An apparatus to measure at least a pressurized fluid property and a related method

Abstract

The apparatus comprises a cylinder (22) configured to receive exclusively gas and / or liquid and a fluid distributor configured to transport fluid to be measured under pressure in the cylinder (22). It comprises a X-ray source (30), configured to illuminate the cylinder (22) and a detector (32), placed opposite the X-ray source (30) the cylinder (22) being interposed between the source (30) and the detector (32) The X-ray beam (92) from the source (30) is configured to illuminate a volume of the cylinder (22) without relative movement between the X-ray source (30) and the cylinder (22). The detector (32) comprises a plurality of sensing areas (110) configured to detect X photons arising from different points in the cylinder (22) The apparatus comprises a radiation protection enclosure (20), defining a inner confinement space (40) containing the cylinder (22), the fluid distributor, the X-ray source (30) and the detector (32).

Description

[0001] An apparatus to measure at least a pressurized fluid property and a related method

[0002] The present invention concerns an apparatus to measure at least a pressurized fluid property, the fluid comprising gas and / or liquid, the apparatus comprising :

[0003] - at least a pressure-resisting cylinder, defining a hollow inner volume configured to receive exclusively gas and / or liquid ;

[0004] - a fluid distributor, configured to transport fluid to be measured under pressure in the inner volume of the pressure-resisting cylinder.

[0005] Such an apparatus is in particular intended to visualize a location and content of the phases of a multiphase fluid under pressure, to assess and quantify the phase composition of the fluid at different locations in the sample.

[0006] The apparatus is especially adapted in case the fluid has a complex composition, for example when composed of three phases like oil, water and gas and / or in case the fluid is an emulsion.

[0007] The apparatus also aims at determining complex properties of the fluid under pressure, such as dew point, bubble point and / or interfacial tension between two fluids.

[0008] The determination of the properties of a fluid under pressure, in particular at pressures above several bara, is a complex task, in particular if the fluid comprises several phases.

[0009] In some instances, a fluid sample is collected and transported under pressure in a pressurized cylinder made of metal. The fluid sample is kept under pressure and sometimes in temperature in the pressurized cylinder.

[0010] If the nature or / and the quantity of the fluid can be approximated, characterizing measurements can be carried out under pressure directly in the pressurized cylinder.

[0011] However, the cylinder being opaque, it is impossible to visualize the fluid while it is characterized. An alternate solution is transferring the fluid in a cylinder having at least a pressure-resisting window which allows a direct visualization of the fluid.

[0012] Such a cell is very often limited to low pressures. When used at higher pressures, it can lead to safety issues, since the window may crack or even burst after some time.

[0013] In other instances, determining and quantifying a phase composition of a multiphase fluid under pressure is very valuable to assess how the fluid behaves at a working pressure, for example a pressure under which the fluid resides at the bottom of a well or in a reservoir.

[0014] For example when the fluid is sampled at the outlet of a core flooding experiment, the nature, the number of phases and the phase composition of the sampled fluid is generally unknown. In order to determine and quantify the composition, the fluid is depressurized and transferred in a measurement apparatus at atmospheric pressure. Once the measurement has been made on the depressurized fluid, mathematical models are used to evaluate the fluid properties under pressure.

[0015] There is thus no direct measurement of the fluid properties at the desired pressure and flaws may appear due to the complexity of the fluid, whose behavior at different pressures may not be easy to model.

[0016] One aim of the invention is thus to obtain a measuring apparatus which is able to precisely measure at least a property of a pressurized fluid comprising gas or / and liquid, the device being accurate and very safe to use.

[0017] To this aim, the subject matter of the invention is an apparatus of the above- mentioned type, characterized by:

[0018] - a X-ray source, configured to illuminate the inner volume with a beam of X photons, the beam extending along an illumination axis ;

[0019] - a detector, placed opposite the X-ray source along the illumination axis, the inner volume of the pressure-resisting cylinder being interposed between the X-ray source and the detector, the beam being configured to illuminate at least a volume of the inner volume without relative movement between the X-ray source and the inner volume, the detector comprising a plurality of sensing areas configured to detect X photons arising from different points in the inner volume ;

[0020] - a radiation protection enclosure, defining a inner confinement space containing the or each pressure-resisting cylinder, the fluid distributor, the X-ray source and the detector.

