CA2201114C - A mixer and apparatus for analysing fluid flow - Google Patents
A mixer and apparatus for analysing fluid flow Download PDFInfo
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- CA2201114C CA2201114C CA002201114A CA2201114A CA2201114C CA 2201114 C CA2201114 C CA 2201114C CA 002201114 A CA002201114 A CA 002201114A CA 2201114 A CA2201114 A CA 2201114A CA 2201114 C CA2201114 C CA 2201114C
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- 239000012530 fluid Substances 0.000 title claims abstract description 32
- 230000003068 static effect Effects 0.000 claims abstract description 29
- 239000007788 liquid Substances 0.000 claims description 14
- 238000011144 upstream manufacturing Methods 0.000 claims description 11
- 238000005259 measurement Methods 0.000 claims description 7
- 230000000630 rising effect Effects 0.000 claims description 3
- 238000012544 monitoring process Methods 0.000 claims description 2
- 230000005855 radiation Effects 0.000 abstract description 53
- 238000012545 processing Methods 0.000 abstract description 16
- 238000004458 analytical method Methods 0.000 abstract description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 8
- 238000000034 method Methods 0.000 abstract description 6
- 239000003129 oil well Substances 0.000 abstract description 5
- 241001298365 Arion ater Species 0.000 abstract description 2
- 239000000203 mixture Substances 0.000 description 7
- 229910052792 caesium Inorganic materials 0.000 description 5
- TVFDJXOCXUVLDH-UHFFFAOYSA-N caesium atom Chemical compound [Cs] TVFDJXOCXUVLDH-UHFFFAOYSA-N 0.000 description 5
- 238000004364 calculation method Methods 0.000 description 5
- 238000010521 absorption reaction Methods 0.000 description 4
- 230000003247 decreasing effect Effects 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 238000000265 homogenisation Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 238000012935 Averaging Methods 0.000 description 1
- 241000252233 Cyprinus carpio Species 0.000 description 1
- 241000237858 Gastropoda Species 0.000 description 1
- 230000001174 ascending effect Effects 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000005206 flow analysis Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 238000007619 statistical method Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/02—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material
- G01N23/06—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption
- G01N23/12—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption the material being a flowing fluid or a flowing granular solid
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
- B01F25/40—Static mixers
- B01F25/42—Static mixers in which the mixing is affected by moving the components jointly in changing directions, e.g. in tubes provided with baffles or obstructions
- B01F25/43—Mixing tubes, e.g. wherein the material is moved in a radial or partly reversed direction
- B01F25/432—Mixing tubes, e.g. wherein the material is moved in a radial or partly reversed direction with means for dividing the material flow into separate sub-flows and for repositioning and recombining these sub-flows; Cross-mixing, e.g. conducting the outer layer of the material nearer to the axis of the tube or vice-versa
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
- B01F25/40—Static mixers
- B01F25/42—Static mixers in which the mixing is affected by moving the components jointly in changing directions, e.g. in tubes provided with baffles or obstructions
- B01F25/43—Mixing tubes, e.g. wherein the material is moved in a radial or partly reversed direction
- B01F25/431—Straight mixing tubes with baffles or obstructions that do not cause substantial pressure drop; Baffles therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
- B01F25/40—Static mixers
- B01F25/42—Static mixers in which the mixing is affected by moving the components jointly in changing directions, e.g. in tubes provided with baffles or obstructions
- B01F25/43—Mixing tubes, e.g. wherein the material is moved in a radial or partly reversed direction
- B01F25/431—Straight mixing tubes with baffles or obstructions that do not cause substantial pressure drop; Baffles therefor
- B01F25/4315—Straight mixing tubes with baffles or obstructions that do not cause substantial pressure drop; Baffles therefor the baffles being deformed flat pieces of material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
- B01F25/40—Static mixers
- B01F25/42—Static mixers in which the mixing is affected by moving the components jointly in changing directions, e.g. in tubes provided with baffles or obstructions
- B01F25/43—Mixing tubes, e.g. wherein the material is moved in a radial or partly reversed direction
- B01F25/431—Straight mixing tubes with baffles or obstructions that do not cause substantial pressure drop; Baffles therefor
- B01F25/4317—Profiled elements, e.g. profiled blades, bars, pillars, columns or chevrons
- B01F25/43171—Profiled blades, wings, wedges, i.e. plate-like element having one side or part thicker than the other
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/02—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material
- G01N23/06—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption
- G01N23/083—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption the radiation being X-rays
Landscapes
- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Analytical Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Physics & Mathematics (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Toxicology (AREA)
- Measuring Volume Flow (AREA)
- Indicating Or Recording The Presence, Absence, Or Direction Of Movement (AREA)
Abstract
A static mixer (22) is provided for one or more fluids flowing in a pipe (108), such as oil, water and gas from an oil well. The mixer (22) comprises an element (112, 114) to divide the flowing fluids into at least two streams within the pipe (108) and to deflect two of the resulting streams so that those streams rotate in opposite senses about axes parallel to the direction of flow of the fluid, the element (112, 114) being shaped so as to maintain movement of the flow in a substantially smooth manner. Apparatus (10) is provided for analysing fluid flow in a pipe (108) comprising at least one radiation source (12, 14) to direct radiation through the flow, and at least one radiation detector (12, 14) positioned to receive from the source or sources radiation which has passed through the flow, the source or sources emitting radiation at least at two different energies. The or each detector provides a signal to a processing unit (20) which is arranged to process the signal to provide a series of chronological values, to group the values by magnitude and to analyse the grouped values, for example, to determine phase fraction, type of flow e.g. slug flow, and flow rate.
