Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N9/00—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity
  • G01N9/36—Analysing materials by measuring the density or specific gravity, e.g. determining quantity of moisture
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N11/00—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
  • G01N11/10—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by moving a body within the material
  • G01N11/16—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by moving a body within the material by measuring damping effect upon oscillatory body
  • G01N11/162—Oscillations being torsional, e.g. produced by rotating bodies
  • G01N11/167—Sample holder oscillates, e.g. rotating crucible

Definitions

• the object of the invention relates to the technical field of the characterization of flow disturbances in the general sense, of a fluid inside a cylindrical pipe.
• the object of the invention finds a particularly advantageous application for allowing the detection or measurement of flow disturbances for a fluid, gaseous, liquid or multiphase, flowing in a pipeline, in particular underwater, placed at large, or even at very great depths.
• a first method which relies on the difference in the electrical properties of the constituents of the multiphase fluid which flows inside the pipeline. It is thus possible to carry out measurements of the capacity, inductance or conductivity of the fluid, with a view to detecting the instability of the multiphase flow and, in particular, the appearance of liquid plugs, insofar as the dielectric characteristics between the gas and liquid pockets are very different.
• a device based on the technique of impedance imaging which consists in studying the response of the fluid to an alternating low voltage electrical excitation.
• Such a system comprises an excitation electrode sending a current and a series of measurement electrodes making it possible to know the distribution of the collected currents. Such a distribution reflects the way in which the current lines pass through the liquid and bypass the gas which is less good conductor than the liquid. It is thus possible to obtain a true flow map.
• the object of the invention therefore aims to satisfy this need by proposing a non-intrusive method for characterizing the flow disturbances of a fluid inside a cylindrical pipe.
• the method consists in determining the flow disturbances, to be used as the first indicator, the variation in fluid pressure: - by placing around the pipe, at least one clamp provided with at least one deformation sensor sensitive to the deformations that the pipe undergoes following the variations in fluid pressure,
• Another characteristic of the invention aims to propose a non-intrusive device for characterizing the flow disturbances of a fluid inside a cylindrical pipe.
• the device comprises at least one system for measuring the pressure of the fluid comprising:
• At least one clamping collar provided with at least one strain sensor sensitive to the strains that the pipeline undergoes following the variations in fluid pressure
• Fig. 1 is a schematic sectional view of an exemplary implementation of a device according to the invention.
• FIG. 2A, 3A and 4A are cross-sectional views of the device illustrated in FIG. 1 and showing various measurement systems according to the invention.
• Figs. 2B, 3B and 4B are curves illustrating the measurements carried out by the systems illustrated respectively in FIGS. 2 A, 3 A and 4 A.
• Fig. 1 represents a device 1 for characterizing the flow disturbances of a fluid inside a cylindrical transport pipe 2, with a longitudinal axis X.
• the fluid is of any kind, for example liquid, gaseous or multiphase, such as a petroleum fluid for example.
• Line 2 can be considered, for example, as horizontal but can naturally have any kind of orientation, such as vertical.
• This pipe 2 can be made of various materials such as steel and be installed in the open air or be submerged at great, even very great depth.
• the device 1 is suitable for characterizing a disturbance in the flow of the fluid, that is to say for example a change in pressure, flow rate, homogeneity, etc.
• the device 1 comprises at least one system 3 for measuring the pressure of the fluid flowing inside the pipe 2.
• the measurement system 3 comprises at least one clamp 4 mounted locally outside line 2, in a measurement zone Z ⁇ .
• the clamping collar 4 is equipped with clamping means 5 of all types, adapted to allow the collar 4 to match the external shape of the pipe 2.