[0021] The apparatus according to the invention may comprise one or more of the following feature(s), taken solely or according to any technical feasible combination:

[0022] - the pressure-resisting cylinder is opaque to visible light ; the pressure-resisting cylinder is made of a material transparent to X-rays ; the pressure-resisting cylinder comprises a cylinder body defining the inner volume and an inner liner tightly positioned within the cylinder body, the cylinder body being in particular made of a composite material comprising reinforcing fibers, the inner liner being preferably composed of a reinforcing polymer, in particular poly ether ether ketone or a metallic liner ; it comprises a plunger, movable within the inner volume of the pressure-resisting cylinder and an actuator to move the plunger in the inner volume ;

[0023] - it comprises a pressure sensor configured to sense a fluid pressure within the inner volume, the actuator being configured to move the plunger based on a fluid pressure sensed by the pressure sensor ; - the X-ray source comprises a controller, configured to control the energy of the X photons of the beam to a maximum energy, the maximum energy being lower than 90kV, in particular being comprised 60 kV and 120 kV ;

[0024] - the pressurized fluid comprises a liquid phase and a gas phase, preferentially at least an oil phase, a water phase and a gas phase, the apparatus comprising an analyzer configured to determine a phase composition of the fluid at a plurality of positions in the inner volume based on signals simultaneously detected by sensing areas of the detector ; the distributor comprises at least an inlet to inject fluid into the inner volume, in particular comprising an inlet / outlet configured to inject fluid in the inner volume and to recover fluid from the inner volume ;

[0025] - the distributor comprises at least an outlet, preferentially at least two outlets separate from the inlet to recover fluid from the inner volume, in particular to recover different phases of fluid in the inner volume ;

[0026] - it comprises a measuring fluid injection pipe to create a measuring fluid droplet in a fluid received in the inner volume and / or a detachable body, in particular a detachable ball, configured to be dropped in the fluid received in the inner volume ;

[0027] - it comprises at least two pressure-resisting cylinders, each defining an inner volume configured to receive exclusively gas and / or liquid.

[0028] The subject matter of the invention is also a method to measure a pressurized fluid property, comprising:

[0029] - providing an apparatus as defined above ;

[0030] - transporting fluid to be measured under pressure in the inner volume of the pressureresisting cylinder via the fluid distributor, the inner volume only containing gas and / or liquid;

[0031] - illuminating the inner volume with a beam of X photons produced by the X-ray source, the beam extending along a first illumination axis, at least a volume of the inner volume being illuminated without relative movement between the X-ray source and the inner volume ;

[0032] - detecting X photons arising from different points in the inner volume at the plurality of sensing areas of the first detector, placed opposite the first X-ray source along the first illumination axis.

[0033] The method according to the invention may comprise one or more of the following feature(s), taken solely, or according to any technical feasible combination:

[0034] - the method comprises calculating a local property of the fluid at a plurality of positions in the inner volume in particular, determining a phase composition of the fluid at a plurality of positions in the inner volume with an analyzer of the apparatus; the apparatus comprises a movable plunger, movable in the cylinder to vary the pressure within the cylinder, and an actuator to move the plunger, the method comprising moving the plunger to modify the pressure of the fluid in the inner volume, in particular to determine a bubble point or / and a dew point of the fluid;

[0035] - the method comprises creating a measuring fluid droplet in the fluid received in the inner volume via a measuring fluid injection pipe to determine an interfacial tension between the measuring fluid and the pressurized fluid and / or dropping a detachable body, in particular a detachable ball, into the fluid received in the inner volume to determine a viscosity of the pressurized fluid.

[0036] The invention will be better understood, based on the following description, made in reference to the following drawings, given solely as an example, in which:

[0037] - figure 1 is a side sectional view of a measuring apparatus according to the invention;

[0038] - figure 2 is a top sectional view of the apparatus of figure 1 , comprising two parallel cylinders to receive and measure fluid under pressure;

[0039] - figure 3 is a view of an image obtained with the apparatus according to the invention, in which the different phases of a multiphase fluid are visible and can be quantified;

[0040] - figure 4 is a schematic sectional vertical view of two parallel cylinders receiving fluid to be measured, each cylinder being equipped with a plunger actuated with an actuator;

[0041] - figure 5 is a view similar to figure 4, illustrating a cylinder connected to a distributor allowing sampling of a gas phase and of a liquid phase to be reused in the measurement ;

[0042] - figure 6 is a view similar to figure 5, in which the cylinder is equipped with a capillary tube to measure surface tension of a fluid under pressure ; and

[0043] - figure 7 is a view similar to figure 5, in which the cylinder is equipped with a detachable ball to measure viscosity of a fluid under pressure.