Description
220' 1 1 ~
A tdIXER AND APPARATUS FOR ANALY~IP3G FLUID FLOW
The invention relates to a mixer and apparatus for analysing fluid flow.
Mixers are widely used in a number of industries. One such industry is the oil industry. Oil wells produce a mixture of oil, water and gas and homogenisation of these components is desirable for accurate flow measurement.
EP 0395635 discloses a number of static miner devices.
One sucl-~ device has a plate arranged normal to the flow through the pipe. The plate has two apertures and two curved vanes ofsheet material lie directly E=
behind these apertures. Fluids flowing in the pipe will pass through one or other of the apertures to be divided into two streams and will be deflected by the r.
vanes to rotate in opposite senses about axes parallel to the direction of flow of the fluid and will thus be homogenised.
1' According to one aspect of the present invention there ' is provided a static mixer far one or more fluids flowing in a pipe, the mixer comprising an element to divide the f lowing fluids ir~to at least two strearc~s within the pipe and to deflect two of the resulting WO 96/09880 PCTlGB95/02294 4 2~0~ 1~ ~
A tdIXER AND APPARATUS FOR ANALY~IP3G FLUID FLOW
The invention relates to a mixer and apparatus for analysing fluid flow.
Mixers are widely used in a number of industries. One such industry is the oil industry. Oil wells produce a mixture of oil, water and gas and homogenisation of these components is desirable for accurate flow measurement.
EP 0395635 discloses a number of static miner devices.
One sucl-~ device has a plate arranged normal to the flow through the pipe. The plate has two apertures and two curved vanes ofsheet material lie directly E=
behind these apertures. Fluids flowing in the pipe will pass through one or other of the apertures to be divided into two streams and will be deflected by the r.
vanes to rotate in opposite senses about axes parallel to the direction of flow of the fluid and will thus be homogenised.
1' According to one aspect of the present invention there ' is provided a static mixer far one or more fluids flowing in a pipe, the mixer comprising an element to divide the f lowing fluids ir~to at least two strearc~s within the pipe and to deflect two of the resulting WO 96/09880 PCTlGB95/02294 4 2~0~ 1~ ~
2 streams so that those streams rotate in opposite senses about axes parallel to the direction of flow of the fluid, the element being shaped so as to maintain , movement of the flow in a substantially smooth manner.
In this way, effective homogenisation can be obtained without introducing unnecessary turbulence ar otherwise unduly disturbing the flow.
The mixer of the invention. provides adequate mixing over a wide range of flow conditions thus allowing accurate measurements to be made of phase fraction and velocity at points downstream of the mixer using single narrow gamra or X-ray beams or other established techniques.
Without adequate mixing the phases are rot homogeneously distributed across the pipe section, witr~ the result that a singly narrow beam may give an erroneous indication of tree phase contents due to norm-uniformity and the exponential nature of the photon absorption. Furthermore, without adequate nixing the phases move at different velocities and a single velocity measurement does not give an accurate measure , of the flow rates but must be corrected by the use of theoretical models or correlatior~s to account for the relative velocities of the phases. This inver~tior~
ZZO~~~~
In this way, effective homogenisation can be obtained without introducing unnecessary turbulence ar otherwise unduly disturbing the flow.
The mixer of the invention. provides adequate mixing over a wide range of flow conditions thus allowing accurate measurements to be made of phase fraction and velocity at points downstream of the mixer using single narrow gamra or X-ray beams or other established techniques.
Without adequate mixing the phases are rot homogeneously distributed across the pipe section, witr~ the result that a singly narrow beam may give an erroneous indication of tree phase contents due to norm-uniformity and the exponential nature of the photon absorption. Furthermore, without adequate nixing the phases move at different velocities and a single velocity measurement does not give an accurate measure , of the flow rates but must be corrected by the use of theoretical models or correlatior~s to account for the relative velocities of the phases. This inver~tior~
ZZO~~~~
3 avoids the need far such corrections and their associated uncertainty.
Further, the characteristics of the mixer of the invention are such that the differential pressure across the mixer, when combined with phase fraction information, will provide an accurate measurement of velocity of the flowing fluids over a wide range of flow conditions, including slug flow.
Preferably, the element includes a smoothly contoured surface leading to the part of the element which divides the flowing fluids. Preferably further, the element includes a smoothly contoured surface which leads away from the part of the element which deflects two of the resulting streams so that those streams rotate in opposite senses.
Preferably, the part of the element which divides the flowing fluids into at least two streams within the pipe extends over a significant axial distance which may be about a half to three-quarters of a diameter of the pipe and preferably is about five-eighths of the ' diameter of the pipe. As the separation of the flows takes place over a significant distance, undue turbulence and disturbance are avoided. Preferably, the part of the element which deflects two of the ,22011~~
Further, the characteristics of the mixer of the invention are such that the differential pressure across the mixer, when combined with phase fraction information, will provide an accurate measurement of velocity of the flowing fluids over a wide range of flow conditions, including slug flow.
