and downstream pilot interface 11 is connected with the right-hand member of connecting pipe 13, Venturi tube 12 Interior fluid flows along the entrance 14 to the direction of the venturi section 15.
As shown in Fig. 2 the left end of connecting pipe 13 and the thread connection of upstream pilot interface 10, right-hand member and the downstream of connecting pipe are led The crimping thread connection of mouth 11.In other embodiments of the invention, the left end of connecting pipe 13 is welded with upstream pilot interface 10, pilot The right-hand member of pipe is welded with downstream pilot interface 11, as long as ensureing that connecting pipe 13 is combined with the secure seal of Venturi tube 12, Invention is not limited.
As shown in Fig. 2 connecting pipe 13 adopts thread connection, convenient disassembly, if simply connecting pipe 13 with Venturi tube 12 Or Venturi tube 12 is damaged, without all abandoning, energy-conserving and environment-protective, and reduce maintenance cost.If additionally, fluid need not be sensed Flow velocity, only can unload connecting pipe 13, then with the stopper with mutually suitable screw thread by the upstream pilot interface in Venturi tube 12 10 and downstream pilot interface 11 seal up, without removing Venturi tube 12, convenient use simultaneously immediately.
Fig. 5 is the structural representation of fluid flow measuring systems of the present invention.As shown in figure 5, the fluid flow measuring systems Including the downhole fluid induction installation 100 in above-described embodiment, the fluid flow measuring systems also include a LASER Light Source 200, One grating demodulation instrument 300, a processing meanss 400.The LASER Light Source 200 connects with the downhole fluid flow velocity induction installation 100 Connect, LASER Light Source 200 is used to launch incident light;The grating demodulation instrument 300 is connected with the downhole fluid induction installation 100, Grating demodulation instrument 300 is used to demodulate one first reflectance spectrum of the first reflected light acquisition, demodulates second reflected light and obtains One second reflectance spectrum;The processing meanss 400 are connected with the grating demodulation instrument 300, and processing meanss 400 are used for according to described First reflectance spectrum and second reflectance spectrum obtain the rate of flow of fluid at the entrance 14 of Venturi tube 12, due to Venturi tube The diameter of 12 entrances 14 is equal to the diameter of fluid transmission pipe, so the entrance of Venturi tube 12 that processing meanss 400 are obtained Rate of flow of fluid at 14 is the rate of flow of fluid in fluid transmission pipe (tube fluid flow velocity).
Because the laser direction and unicity of the transmitting of LASER Light Source 200 are good, and do not affected by electromagnetic interference, further Improve the certainty of measurement of the present invention;The good stability of the (FBG) demodulator more non-optical than other of grating demodulation instrument 300, electromagnetism interference enters One step improves fluid measurement precision.
As shown in figure 5, specifically, LASER Light Source 200 launches incident light Jing Optical Fiber Transmissions to the first grating 1 and the second light In grid 2;Incident light forms first reflected light Jing after the reflection of the first grating 1, and incident light forms the Jing after the reflection of the second grating 2 Two reflected lights;First reflected light and the second reflected light Jing Optical Fiber Transmission are in grating demodulation instrument 300;Grating demodulation instrument 300 demodulation, first reflected light obtains the first reflectance spectrum, and grating demodulation instrument demodulates second reflected light and obtains one second Reflectance spectrum, the change of the first reflectance spectrum peak wavelength is proportional to the change of stress suffered by the first grating 1, the second reflectance spectrum The change of peak wavelength is proportional to the change of stress suffered by the second grating 2.