• the clamping means 5 also make it possible to lock, in a determined position, the collar around the outer wall of the pipe 2.
• the clamping means 5 have an adjustable character making it possible to adjust the pressure difference appearing at the location of the collar between the inside and the outside of the pipe 2 The values of the detected pressure variations can thus be adjusted.
• the clamp 4 is fitted with at least one, and in the example illustrated in FIG. 2A, two deformation sensors 6 which are each sensitive to the deformations which the pipe 2 undergoes following the variations in the pressure of the fluid.
• each deformation sensor 6 is of the strain gauge, resistive or optical fiber type.
• Each deformation sensor 6 can also be of the fiber optic type wound around the pipe 2.
• the deformations undergone by the wall of the pipe 2 reflect the action of the fluid inside the pipe and therefore the variations in pressure. fluid. It thus appears that the elongation measured by the sensor on the external generator of the pipe 2 is proportional to the diameter of the pipe multiplied by the difference between the pressure inside and outside the pipe, divided by twice the thickness of the pipe wall 2.
• the deformation sensor (s) 6 are connected by a link 7 to measuring and processing means 8 making it possible to determine the variations in pressure of the fluid inside the pipe 2 from measurements of variations in deformation detected by each deformation sensor 6.
• FIG. 2B gives by way of example, the variations in deformations recorded by a deformation sensor 6, as a function of time t.
• the device 1 also includes a system 10 for measuring the variations in heat exchange occurring between the fluid and the pipe 2.
• a measurement system 10 includes at least one clamp 11 mounted locally around the pipe 2 in the measurement zone Zi.
• the clamp 11 is fitted with clamping means 12 designed to allow the clamp 11 to best match the external shape of the pipe 2.
• the clamping means 12 designed to allow the clamp 11 to best match the external shape of the pipe 2.
• the clamp 11 is equipped with at least one and preferably with a series of sensors 13 for measuring the heat flow, each sensitive to the heat exchange occurring between the fluid and the pipe 2.
• Each measurement sensor is equipped with at least one and preferably with a series of sensors 13 for measuring the heat flow, each sensitive to the heat exchange occurring between the fluid and the pipe 2.
• each heat flow sensor 13 of the heat flow is mounted to access the heat exchange (i.e. in Watts / cm) between the pipe 2 and the fluid circulating inside the pipe.
• each heat flow sensor 13 is constituted by a flow meter mounted on the collar 11 constituted by a flexible strip, such as a neoprene strip.
• the clamping collar 11 can also integrate a temperature probe of the external surface of the pipe 2.
• Each heat flow measurement sensor 13 is connected via a link 14 of all types, to measuring and processing means 15 making it possible to determine the variations in the heat flow from the measurements of variations in heat exchange detected by each heat flow sensor 13.
• FIG. 3B illustrates the variations in thermal flux measured by a flux sensor 13, over time t.
• the device 1 also comprises a system 20 for measuring noise and vibrations generated by the flow of the fluid, such as friction of the fluid on the wall of the pipe or water hammer.
• a noise and vibration measurement system 20 comprises at least one clamp 21 mounted externally locally on the pipe 2 in the measurement zone Zi.
• the clamping collar 21 is provided with clamping means 22 adapted to allow the collar 21 to match the shape of the outer wall of the pipe 2.
• the clamping means 22 also make it possible to lock in a determined position, the collar around of the external wall of the pipe 2.
• the clamp 22 is fitted with at least one vibration sensor 23 sensitive to noise and vibrations produced by the flow of the fluid inside the pipe 2.
• each vibration sensor 23 consists of an accelerometer of the piezoelectric or optical fiber type or of piezoelectric films (PVDF, copolymer, PZT, etc.).
• Each vibration sensor 23 is connected by means of a link 25, to measurement and processing means 26 making it possible to determine the variations in noise and vibrations produced by the flow of the fluid inside the pipe. from the vibration measurements detected by each vibration sensor 23.
• FIG. 4B illustrates, by way of example, the evolution over time t, of the variation of the vibrations detected by a vibration sensor 23.
• the method according to the invention consists in characterizing the disturbances d flow using at least a first indicator, namely the pressure variation of the fluid flowing inside the pipe 2.