Preferably, the element includes a smoothly contoured surface leading to the part of the element which divides the flowing fluids. Preferably further, the element includes a smoothly contoured surface which leads away from the part of the element which deflects two of the resulting streams so that those streams rotate in opposite senses.
Preferably, the part of the element which divides the flowing fluids into at least two streams within the pipe extends over a significant axial distance which may be about a half to three-quarters of a diameter of the pipe and preferably is about five-eighths of the ' diameter of the pipe. As the separation of the flows takes place over a significant distance, undue turbulence and disturbance are avoided. Preferably, the part of the element which deflects two of the ,22011~~
4 resulting streams so that those streams rotate in opposite senses extends over a significant axial distance which may be a half to three-quarters of a diameter of the pipe and preferably is about five-eighths~of a diamEter of the pipe.
Preferably, the surface of the element wl-~ich faces downstream defines a substantial absence of cavities facing downstream. Preferably, the surface of the element which faces upstream defines a substantial absence of cavities facing upstream.
Preferably further, substantially the entire impingement surface of the element is at ar~ angle of no greater than 85°, preferably 80°, most preferably 'C°
to the flow direction. Preferably, substantially the entire past impingement surface Of the 8lement is at an angle of ro greater than 85° to the flow direction, preferably 75°, most preferably EO°. Preferably the maximum angle of direction change of the flaw surface of the element is 9C°, most preferably ~0°.
The most upstream part of the element may comprise a part which presents a rising slope from an inner wall of the pipe to a ridge andl~ay then present a descer~ding slope back to the inner wall of the pipe.
The element iiiay comprise a central wall part which 220 1 ~ 1 ~
divides the pipe into two. The element may comprise a pair of handed curved parts which direct the flow through an angle of 60° to 120°, preferably 80° to 100°, most preferably about 90°.
Preferably, the surface of the element wl-~ich faces downstream defines a substantial absence of cavities facing downstream. Preferably, the surface of the element which faces upstream defines a substantial absence of cavities facing upstream.
Preferably further, substantially the entire impingement surface of the element is at ar~ angle of no greater than 85°, preferably 80°, most preferably 'C°
to the flow direction. Preferably, substantially the entire past impingement surface Of the 8lement is at an angle of ro greater than 85° to the flow direction, preferably 75°, most preferably EO°. Preferably the maximum angle of direction change of the flaw surface of the element is 9C°, most preferably ~0°.
The most upstream part of the element may comprise a part which presents a rising slope from an inner wall of the pipe to a ridge andl~ay then present a descer~ding slope back to the inner wall of the pipe.
The element iiiay comprise a central wall part which 220 1 ~ 1 ~
divides the pipe into two. The element may comprise a pair of handed curved parts which direct the flow through an angle of 60° to 120°, preferably 80° to 100°, most preferably about 90°.
5 The element may be made in any suitable fashion and preferably is produced in one or two pieces, for example, by casting or moulding.
According to another aspect of the invention, there is provided apparatus for monitoring flow comprising a mixer according to the first aspect of the invention and means for measuring the pressure drop across the mixer.
By means of the measurement of the pressure drop, flow rate calculations can be carried out.
Preferably, in particular when used for metering mixtures of liquid and gas, the apparatus further includes means for measuring liquid hold-up after the mixer. By measuring the pressure drop and the liquid hold-up, the total velocity of the fluid in the pipe ' and the liquid flow rate can be calculated.
The means far measuring liquid hold-up may take any suitable farm and may comprise phase fraction or 9 22A~ ~1.
According to another aspect of the invention, there is provided apparatus for monitoring flow comprising a mixer according to the first aspect of the invention and means for measuring the pressure drop across the mixer.
By means of the measurement of the pressure drop, flow rate calculations can be carried out.
Preferably, in particular when used for metering mixtures of liquid and gas, the apparatus further includes means for measuring liquid hold-up after the mixer. By measuring the pressure drop and the liquid hold-up, the total velocity of the fluid in the pipe ' and the liquid flow rate can be calculated.
The means far measuring liquid hold-up may take any suitable farm and may comprise phase fraction or 9 22A~ ~1.
6 liquid fraction measurement instruments. Tree or each measuring means may comprise at least one radiation source such as an x-ray or preferably gamma radiation source and at Ieast one radiation sensor. The smooth through flow enabled by the mixer of the invention enables consistent and accurate calculations to be carried out of total mixture velocity and mean flow rates. This is particularly important, for example, where oil is produced from one or a group of oil wells. The total homogenised mixture velocity together with phase fraction information can be used to calculate the proportions arid quantities of oil, gas and water being produced. Indeed an accuracy of better than 5% carp be achieved with this technique over a wide range of flow conditions which represents a considerable improvement over prior techniques.
Freferably the radiation source or sources are arranged to emit radiation at least at two different energies and at least one radiation detector is provided positioned to receive from t3-~e source or sour Ces r ad I at 5. 'vn W h 3. Ch has gassed th rough the f i OW , the source or source's emitting radiation at least at two different energies, tree or each detector providing a signal to processing means, the processing means being arranged to process the signal to provide a series of chronological values and to group the values
Freferably the radiation source or sources are arranged to emit radiation at least at two different energies and at least one radiation detector is provided positioned to receive from t3-~e source or sour Ces r ad I at 5. 'vn W h 3. Ch has gassed th rough the f i OW , the source or source's emitting radiation at least at two different energies, tree or each detector providing a signal to processing means, the processing means being arranged to process the signal to provide a series of chronological values and to group the values
7 by magnitude far analysis by analysis means.