[0044] A first apparatus 10 intended to measure a pressurized fluid property is illustrated in figures 1 to 4.

[0045] The fluid to be measured is for example a multiphase fluid comprising a liquid phase and a gas phase, in particular a fluid comprising a gas phase, an oil phase and a water phase. The fluid is in particular a multiphase hydrocarbonaceous fluid comprising oil and gas.

[0046] The fluid property to be detected by the apparatus is for example the phase composition and / or phase localization in a sample of fluid 12 which is maintained under pressure. The pressure to which the fluid 12 is maintained is comprised generally between 0.1 bara and 1000 bara.

[0047] The fluid 12 is also advantageously maintained in temperature, for example at a temperature ranging from 20°C to 200°C.

[0048] As will be seen below, other fluid properties such as dew point, bubble point, surface tension and / or viscosity can be also evaluated under pressure with the apparatus 10 according to the invention.

[0049] As shown in figure 1 to 4, the apparatus 10 comprises a radiation protection enclosure 20, and within the enclosure 20, at least a pressure-resisting cylinder 22, in particular a plurality of pressure-resisting cylinders 22, as shown in figures 2 and 4.

[0050] The apparatus 10 comprises, for each cylinder 22, a plunger 24 (visible in figures 3 and 4), movable within the cylinder 22 to set a pressure of the fluid 12 in the cylinder 22, and an actuator 26 to move the plunger 24 within the cylinder 22.

[0051] The apparatus advantageously comprises a pressure sensor 28 to measure the pressure of the fluid within the cylinder 22 and to move the plunger accordingly. It comprises a temperature sensor 29 to measure a fluid temperature within the cylinder 22 and a temperature adjuster 29A, to control the fluid temperature within the cylinder 22 based on the temperature measurement carried out by the temperature sensor 29.

[0052] The apparatus 10 further comprises a fluid distributor 23, shown in figure 4, to inject fluid 12 within the cylinder 22 and / or to recover fluid 12 from the cylinder 22.

[0053] As shown in figures 1 and 2, the apparatus 10 also comprises an X-ray source 30 and a detector 32, both located in the enclosure 20. The detector 32 is located opposite the X- ray source 30, with the or each pressure-resisting cylinder 22 being interposed between the X-ray source 30 and the detector 32 within the enclosure 20.

[0054] The apparatus 10 further has a control unit 34 to control the X-ray source 30 and to control the movement of the plunger 24 via the actuator 26, based on a pressure measurement obtained with the pressure sensor 28.

[0055] The apparatus 10 further comprises an analyzer 36, connected to the detector 32 to analyze data recovered at the detector 32 and determine at least a fluid property based on the recovered data.

[0056] In the apparatus 10, the cylinder 22, the X-ray source 30 and the detector 32 are fixedly mounted in the enclosure 20, without relative movement between them in particular without rotation between them.

[0057] As visible in figure 1 , the enclosure 20 defines an inner confinement space 40 configured to receive the or each pressure-resisting cylinder 22, the plunger 24 and the actuator 26, and all the measuring equipment such as the pressure and temperature sensors 28, 29, the X-ray source 30, the detector 32. The control unit 34 and the analyzer 36 are generally located outside of the inner confinement space 40.

[0058] The enclosure 20 comprises outside walls which all comprise radioactivity emission absorbing material such as metal, in particular lead.

[0059] In this example, the enclosure 20 comprises a lower floor 42, a lateral wall 44, equipped with at least one door to access the inner confinement space 40, and a ceiling 46.

[0060] The enclosure 20 is for example mounted on rollers or has other displacement means to be moved around an experimentation space. Thus, the X-ray source 30, the detector 32, and the or each pressure-resisting cylinder 22 are configured to be moved jointly with the enclosure 20.

[0061] The inner confinement space 40 has a volume for example greater than 0.1 m3and generally comprised between 0.4 m3and 1 .0 m3.