• a system 3 for measuring the pressure of the fluid is installed on said pipe in a measurement zone Zi.
• a measurement system 3 has the advantage of being non-invasive or non-intrusive, since it only requires the mounting of a collar around the pipe 2.
• Such a system 3 makes it possible to measure a variation in pressure of the conducting fluid to deduce a disturbance in the flow of the fluid.
• a reference model comprising three successive phases, namely:
• the method consists in characterizing the flow disturbances by also using, if necessary, a second indicator, namely the variations in heat exchange between the fluid and the pipe 2.
• a system 10 for measuring variations in heat exchange between the fluid and the pipe 2 is installed in the measurement zone Zi.
• Such a measurement system 10 also has the advantage of being non-invasive since it requires the mounting of a collar around the pipe 2. Such a system 10 makes it possible to measure a variation in heat exchange leading to deduce a disturbance in the flow of the fluid. According to an advantageous characteristic of embodiment, provision is made to compare, using the measurement and processing means
• the variations in heat exchange measured with at least one reference model of variation in heat exchange making it possible to characterize a type of flow disturbance.
• a reference model comprising three successive phases, namely:
• the method according to the invention consists in characterizing the flow disturbances by using a third indicator, namely the noises and vibrations produced by the flow of the fluid inside the pipe 2.
• a noise and vibration measurement system 20 is installed in the measurement zone Zj. Such a measuring system 20 has the advantage of being non-invasive since it allows the mounting of a collar around the pipe 2.
• Such a system 20 makes it possible to measure the noises and vibrations caused by the flow of the conducting fluid to deduce a disturbance in the flow of the fluid.
• a reference model for variation in noise and vibration making it possible to characterize a type flow disturbance.
• it can be defined to characterize the presence of a liquid plug, a reference model comprising a phase P " ⁇ of a given duration during which the measured values exceed a determined threshold. This phase P" ⁇ corresponds to the passage of a liquid stopper.
• the characterization of a type of flow disturbance is carried out with the implementation of the first indicator associated or not with the second and / or the third indicator.
• the measurements of pressure variation, variation of heat flow and variation of noise and vibrations are carried out simultaneously to allow, after comparison with the respective reference models, to verify the type of flow disturbance.
• the appearance of a liquid plug detected by the pressure measurement system 3 can be confirmed by the information given by the flow 10 and / or noise and vibration 20 measurement systems.
• a second measurement zone Z 2 distant from the first Zi, along the longitudinal axis X.
• this second measurement zone Z 2 there are installed cable ties provided deformation and / or heat flow and / or vibration sensors belonging to systems for measuring pressure 3, heat flow 10 and noise and vibration 20 respectively. measurements carried out by the same type of sensors belonging to the two zones are intercorrelated, with a view to obtaining the propagation speed of the disturbance as well as its dimensional characteristics.

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• General Health & Medical Sciences (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Measuring Volume Flow (AREA)
• Indicating Or Recording The Presence, Absence, Or Direction Of Movement (AREA)
• Geophysics And Detection Of Objects (AREA)

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• 2000
  • 2000-02-11 FR FR0001755A patent/FR2805042B1/fr not_active Expired - Lifetime
• 2001
  • 2001-02-08 AU AU2001235629A patent/AU2001235629A1/en not_active Abandoned
  • 2001-02-08 US US10/181,924 patent/US20030010126A1/en not_active Abandoned
  • 2001-02-08 EP EP01907731A patent/EP1254359A1/de not_active Withdrawn
  • 2001-02-08 CA CA002399615A patent/CA2399615A1/fr not_active Abandoned
  • 2001-02-08 BR BR0108201-9A patent/BR0108201A/pt not_active IP Right Cessation
  • 2001-02-08 WO PCT/FR2001/000365 patent/WO2001059427A1/fr active Application Filing
• 2002
  • 2002-07-02 NO NO20023205A patent/NO319683B1/no not_active IP Right Cessation

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