' One situation in which fluid flow analysis is important is in the production of oil from an oil well, or group of oil wells. OiI is commonly found mixed with water and gas thus providing a three phase fluid flow. Clearly, it is important to be able to determine how much of the fluid flow is constituted by each of the three phases.
Known apparatus for phase fraction analysis comprises two gamma radiation sources with associated detectors, which are spaced apart along a pipe in the flow direction. The sources emit radiation at different energies. The signals fron the detectors are proportional to the gamma radiation. received and hence indicate the radiation absorption. from the flow. This information enables the phase fractions of the flow to be determined. The phase fractions of the flow may vary widely with time as the flow passes the detectors due the occurrence of slug flow, for example, and the analysis is consequently subject to inaccuracy, particularly as the relationship between radiation absorption and the amount of fluid intercepting the beam is exponential.
According to another aspect of the invention there is WO 96/09880 s ~ PCT/GB95/02294
' One situation in which fluid flow analysis is important is in the production of oil from an oil well, or group of oil wells. OiI is commonly found mixed with water and gas thus providing a three phase fluid flow. Clearly, it is important to be able to determine how much of the fluid flow is constituted by each of the three phases.
Known apparatus for phase fraction analysis comprises two gamma radiation sources with associated detectors, which are spaced apart along a pipe in the flow direction. The sources emit radiation at different energies. The signals fron the detectors are proportional to the gamma radiation. received and hence indicate the radiation absorption. from the flow. This information enables the phase fractions of the flow to be determined. The phase fractions of the flow may vary widely with time as the flow passes the detectors due the occurrence of slug flow, for example, and the analysis is consequently subject to inaccuracy, particularly as the relationship between radiation absorption and the amount of fluid intercepting the beam is exponential.
According to another aspect of the invention there is WO 96/09880 s ~ PCT/GB95/02294
8 provided apparatus for analysing fluid flow in a pipe compris..ing at least one radiation source to direct radiation through the flow, and at least one radiation detector positioned to receive from the source or sources~radiation which has passed through the flow, the source or sources emitting radiation at least at two different energies, the or each detector providing a signal to processing means, the processing means being arranged to process the signal to provide a series of chronological values and to group the values by magnitude for analysis by analysis means.
As the signal becomes a series of values which are grouped, the analysis means car conduct a more sophisticated analysis than simple averaging and a more accurate analysis can be conducted. Preferably, the analysis means is arranged to determine the phase fractions in the flow. Alternatively, or in addition, the analysis means may be arranged to determine the type of flow e.g. slug flow or stratified flow. In addition the analysis of the signals by grouping provides information on the variation of composition of the mixture with time. For example in slug flow the oil/water ratios in the slug and in the thin film between slugs can be individually determined.
Preferably, radiation from the or each source will be 22~ 11 ~ ~
As the signal becomes a series of values which are grouped, the analysis means car conduct a more sophisticated analysis than simple averaging and a more accurate analysis can be conducted. Preferably, the analysis means is arranged to determine the phase fractions in the flow. Alternatively, or in addition, the analysis means may be arranged to determine the type of flow e.g. slug flow or stratified flow. In addition the analysis of the signals by grouping provides information on the variation of composition of the mixture with time. For example in slug flow the oil/water ratios in the slug and in the thin film between slugs can be individually determined.
Preferably, radiation from the or each source will be 22~ 11 ~ ~
9 measured over a series of'short time intervals. In one embodiment, a single detector is provided. In that case, two sources may be provided, each emitting radiation at a different energy. In the prior system, necessary separation of the two sources lead to errors as the radiation beams did not "see" the same section of flow. Because of the processing and analysis which is carried out by the apparatus of the invention, this necessary separation is possible without incurring errors.
As an alternative to two sources, a single source can be used which is arranged to emit radiation of at least two different energies, e.g. a caesium source emitting radiation at 32 keV and 661 keV.
The apparatus is principally intended for use with three phase flow and so preferably radiation at only two different energies is emitted by the source or sources.
The radiation may be X-ray and/or gamma radiation.
The apparatus may include a nixer and means for sensing pressure drop across the mixer. This enables f velocity calculations to be carried out when combined with means for sensing liquid hold-up. The sensing means are preferably associated with the analysis means which is arranged to determine flow rate. The means for sensing the liquid hold-up may camgrise at , least one radiation source to direct radiation through 5 the flow to at least one radiation detector positioned to receive radiation which has passed through the flow from the or each source.
In one embodiment, the apparatus includes only two
As an alternative to two sources, a single source can be used which is arranged to emit radiation of at least two different energies, e.g. a caesium source emitting radiation at 32 keV and 661 keV.
The apparatus is principally intended for use with three phase flow and so preferably radiation at only two different energies is emitted by the source or sources.
The radiation may be X-ray and/or gamma radiation.