[0062] The enclosure 20 confines X-ray radiations within the inner confinement space 40. The dose flux at the external surfaces of the walls 43 of the inner confinement space 40 is smaller than 100 mSv per month, in particular smaller than 80 mSv per month.

[0063] In the example of figure 2, two cylinders 22 are provided side to side in the inner confinement space 40. The two cylinders 22 are mounted parallel to each other at the same height.

[0064] Each pressure-resisting cylinder 22 defines an inner cylindrical volume 50 to receive fluid under pressure to be measured.

[0065] It comprises a cylinder body 52, delimiting inwardly the inner cylindrical volume 50 and advantageously a reinforcing liner 54, arranged inside the cylinder body 52 to provide sealing against pressure applying from the inner cylindrical volume 50 onto the cylinder body 52.

[0066] The inner cylindrical volume 50 is hollow, and is empty in the absence of the fluid to be measured. In particular, the inner cylindrical volume 50 is devoid of solid material, in particular of porous solid material. It defines a continuous cylindrical volume available to receive fluid 12 under pressure.

[0067] In the example of figure 3, the cylinder body 52 comprises a cylindrical sleeve 56 to provide sealing for the fluid 12 contained within the cylindrical volume 50, and a cap 58, closing the inner cylindrical volume 50 at an upper end of the cylindrical sleeve 56.

[0068] The cylinder body 52 extends along a longitudinal axis A-A'. The longitudinal axis A- A’ is held vertical in the inner confinement space 40 of the enclosure 20.

[0069] The cylindrical sleeve 56 is for example made of a composite material such as a polymer reinforced with a reinforcing fiber, such as carbon fiber or glass fiber. Its attenuation to X-rays is low, generally less than the attenuation provided by steel. The cap 58 is for example made of titanium or steel. In a variant, the cap 58 is replaced with a transverse wall integral with the cylindrical sleeve 56.

[0070] The cylindrical sleeve 56 defines a lower axial opening 60, through which the plunger 24 is inserted to close the inner cylindrical volume 50. The fluid 12 to be measured is thus confined within the inner cylindrical volume 50 and able to be pressurized by the plunger 24.

[0071] The liner 54 is arranged inside the cylinder body 52, in contact with the cylinder body 52. It is for example made of a material which provides a low attenuation to X-rays, in particular an attenuation smaller than the attenuation provided by steel.

[0072] The liner 54 is for example made of a highly resisting polymer such as an organic thermoplastic polymer of the polyaryl ether ketone family, such as polyether ether ketone (PEEK).

[0073] The inner cylindrical volume 50 is generally comprised between 1 cm3and 1000 cm3, generally between 1 cm3and 100 cm3, depending on the position of the plunger 24.

[0074] The plunger 24 tightly seals the inner cylindrical volume 50 in a downward direction. It is mounted mobile in translation within the cylinder body 52 along the longitudinal axis A- A' of the cylinder body 52. It is for example made of titanium or steel.

[0075] The actuator 26 is here made of a syringe pump. It comprises a stem 70 connected at its free end to the plunger 24, to move the plunger 24 along the axis A-A'. The actuator further comprises a motor 72, for example a step motor, configured to displace the stem 70 along the axis A-A' in two directions.

[0076] In the example of figure 1 , the stem 70 and the motor 72 are both contained within the inner confinement space 40 of the enclosure 20. The motor 72 is connected to the control unit 34, to be piloted by the control unit 34.

[0077] The pressure sensor 28 has a probe located in the inner cylindrical volume 50 to measure the pressure inside the inner cylindrical volume 50. It is connected to the control unit 34 and potentially to the analyzer 36 to provide a pressure measurement value within the inner cylindrical volume 50 at successive measurement times.

[0078] Similarly, the temperature sensor 29 has a probe located in the inner cylindrical volume 50 to measure the temperature inside the inner cylindrical volume 50. It is connected to the control unit 34 and potentially to the analyzer 36 to provide a temperature measurement value within the inner cylindrical volume 50 at successive measurement times.

[0079] In the example of figure 4, the fluid distributor 23 comprises a single fluid inlet / outlet 74, to allow injection of fluid in the inner cylindrical volume 50 and / or removal of fluid 12 from the inner cylindrical volume 50. The fluid distributor 23 advantageously comprises at least a control valve 76 to regulate the fluid flow 12 entering the inner cylindrical volume 50 or recovered from the inner cylindrical volume 50.