Fig. 6 is the structural representation of the processing meanss 400 of fluid flow measuring systems of the present invention.As shown in fig. 6, the place Reason device 400 include a spectrum acquisition unit 401, a spectrum peak wavelength determining unit 402, a wavelength difference determining unit 403, One pressure differential determining unit 404, a rate of flow of fluid determining unit 405 and a display unit 406.Spectrum acquisition unit 401 is used for Receive first reflectance spectrum and second reflectance spectrum;Spectrum peak wavelength determining unit 402 and the spectrum acquisition Unit 401 connects, and spectrum peak wavelength determining unit 402 is used to determine the first reflectance spectrum peak of first reflectance spectrum Second reflectance spectrum peak wavelength of wavelength and second reflectance spectrum;Wavelength difference determining unit 403 and the spectrum peak Wavelength determining unit 402 connects, and wavelength difference determining unit 403 is used to determine the first reflectance spectrum peak wavelength and described the The difference of two reflectance spectrum peak wavelength;Pressure differential determining unit 404 is connected with the wavelength difference determining unit 403, and pressure differential is true Order unit 404 is used to determine pressure differential that first grating 1 and second grating 2 are subject to according to the difference of the wavelength;Stream Rate of flow of fluid determining unit 405 is connected with the pressure differential determining unit 404, and rate of flow of fluid determining unit 405 is used for according to described Pressure differential determines the flow velocity of fluid in the Venturi tube 12;Display unit 406 connects with the rate of flow of fluid determining unit 405 Connect, display unit 406 is used to show rate of flow of fluid.Due to the feelings determined in wavelength of transmitted light, grating specifications, the elastic coefficient Under condition, the wavelength of reflectance spectrum peak corresponds to the stress that grating is subject to, therefore, pressure differential determining unit 404 is according to described first The difference of reflectance spectrum peak wavelength and the second reflectance spectrum peak wavelength, obtains first grating and second grating The pressure differential (also referred to as stress difference) being subject to.
Pressure differential determining unit 404 is according to the first reflectance spectrum peak wavelength and the second reflectance spectrum peak ripple Long difference, directly obtains pressure differential, calculates simple, it is easy to accomplish, reduce the cost of implementation of the present invention;Rate of flow of fluid determining unit 405 directly obtain rate of flow of fluid according to pressure differential, calculate simple, it is easy to accomplish, further reduce the cost of implementation of the present invention;It is aobvious Show that unit 406 can facilitate tester's observed and recorded with simultaneous display rate of flow of fluid (rate of flow of fluid of entrance 14) so that measurement As a result it is more directly perceived.
As shown in fig. 6, rate of flow of fluid determining unit 405 utilizes primary according to the pressure differential that pressure differential determining unit 404 is obtained Exert the flow velocity (i.e. the rate of flow of fluid of 12 entrance of Venturi tube 14) that sharp equation determines tube fluid.Following formula disclose entrance The relation of equality of 14 fluid flows and the fluid flow of venturi section 15:
A1V1=A2V2(formula 1)
Wherein, A1V1For entrance fluid flow, A2V2For venturi section fluid flow;V1For entrance rate of flow of fluid, V2For Venturi section rate of flow of fluid, A1For entrance cross-sectional area, A2For venturi section cross-sectional area.
Following formula give the cross-sectional area of entrance 14:
(formula 2)
Wherein, A1For entrance cross-sectional area, d1For entrance diameter.
Following formula give the cross-sectional area of venturi section 15:
(formula 3)
Wherein, A2For venturi section cross-sectional area, d2For venturi section diameter.
Following formula are Bernoulli equation:
(formula 4)
Wherein, V1For entrance rate of flow of fluid, V2For venturi section rate of flow of fluid;P1For entrance Fluid pressure, P2For venturi Section Fluid pressure;ρ is fluid density;h1For the vertical height of entrance fluid, h2For the vertical height of venturi section fluid, this Bright middle h1=h2;G is acceleration of gravity.
Can determine by formula 1:
(formula 5)
Wherein, A1V1For entrance fluid flow, A2V2For venturi section fluid flow;V1For entrance rate of flow of fluid, V2For Venturi section rate of flow of fluid, A1For entrance cross-sectional area, A2For venturi section cross-sectional area.