The apparatus may include a nixer and means for sensing pressure drop across the mixer. This enables f velocity calculations to be carried out when combined with means for sensing liquid hold-up. The sensing means are preferably associated with the analysis means which is arranged to determine flow rate. The means for sensing the liquid hold-up may camgrise at , least one radiation source to direct radiation through 5 the flow to at least one radiation detector positioned to receive radiation which has passed through the flow from the or each source.
In one embodiment, the apparatus includes only two
10 sources and only two detectors and the ar~alysis means is arranged to determine both phase faction and flow rate. Phase fraction is determined using two energies from one of the sources and velocity is dEterz~ined by corpar ison of the dynamic radial.lVr1 slgrtals received by the two detectors spaced axially along the pipe.
This arrangement uses the minimum number of compor~enis arid is thus particularly simple and cost advantageous.
One embOdlZent Of the inventlOn wiii nOw be described by way of example arid with reference to the accompanying drawings, ir~ which:
Fig. 1 is a side elevation in partial cross-section of the apparatus of the embodiment; , Fig. 2 is a perspective view of the mixer of the embodiment;
Fig. 3 is a side elevation of the mixer of the 22011 1 ~
This arrangement uses the minimum number of compor~enis arid is thus particularly simple and cost advantageous.
One embOdlZent Of the inventlOn wiii nOw be described by way of example arid with reference to the accompanying drawings, ir~ which:
Fig. 1 is a side elevation in partial cross-section of the apparatus of the embodiment; , Fig. 2 is a perspective view of the mixer of the embodiment;
Fig. 3 is a side elevation of the mixer of the 22011 1 ~
11 embodiment; and, Fi..g. 4 is a plan view of the mixer of the embodiment.
The apparatus 10 comprises two gamma radiation units
The apparatus 10 comprises two gamma radiation units
12,14, two pressure transducers 16,18 and a central processing unit 20.
The pressure transducers 16,18 are provided on either side of a static flow mixer 22 within the pipe 24.
The pressure transducers 16,18 are connected to the central processing unit 20. Downstream of the mixer 22 is provided a temperature sensor 26 which is also connected to the central processing unit 20. Just downstream of the temperature sensor 26 is provided the first gamma radiation unit 12. The first gamma radiation unit 12 comprises a caesium source of energies 32 keV and 661 keV. The source directs its radiation through the pipe 24 to a single detector to the other side of the pipe 24. The detector is connected to an amplifier and analyzer 28 which has high and Iow outputs to the central processing unit 20. The amplifier and channel analyzer 28. is powered ' by a DC power supply 30 adjacent the central processing unit 20. Downstream of the first radiation unit 12 is provided the second radiation unit 14.
This includes a single 661 keV caesium source a d n a WO 96/09880 ~ PCT/GB95l02294 thick crystal detector which is connected to a second amplifier and analyzer 32 which is also powered by the power supply 30 and is also connected to the central processing unit 20.
In use, a three pr~ase fluid flow of oil, water and gas flows through the pipe 24 and through the mixer 22.
The temperature sensor 26 senses its temperature and the pressure transducers 16,18 upstream arid downstream of the mixer 22 provide pressure information to the central processing unit 20 to enable to pressure drop across the mixer 22 to be determined. High and Iow energy radiation from the source of the first radiation unit 12 is detected by the single detector of the first radiation unit 12 after absorption through the fluid and is processed and analyzed by the central processing unit 20 together with the signals from the second radiation unit 14. The signals from the first radiation unit 12 are chronologically divided and grouped into bands by magnitude far statistical analysis by the central processing unit 20 (whicl-~ constitutes the aforesaid "processing means"
and "analyzing means"~ to enable an accurate determination of phase fraction to be made. Second radiation unit 1~ in combination with tl-~e signal from the first radiation unit 12 enables velocity to be calculated and this information together with the 2~0~~~~
R'O 96/09880 PCT/GB95/02294
The pressure transducers 16,18 are provided on either side of a static flow mixer 22 within the pipe 24.
The pressure transducers 16,18 are connected to the central processing unit 20. Downstream of the mixer 22 is provided a temperature sensor 26 which is also connected to the central processing unit 20. Just downstream of the temperature sensor 26 is provided the first gamma radiation unit 12. The first gamma radiation unit 12 comprises a caesium source of energies 32 keV and 661 keV. The source directs its radiation through the pipe 24 to a single detector to the other side of the pipe 24. The detector is connected to an amplifier and analyzer 28 which has high and Iow outputs to the central processing unit 20. The amplifier and channel analyzer 28. is powered ' by a DC power supply 30 adjacent the central processing unit 20. Downstream of the first radiation unit 12 is provided the second radiation unit 14.
This includes a single 661 keV caesium source a d n a WO 96/09880 ~ PCT/GB95l02294 thick crystal detector which is connected to a second amplifier and analyzer 32 which is also powered by the power supply 30 and is also connected to the central processing unit 20.
In use, a three pr~ase fluid flow of oil, water and gas flows through the pipe 24 and through the mixer 22.