[0080] The inlet / outlet 74 is located here at the top of the inner cylindrical volume 50. Movement of the plunger 24 away from the inlet 74 allows fluid 12 to be introduced into the inner cylindrical volume 50, whereas movement of the plunger 24 towards the inlet 74 allows fluid to be recovered from the inner cylindrical volume 50.

[0081] In a variant, shown in figure 5, the fluid distributor comprises at least a fluid inlet 74, which conveys fluid to the inner cylindrical volume 50, and at least a separate fluid outlet 78, 80 to recover fluid 12 from the inner cylindrical volume 50.

[0082] In the example of figure 5, the distributor 23 comprises an upper fluid outlet 78, emerging at the top of the inner cylindrical volume 50 to recover a gas phase 14 from the inner cylindrical volume 50. It further comprises a lower outlet 80, located at the bottom of the inner cylindrical volume 50, for example through the plunger 24, to recover liquid contained in the inner cylindrical volume 50.

[0083] The temperature adjuster 29A for example comprises a heating sheet located around the cylinder 22. The temperature of the inner volume 50 is for example maintained at a target temperature between 20°C and 200°C.

[0084] The X-ray source 30 comprises a X-ray generator 90 (shown in figure 1 ) configured to produce a beam 92 of X photons to illuminate the fluid 12 contained into the enclosure 20, along an illumination axis B-B’, which is here horizontal.

[0085] The X-ray source 30 further comprises a tension and current controller 94 to supply electrical power to the generator 90 and thus, to control the energy of the X photons emitted in the respective beam 92

[0086] The beam 92 is configured to illuminate at least a volume of the fluid 12 contained in the inner cylindrical volume 50 and preferably the whole fluid 12 contained in the inner cylindrical volume 50, without relative movement between the X-ray source 30 and the fluid 12.

[0087] The term “at least a volume of the fluid” mean that the illumination is not punctual. The volume of the fluid 12 illuminated by the beam 92 is generally greater than 0.1 cm3.

[0088] The horizontal aperture angle a and the vertical aperture angle R> of the beam 92 are set so that the whole zone of interest including the fluid 12 is irradiated without any relative movement. These angles a, R> are limited to that zone to reduce at maximum scattering radiations.

[0089] The power of emission is defined here by the voltage applied to the generator 90. This high voltage is for example comprised between 60 kV and 120 kV, in particular between 65 kV and 85 kV. The generator 90 is for example an integral assembly made of one block such as a generator marketed under the reference GXC80 by XRIS

[0090] A generator 90 of this type generally comprises an integral air cooler.

[0091] In a variant, the generator 90 is made of separate elements such as a generator marketed under the reference GXC130 by XRIS

[0092] A generator 90 of this type comprises a X-ray tube 96 (e.g. a glass tube or a ceramic tube) and a temperature controller 98 configured to control the temperature of the X-ray tube 96.

[0093] The X-ray tube 96 comprises a metal filament, notably a tungsten filament and is constantly heated so that the electron flux is constant and stable.

[0094] The temperature controller 98 comprises for example a cooling fluid configured to circulate in a double wall located around the X-ray tube 96, or a ventilator to ensure air circulation.

[0095] The temperature of the tube 96 is for example maintained at a target temperature between 25°C and 35°C.

[0096] The tension and current controller 94 is configured to produce a stabilized current and tension to supply the generator 90. Advantageously, during more than 1 hour, in particular during several hours, the variation of tension is smaller than 0.1 % (in kV) and the variation in intensity is smaller than 1 % (in mA).

[0097] The X-ray source 30 is configured to emit the X-ray beam 92 towards the cylinder 22 and the detector 32.

[0098] In the embodiment shown in figure 1 , the X-ray source 30 is preferentially equipped with a collimator 100 for controlling the emission of X-rays into the confinement space 40 towards the cylinder 22.

[0099] The X-ray source 30 can remain permanently active. By “permanently active”, it is meant the X-ray source 30 is configured to continuously emit a photon flux during the time of at least one measurement, preferentially of several measurements of the fluid 12. The source for example remains active more than one day, preferentially more than one month. It shoots photons at any time when it is active.

[0100] In reference to figure 1 , the detector 32 comprises an array of sensing areas 110 configured to selectively detect X-rays arising from the corresponding X-ray source 30 potentially having passed through the fluid 12.