V can determine by formula 2, formula 3, formula 52
(formula 6)
Wherein, d1For entrance diameter, d2For venturi section diameter, V1For entrance rate of flow of fluid, V2For venturi section fluid stream Speed.
V can determine by formula 4, formula 61
(formula 7)
Wherein, P is pressure differential, P=P1-P2, ρ is fluid density, d1For entrance diameter, d2For venturi section diameter.
Can be seen that according to formula 7:When known to the diameter of Venturi tube 12, the rate of flow of fluid in Venturi tube 12 is (i.e. The rate of flow of fluid of entrance 14) it is only relevant with pressure differential P, rate of flow of fluid determining unit 405 can easily draw according to pressure differential P Rate of flow of fluid (the i.e. rate of flow of fluid V of 12 entrance of Venturi tube 14 in pipe1)。
As shown in figure 5, work as fluid in Venturi tube 12 remaining static, or pass through Venturi tube 12 without fluid When, fluid is equal to the pressure that fluid applies to second piston 6, i.e. first piston 5 and second and lives to the pressure that first piston 5 applies The pressure that plug 6 is subject to is identical, and now, the pulling force that the first grating 1 is subject to is that the elastic force of the first spring 3 deducts fluid to first piston 5 pressure for applying, the pulling force that the second grating 2 is subject to deducts fluid to pressing that second piston 6 applies for the elastic force of second spring 4 Power, because the first spring 3 is identical with second spring 4, first piston 5 is identical with second piston 6, so what the first grating 1 was subject to Pulling force is equal to the pulling force that the second grating 2 is subject to.Due to the first grating 1 it is identical with the second grating 2, the He of the first gratings of incident light Jing 1 The the first reflectance spectrum peak wavelength and the second reflectance spectrum peak wavelength that second grating 2 is formed after reflecting is identical, now shows The flow velocity of fluid is 0.
When as arrows in fig. 5 direction flows through Venturi tube 12 to fluid, because the internal diameter of entrance 14 is more than venturi section 15 internal diameter and there is throttling action;The internal diameter of entrance 14 is big and flow velocity is little, and the internal diameter of venturi section 15 is little and flow velocity is big, entrance 14 Place is more than the pressure being subject at venturi section 15 by the pressure of fluid.Now, the pulling force (stress) that the first grating 1 is subject to is first The elastic force of spring 3 deducts the pressure that fluid applies to first piston 5, and the pulling force (stress) that the second grating 2 is subject to is second spring 4 Elastic force deduct the pressure that fluid applies to second piston 6, due to the first spring 3 it is identical with second spring 4, the He of first piston 5 Second piston 6 is identical, so the pulling force that the first grating 1 is subject to is less than the pulling force that the second grating 2 is subject to.Due to the He of the first grating 1 Second grating 2 is identical, the first reflectance spectrum peak wavelength that incident light is formed Jing after the first grating 1 and the second grating 2 reflect and Second reflectance spectrum peak wavelength is no longer equal, and pressure differential determining unit 404 just may be used according to the difference of two reflectance spectrum peak wavelength Obtain the pressure differential of entrance 14 and the fluid of venturi section 15.
Rate of flow of fluid determining unit 405 is asked according to the pressure differential that pressure differential determining unit 404 is obtained using Bernoulli equation Obtain the flow velocity of tube fluid.From formula 7, when the cross-sectional area of entrance 14 and venturi section 15 is decided, entrance 14 or the inner fluid speed of venturi section 15 be directly proportional to the evolution of pressure differential P, for example, it is known that when a diameter of larynx of entrance 14 When 2 times of the diameter of road section 15, the inner fluid speed of venturi section 15 is 4 times of the inner fluid speed of entrance 14, it is assumed that oil density is 1000kg/m3, the rate of flow of fluid (rate of flow of fluid of entrance 14) in an embodiment pipe is as shown in table 1 below:
Table 1
As shown in Table 1 pressure differential determining unit 404 can easily determine rate of flow of fluid, display unit according to pressure differential 406 can facilitate tester's observed and recorded with simultaneous display rate of flow of fluid (rate of flow of fluid of entrance 14), and measurement result is more straight See.