The temperature sensor 26 senses its temperature and the pressure transducers 16,18 upstream arid downstream of the mixer 22 provide pressure information to the central processing unit 20 to enable to pressure drop across the mixer 22 to be determined. High and Iow energy radiation from the source of the first radiation unit 12 is detected by the single detector of the first radiation unit 12 after absorption through the fluid and is processed and analyzed by the central processing unit 20 together with the signals from the second radiation unit 14. The signals from the first radiation unit 12 are chronologically divided and grouped into bands by magnitude far statistical analysis by the central processing unit 20 (whicl-~ constitutes the aforesaid "processing means"
and "analyzing means"~ to enable an accurate determination of phase fraction to be made. Second radiation unit 1~ in combination with tl-~e signal from the first radiation unit 12 enables velocity to be calculated and this information together with the 2~0~~~~
R'O 96/09880 PCT/GB95/02294
13 calculation of pressure 'drop enables the total and phase flow rates to be determined. The temperature sensor information is needed to take account of the fact that t1-.e gas constitutes a compressible phase.
Alternatively, or in addition, velocity may be derived from pressure drop across the mixer such that the second radiation unit 14 may be omitted.
Figs. 2 to 4 show the mixer 22 in more detail. The mixer 22 of the embodiment is cast as a single piece, but can be considered to comprise two parts 1.2,114.
The mixer 22 is provided in a cylindrical pipe 108.
The first part 112 rises from the floor of the pipe 108 presenting a flat surface 116 to the oncoming flow of fluid through the pipe 108 at an ar~gle of about 20°
to the longitudinal axis of the pipe 108. The surface 116 rises to a smoothly curved ridge 118 of height W
from which it descends again as a flat surface 120 at an angle of about 40° to the axis of the pipe 108, the angle of descent decreasing close to the floor of the pipe 108 so that the surface 120 smoothly curves to meet the floor of the pipe 108.
The second part 114 is formed to its upstream side as an upright wall 124 of constant thickness and with a rounded front edge 126 against which incoming flow WO 96!09880 PCT/GB95/02294
Alternatively, or in addition, velocity may be derived from pressure drop across the mixer such that the second radiation unit 14 may be omitted.
Figs. 2 to 4 show the mixer 22 in more detail. The mixer 22 of the embodiment is cast as a single piece, but can be considered to comprise two parts 1.2,114.
The mixer 22 is provided in a cylindrical pipe 108.
The first part 112 rises from the floor of the pipe 108 presenting a flat surface 116 to the oncoming flow of fluid through the pipe 108 at an ar~gle of about 20°
to the longitudinal axis of the pipe 108. The surface 116 rises to a smoothly curved ridge 118 of height W
from which it descends again as a flat surface 120 at an angle of about 40° to the axis of the pipe 108, the angle of descent decreasing close to the floor of the pipe 108 so that the surface 120 smoothly curves to meet the floor of the pipe 108.
The second part 114 is formed to its upstream side as an upright wall 124 of constant thickness and with a rounded front edge 126 against which incoming flow WO 96!09880 PCT/GB95/02294
14 will impinge. The wall 124 intersects the rising surface.116 of the first part 112. Just past the ridge 118, the shape of the second part 114 changes.
The lower edge of this central section 128 of the second part 114 continues at the height of the ridge 118, and at the same thickness as the wall 124. The upper part of the central section 128 broadens increasingly in a smoothly curved manner. The degree of broadening of the central section 128 increases along the axis of the pipe until the second part 114 intersects the wall of the pipe 108 at the level of the ridge 118 at which point the angle of the curved surface to the axis of the pipe is about 70°. The downstream section 130 of the second part 114 smoothly curves back towards the wall of tree pipe 108 at an increasing angle to the axis of the pipe 108 the greatest angle being about 60° just before intersection with the pipe 108.
In use, flow, for example, of oil, gas and water, passes along the pipe 108 and first impinges upon the ascending surface 116 of the first part which restricts the flow area of the pipe 108. Once the flow reaches the wall 124 it is divided into two and continues to be further restricted until reaching the ridge 118. As the central section 128 of the second part 114 broadens, each flow is subjected to induced z~o~~~~
1~
J
rotation, the flows being rotated in different directions. The downstream section 130 of the second part 114 and the descending slope 120 of the first part then slope away from the axis of the pipe 108 and the flew area thus broadens out and the homogenised mixed fluid passes further through the pipe 108. It is thus seen that fluid is smoothly guided through the mixer 22.
The distance A from the upstream edge of the surface 116 to intersection with the upstream edge 126 of the wall 124 may be about seven-eighths of the diameter B
of the pipe 108. The distance C from the upstream edge 126 of the wall 124 to the ridge 118 may be about five-eighths of the diameter B of the pipe 108. The distance D from the ridge 118 to the end of the central section 128 of the second part 114 may be five-eighths of the diameter B of the pipe 108. The distance E from t1-~e end of the central section 128 to the downstream edge of the downstream section 130 of the second part 114, which is further downstream than the downstream edge of the first part 112, may be about nine-sixteenths of the diameter of the pipe.
The diameter of the pipe may be about 80-180mm arid in a particular embcdimer~t is 80mm.
Gamma or X-ray sources arid sensors or other means may be provided after the mixer 22 to enable the liquid hold-up..to be measured and transducers may be provided to measure pressure drop across tree mixer 22 to thereby enable calculation of the total mixture velocity. It has been established experimentally tat r tree pressure drop DQ is linearly related to the product of total and superficial liquid velocities Vt, V~ .
Dp = a + b Vt VL
The I i qu i d ho 1 d-up EL i s g i ven by E~ - VL /Vt .