[0101] Advantageously, the detector 32 comprises a flat panel 112 carrying an array of sensing areas 1 10 defining pixels in the flat panel 1 12. The flat panel 112 is for example a planar amorphous silicon flat panel, marketed under the name DEREO WA. The detector advantageously comprises a temperature control unit 1 12A (see figure 2) controlling the temperature of the flat panel 1 12.

[0102] Each pixel formed by a sensing area 110 is configured to selectively receive a number of X-photons arising from the X-ray source 30, corresponding selectively to a particular position in a projection of the fluid 12 in a vertical plane perpendicular to the illumination axis B-B’ or in alternative, to a position outside of the fluid 12.

[0103] At any measurement time, the sensing area 1 10 is configured to sense the number of X-photons received during a sampling interval for example smaller than 15 s, generally around 10 s and potentially comprised between 0.5 s and 10 s.

[0104] The number of X-photons received by the sensing area 1 10 is sensed data representative of the absorbance of the signal at the position detected by the sensing area 110.

[0105] The number of X-photons provides a level of grey in a radiographic image 113 (see figure 3) of the beam 92 after its passage through the fluid 12, or through the confinement space 40 away from the fluid 12.

[0106] The image 1 13 representing the level of gray at different positions in the fluid 12, in a plane perpendicular to the illumination axis B-B’, can be obtained at successive given measurement times by the detector 30, based on the signals produced by the sensing areas 110 of the detector 32.

[0107] In the region of the image 1 13, corresponding to X photons having passed through the fluid 12, the pixel is representative of the absorbance of the X-ray beam 92 having passed through the fluid 12 at the corresponding position in a projection of the fluid 12 in a respective vertical plane.

[0108] The analyzer 26 comprises a calculator 120 having a processor 122 and a memory 124, and a man / machine interface 126.

[0109] The memory 124 contains software applications which can be executed in the processor 122. Among the software applications, the memory 124 contains at least one software module configured to receive, at the measurement time, a signal representative of the number of photons measured by each sensing area 1 10.

[0110] The memory 124 further contains a software module configured to determine at least a property of the fluid at a particular position in the fluid 12. The property is for example an absorbance of the fluid at the particular position, or / and a phase composition of the fluid at the particular position. In particular, the software module is configured to detect interfaces between phases, and to determine the number of different phases and quantify the quantities of the different phases.

[0111] The calculation is based on the sensed signal produced by the sensing areas 110. The memory 124 also contains a software module configured to display, on the man / machine interface 126, the image 113 in grey levels at a given measurement time and / or a representation of the fluid property at the position of the fluid 12 corresponding to a sensing area 1 10, at a given measurement time.

[0112] In some cases, when successive measurements of the whole fluid 12 are carried out, the software module is also configured to display a curve of the evolution of the fluid property along time at a particular position in the fluid 12.

[0113] A method of measuring a local property of a pressurized fluid 12 made of gas and / or liquid in the apparatus 10 according to the invention will now be described.

[0114] In a first example, the method is described in the determination of a phase composition of a fluid 12 containing several phases, including at least a gas phase 14 and at least a liquid phase 16, 18, in particular several liquid phases 16, 18.

[0115] The method is for example carried out to characterize the fluid composition, in particular the volumes of gas, water and oil, of a fluid under pressure emerging from a core flooding experiment of a porous sample, after flooding the porous sample in a core flooding device 140 connected to the apparatus 10 according to the invention.

[0116] The core flooding device 140 is for example a device disclosed in WO 2016 / 087890 or WO 2022 / 171316.

[0117] As shown in figure 4, the device 140 is connected to the distributor 23 of at least two cylinders 22 of the apparatus 10 of the invention.

[0118] The fluid under pressure, at a pressure comprised between 1 bars and 1000 bars and at a temperature comprised between 20°C and 200°C is transported from the device 140 to the fluid distributor 23 of a first pressure-resisting cylinder 22.

[0119] The valve 76 is opened and the plunger 24 is gradually retracted from a position away from the cap 58 to increase the inner cylindrical volume 50 and receive the fluid 12.