Here, because first piston 5 is identical with second piston 6, the first spring 3 is identical with second spring 4, the first grating 1 It is identical with the second grating 2, it is possible to without considering that the environmental factors such as air pressure, temperature, to the impact caused by measurement result, make Measurement data result is more accurate.
Downhole fluid induction installation provided by the present invention and fluid flow measuring systems compared with prior art, with Lower beneficial effect:
1st, because sensing element grating is placed along connecting pipe 13, the internal diameter of connecting pipe 13 can accomplish very little, therefore can With the lateral dimension of effective control downhole fluid induction installation 100, so present invention can apply to fluid in limited environment space The measurement of flow velocity, the such as real-time monitoring of Oil/gas Well downhole fluid flow velocity.
2nd, the pressure differential asked for using the method that makes the difference before and after Venturi tube 12 throttles of the invention, and the pressure of the left and right sides of dividing plate 7 Power detecting element is identical, thus the impact without the concern for environmental factors such as temperature to measurement result in use, So as to be effectively simplified the processing procedure of measurement data.
3rd, carried out after rate of flow of fluid measurement using the present invention, it is not necessary to which section between piston and pilot interface may be deposited Some part residual fluids are processed, because the fluid of this section only serves the effect of conducting pressure, this is to a great extent Simplify the maintenance process of fluid flow measuring systems.
Schematically specific embodiment of the invention is the foregoing is only, before the design without departing from the present invention and principle Put, the equivalent variations that any those skilled in the art is made with modification, the scope of protection of the invention all should be belonged to.

Claims (9)

1. a kind of downhole fluid induction installation, it is characterised in that the downhole fluid induction installation includes:
One Venturi tube, for guiding downhole fluid, the Venturi tube has an entrance and a venturi section, the entrance The diameter with diameter greater than the venturi section;
One connecting pipe, is connected with the Venturi tube;
One dividing plate, is arranged at the pilot tube hub, wherein, offer through hole on the dividing plate;
One first spring, is arranged at the dividing plate left side, and one end is connected with the dividing plate, and the other end is connected with a first piston, Fluid acts on first spring in the pressure of the entrance by the first piston;
One second spring, is symmetricly set in the dividing plate right side, and one end is connected with the dividing plate, and the other end and a second piston connect Connect, fluid acts on the second spring in the pressure of the venturi section by the second piston;
One first grating, one end is connected with the dividing plate, and the other end is connected with the first piston, and first grating is described All the time extended state is under the collective effect of the first spring force and the entrance Fluid pressure, first grating is received One incident light, and reflect one first reflected light;And
One second grating, one end is connected with the dividing plate, and the other end is connected with the second piston, and second grating is described All the time extended state is under the collective effect of second spring elastic force and the venturi section Fluid pressure, second grating is received The incident light, and reflect one second reflected light.
2. downhole fluid induction installation as claimed in claim 1, it is characterised in that the downhole fluid induction installation also includes:
One first snap ring, is arranged on the pilot inside pipe wall on the left of the first piston;And
One second snap ring, is symmetricly set on the pilot inside pipe wall on the right side of the second piston.
3. downhole fluid induction installation as claimed in claim 1, it is characterised in that the first piston and the second piston It is identical;First grating is identical with second grating;First spring is identical with the second spring.
4. downhole fluid induction installation as claimed in claim 1 a, it is characterised in that upstream is offered on the entrance and is led Crimping mouth, offers a downstream pilot interface in the venturi section, the left end of the connecting pipe connects with the upstream pilot interface Connect, the right-hand member of the connecting pipe is connected with the downstream pilot interface.
5. downhole fluid induction installation as claimed in claim 4, it is characterised in that the left end of the connecting pipe and the upstream Pilot interface thread couples, and the right-hand member of the connecting pipe couples with the downstream pilot interface thread.