Thus . Vt = ( (DF-a}/(bE~} ~~
where a and b are calibration factors dependent mainly upon the properties of the flow components. Because of the nature of tl-~e mixer in producing good 1-~omogenisation without undue flow disturbance, tl-~e factors a and b are relatively insensitive to the ratio of components in particular water, oil and gas.
This is unlike the prior static mixers of EP 0395635 for example which produce conditions under which the relevant equations do not hold true with sufficient accuracy. By means of the invention multiphase total velocities and superficial liquid velocities can be .
measured with an accuracy of better than 5~.
220~~~~
The first radiation unit 12 may include two distinct caesium.sources, or a single caesium source capable of . radiating at both energies. Clearly, other types of radiation source may be used.
In a further etr~bodiment, the first radiation unit 12 and second radiation unit 14 use different energies and source of only a single energy is provided in the first radiation unit.
Clearly the dimensions of the mixer may be varied in different embodiments. The height W of the ridge 118 may be increased to provide a smaller restriction for the flow to pass through, or may be decreased. The length D of the central section 128 which rotates the two streams may be increased to further smooth the flow, or may be decreased. The differential pressure across the mixer can be adjusted in this way to suit the particular installation.
r .v. . . . . . ; . .:
The lower edge of this central section 128 of the second part 114 continues at the height of the ridge 118, and at the same thickness as the wall 124. The upper part of the central section 128 broadens increasingly in a smoothly curved manner. The degree of broadening of the central section 128 increases along the axis of the pipe until the second part 114 intersects the wall of the pipe 108 at the level of the ridge 118 at which point the angle of the curved surface to the axis of the pipe is about 70°. The downstream section 130 of the second part 114 smoothly curves back towards the wall of tree pipe 108 at an increasing angle to the axis of the pipe 108 the greatest angle being about 60° just before intersection with the pipe 108.
In use, flow, for example, of oil, gas and water, passes along the pipe 108 and first impinges upon the ascending surface 116 of the first part which restricts the flow area of the pipe 108. Once the flow reaches the wall 124 it is divided into two and continues to be further restricted until reaching the ridge 118. As the central section 128 of the second part 114 broadens, each flow is subjected to induced z~o~~~~
1~
J
rotation, the flows being rotated in different directions. The downstream section 130 of the second part 114 and the descending slope 120 of the first part then slope away from the axis of the pipe 108 and the flew area thus broadens out and the homogenised mixed fluid passes further through the pipe 108. It is thus seen that fluid is smoothly guided through the mixer 22.
The distance A from the upstream edge of the surface 116 to intersection with the upstream edge 126 of the wall 124 may be about seven-eighths of the diameter B
of the pipe 108. The distance C from the upstream edge 126 of the wall 124 to the ridge 118 may be about five-eighths of the diameter B of the pipe 108. The distance D from the ridge 118 to the end of the central section 128 of the second part 114 may be five-eighths of the diameter B of the pipe 108. The distance E from t1-~e end of the central section 128 to the downstream edge of the downstream section 130 of the second part 114, which is further downstream than the downstream edge of the first part 112, may be about nine-sixteenths of the diameter of the pipe.
The diameter of the pipe may be about 80-180mm arid in a particular embcdimer~t is 80mm.
Gamma or X-ray sources arid sensors or other means may be provided after the mixer 22 to enable the liquid hold-up..to be measured and transducers may be provided to measure pressure drop across tree mixer 22 to thereby enable calculation of the total mixture velocity. It has been established experimentally tat r tree pressure drop DQ is linearly related to the product of total and superficial liquid velocities Vt, V~ .
Dp = a + b Vt VL
The I i qu i d ho 1 d-up EL i s g i ven by E~ - VL /Vt .
Thus . Vt = ( (DF-a}/(bE~} ~~
where a and b are calibration factors dependent mainly upon the properties of the flow components. Because of the nature of tl-~e mixer in producing good 1-~omogenisation without undue flow disturbance, tl-~e factors a and b are relatively insensitive to the ratio of components in particular water, oil and gas.
This is unlike the prior static mixers of EP 0395635 for example which produce conditions under which the relevant equations do not hold true with sufficient accuracy. By means of the invention multiphase total velocities and superficial liquid velocities can be .
measured with an accuracy of better than 5~.
220~~~~
The first radiation unit 12 may include two distinct caesium.sources, or a single caesium source capable of . radiating at both energies. Clearly, other types of radiation source may be used.
In a further etr~bodiment, the first radiation unit 12 and second radiation unit 14 use different energies and source of only a single energy is provided in the first radiation unit.
Clearly the dimensions of the mixer may be varied in different embodiments. The height W of the ridge 118 may be increased to provide a smaller restriction for the flow to pass through, or may be decreased. The length D of the central section 128 which rotates the two streams may be increased to further smooth the flow, or may be decreased. The differential pressure across the mixer can be adjusted in this way to suit the particular installation.
r .v. . . . . . ; . .:
Claims (27)
1. A static mixer for one or more fluids flowing in a pipe, the mixer comprising a flow divider element arranged to divide fluid flowing in a pipe into at least two separate streams flowing within the pipe, a first stream on one side of the pipe and a second stream on the other side of the pipe, characterized by a first flow diverter having a first flow diversion surface arranged transverse to the flow divider and arranged to deflect the first stream to rotate about an axis parallel to the general direction of flow in a first sense and a second flow diverter having a second flow diversion surface arranged to deflect the second stream to rotate about an axis parallel to the general direction of flow in a second, opposite sense, the first and second flow diversion surfaces being oriented at respective angles less than or equal to 90° relative to the flow divider element and the element and diverters being shaped so as to maintain movement of the flow through the mixer without introducing unnecessary turbulence.