6. a kind of fluid flow measuring systems, it is characterised in that the fluid flow measuring systems are included as claim 1-5 is arbitrary Described downhole fluid induction installation, the fluid flow measuring systems also include that a LASER Light Source, a grating demodulation instrument, one are processed Device, wherein, the downhole fluid induction installation includes being arranged at the dividing plate of the pilot tube hub, offers on the dividing plate Through hole;
The LASER Light Source, is connected with the downhole fluid induction installation, for launching the incident light;
The grating demodulation instrument, is connected with the downhole fluid induction installation, and for demodulating first reflected light one is obtained One reflectance spectrum, demodulates second reflected light and obtains one second reflectance spectrum;And
The processing meanss, are connected with the grating demodulation instrument, for according to first reflectance spectrum and second reflection Spectrum determines the rate of flow of fluid at the venturi tube inlet section.
7. fluid flow measuring systems as claimed in claim 6, it is characterised in that the processing meanss include:
One spectrum acquisition unit, for receiving first reflectance spectrum and second reflectance spectrum;
One spectrum peak wavelength determining unit, is connected with the spectrum acquisition unit, for determining first reflection spectrum peak Value wavelength and the second reflectance spectrum peak wavelength;
One wavelength difference determining unit, is connected with the spectrum peak wavelength determining unit, for determining first reflectance spectrum The difference of peak wavelength and the second reflectance spectrum peak wavelength;
One pressure differential determining unit, is connected with the wavelength difference determining unit, for determining institute according to the difference of spectrum peak wavelength State the pressure differential that the first grating and second grating are subject to;And
One rate of flow of fluid determining unit, is connected with the pressure differential determining unit, for determining the text according to the pressure differential Rate of flow of fluid at venturi entrance.
8. fluid flow measuring systems as claimed in claim 7, it is characterised in that under the rate of flow of fluid determining unit is utilized State formula and determine rate of flow of fluid at the venturi tube inlet section:
V 1 = 2 P ρ [ ( d 1 d 2 ) 4 - 1 ] ,
Wherein, V1For entrance rate of flow of fluid, P is pressure differential, and ρ is fluid density, d1For entrance diameter, d2For venturi Duan Zhi Footpath.
9. fluid flow measuring systems as claimed in claim 7, it is characterised in that the processing meanss also include that shows single Unit, is connected, for showing rate of flow of fluid with the rate of flow of fluid determining unit.
CN201410475281.6A 2014-09-17 2014-09-17 Underground fluid induction device and fluid flow velocity measuring system using same Expired - Fee Related CN104389581B (en)

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CN105865544B (en) * 2016-05-30 2019-03-12 贵州大学 The symmetrical damp type flow sensor of double-piston and its detection method
CN105910660B (en) * 2016-05-30 2020-03-24 贵州大学 Momentum type flow sensor and detection method thereof
CN106092217B (en) * 2016-05-30 2019-02-19 贵州大学 A kind of single fiber line quantity sensor and its detection method
CN105806422B (en) * 2016-05-30 2019-08-09 贵州大学 A kind of single fiber line quantity sensor probe and its detection method
CN106092222B (en) * 2016-05-30 2019-03-12 贵州大学 A kind of single-piston optic flow sensor and its detection method
CN106092218B (en) * 2016-05-30 2019-02-12 贵州大学 A kind of dual probe differential pressure flow transducer probe and its detection method
CN105890678A (en) * 2016-05-30 2016-08-24 贵州大学 Momentum type flow sensor probe structure and detection method thereof
CN106052781B (en) * 2016-05-30 2019-03-08 贵州大学 A kind of single-piston optic flow sensor probe and its detection method
CN105865545B (en) * 2016-05-30 2019-04-02 贵州大学 A kind of dual probe differential pressure flow transducer and its detection method

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US7730793B2 (en) * 2007-11-16 2010-06-08 Honeywell International Inc. Venturi flow sensor
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