2. A static mixer as claimed in claim 1, wherein the element includes a smoothly contoured surface leading to the part of the element which divides the flowing fluids.
3. A static mixer as claimed in claim 1 or claim 2, wherein the element includes a smoothly contoured surface which leads away from the part of the element which deflects two of the resulting streams so that those streams rotate in opposite senses.
4. A static mixer as claimed in claim 1, 2 or 3, wherein the part of the element which divides the flowing fluids into at least two streams within the pipe extends over a significant axial distance.
5. A static mixer as claimed in claim 1, 2 or 3, wherein the part of the element which divides the flowing fluids into at least two streams within the pipe extends over an axial distance equivalent to about a half to three-quarters of the diameter of the pipe.
6. A static mixer as claimed in claim 1, 2 or 3, wherein the part of the element which divides the flowing fluids into at least two streams within the pipe extends over an axial distance equivalent to about five-eighths of the diameter of the pipe.
7. A static mixer as claimed in any one of claims 1 to 6, wherein the part of the element which deflects two of the resulting streams so that those streams rotate in opposite senses extends over a significant axial distance.
8. A static mixer as claimed in any one of claims 1 to 7, wherein the part of the element which deflects two of the resulting streams so that those streams rotate in opposite senses extends over an axial distance equivalent to a half to three-quarters of the diameter of the pipe.
9. A static mixer as claimed in any one of claims 1 to 7, wherein the part of the element which deflects two of the resulting streams so that those streams rotate in opposite senses extends over an axial distance equivalent to about five-eighths of the diameter of the pipe.
10. A static mixer as claimed in any one of claims 1 to 9, wherein the surface of the element which faces downstream defines a substantial absence of cavities facing downstream.
11. A static mixer as claimed in any one of claims 1 to 10, wherein the surface of the element which faces upstream defines a substantial absence of cavities facing upstream.
12. A static mixer as claimed in any one of claims 1 to 11, wherein substantially the entire impingement surface of the element is at an angle of no greater than 85°.
13. A static mixer as claimed in claim 11, wherein substantially the entire impingement surface of the element is at an angle of no greater than 80° to the flow direction.
14. A static mixer as claimed in claim 11, wherein substantially the entire impingement surface of the element is at an angle of no greater than 70° to the flow direction.
15. A static mixer as claimed in any one of claims 1 to 14, wherein substantially the entire post impingement surface of the element is at an angle of no greater than 85° to the flow direction.
16. A static mixer as claimed in claim 15, wherein substantially the entire post impingement surface of the element is at an angle of no greater than 75° to the flow direction.
17. A static mixer as claimed in claim 15, wherein substantially the entire post impingement surface of the element is at an angle of no greater than 60° to the flow direction.
18. A static mixer as claimed in any one of claims 1 to 17, wherein the maximum angle of direction change of the flow surface of the element is 70°.
19. A static mixer as claimed in any one of claims 1 to 18, wherein the most upstream part of the element comprises a part which presents a rising slope from an inner wall of the pipe to a ridge and then presents a descending slope back to the inner wall of the pipe.
20. A static mixer as claimed in any one of claims 1 to 19, wherein the element comprises a central wall part which divides the pipe into two.
21. A static mixer as claimed in any one of claims 1 to 20, wherein the element comprises a pair of handed curved parts which direct the flow through an angle of 60° to 120°.
22. A static mixer as claimed in claim 21, wherein the element comprises a pair of handed curved parts which direct the flow through an angle of 80° to 100°.
23. A static mixer as claimed in claim 21, wherein the element comprises a pair of handed curved parts which direct the flow through an angle of about 90°.
24. A static mixer as claimed in any one of claims 1 to 23, wherein the element is produced in one or two pieces.
25. Apparatus for monitoring flow comprising a mixer as claimed in any one of claims 1 to 24 and means for measuring the pressure drop across the mixer.
26. Apparatus as claimed in claim 25, wherein the apparatus further includes means for measuring liquid hold-up after the mixer.
27. Apparatus as claimed in claim 26, wherein the means for measuring liquid hold-up comprises phase fraction or liquid fraction measurement instruments.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9419520.3 | 1994-09-28 | ||
| GB9419520A GB9419520D0 (en) | 1994-09-28 | 1994-09-28 | A mixer and apparatus for analysing fluid flow |
| PCT/GB1995/002294 WO1996009880A2 (en) | 1994-09-28 | 1995-09-27 | A mixer and apparatus for analysing fluid flow |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2201114A1 CA2201114A1 (en) | 1996-04-04 |
| CA2201114C true CA2201114C (en) | 2006-08-01 |
Family
ID=36764280
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002201114A Expired - Lifetime CA2201114C (en) | 1994-09-28 | 1995-09-27 | A mixer and apparatus for analysing fluid flow |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2201114C (en) |
-
1995
- 1995-09-27 CA CA002201114A patent/CA2201114C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| CA2201114A1 (en) | 1996-04-04 |
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