[0120] The pressure is measured by the pressure sensor 28, and the actuator 26 is controlled by the control unit 34 to move the plunger 24 via the stem 70 to maintain the pressure inside the inner cylindrical volume 50 to a predetermined pressure. The predetermined pressure for example corresponds to the pressure of the fluid exiting from the device 140. The fluid 12 thus remains in the same pressure conditions as in the device 140.

[0121] The beam 92 from the source 30 illuminates the pressure-resisting cylinder 22 and the inner cylindrical volume 50 contained in the pressure-resisting cylinder 22.

[0122] The detector 32 is then activated, at each measurement time, to measure, at each sensing area 1 10, a signal representative of the number of counts of X photons having being transmitted through the fluid 12. As shown in figure 3, an image 1 13 is created with pixels corresponding to a particular position in the fluid.

[0123] All the positions which have been illuminated in the fluid 12 are measured simultaneously, which allows building a map of fluid properties in the inner cylindrical volume 50 at each measurement time. In this example, the different phases 14, 16, 18 of the fluid 12 appear distinct from one another and each presents an absorbance level which is characteristic of the specific phase 14, 16, 18.

[0124] The analyzer 36 is then activated to determine the volume of each phase 14, 16, 18 in the sample 12 and thus the phase composition of the sample 12, at the pressure at which it is controlled by the plunger 24 position.

[0125] When another fluid sample 12 has to be admitted into the apparatus 10, the device 140 is connected to the fluid distributor 23 of another pressure-resisting cylinder 22 to carry out the same measurement as described above. In the meantime, the inner cylindrical volume 50 of the previous pressure-resisting cylinder 22 is purged by moving the plunger 24 towards the inlet / outlet 74 of the cylinder body 52.

[0126] Thanks to the apparatus 10 according to the invention, it is thus possible to measure a fluid 12 property when the fluid is pressurized and maintained in temperature.

[0127] The pressure-resisting cylinder 22 being made of very resisting material, it provides a strong resistance to pressure and temperature. Even if the material is opaque to visible light (between 400 nm and 800 nm), the use of an X-ray source 30 coupled to a detector 32 within a radiation protection enclosure 20 allows a safe and accurate determination of the content of the inner cylindrical volume 50. The apparatus 10 makes it possible to image and quantify different phases 14, 16, 18 within the inner cylindrical volume 50 at the temperature and pressure at which the fluid 12 is maintained.

[0128] In a variant (not shown), a monophasic fluid, for example a liquid, is injected at a given pressure into the inner cylindrical volume 50. The pressure is then modified by actuating the plunger 24 with the actuator 26. The pressure value measured by the pressure sensor 28 is controlled to determine a pressure at which a phase change occurs into the monophasic fluid, for example the apparition of a new phase.

[0129] For example, the monophasic fluid injected in the inner cylindrical volume 50 is a liquid. The pressure of the inner cylindrical volume 50 is progressively decreased by moving the plunger 24 away from the inlet 74. At regular measurement times, images 1 13 of the fluid are taken to detect the formation of bubbles of gas phase within the liquid. Thus, the bubble point can be very accurately determined in temperature and pressure in the apparatus 10 according to the invention. On the contrary, a monophasic gas phase can be placed into the inner cylindrical volume 50 at a given pressure. Then, the plunger is actuated to increase the pressure by moving it through the actuator 26 towards the inlet 74 to increase the pressure inside the inner cylindrical volume 50. At regular measurement times, images 113 of the inner cylindrical volume are taken to detect the appearance of liquid droplets, hence allowing a determination of the dew point.

[0130] In a variant, shown in figure 5, the fluid 12 is received in a continuous steady state, as opposed to the semi-batch or unsteady state operation shown in figure 4.

[0131] In this example, the fluid 12 under pressure is continuously received at the inlet 74. The pressure within the inner cylindrical volume 50 is adjusted via the plunger 24, the actuator 26 moving the plunger 24 to maintain the pressure measured by the pressure sensor 28 at a predetermined value.

[0132] The fluid 12 phases separates into the inner cylindrical volume 50. The lighter phase 18 (e.g. oil) is continuously sampled at the upper outlet 78 while the heavier phase 16 (e.g. water) is continuously sampled at the lower outlet 80.

[0133] The lighter phase 18 and the heavier phase 16 are then transported back to the apparatus 140 for example to be reinjected into a core flooding experiment.

[0134] In a variant, the lighter phase is a gas phase 14, and the heavier phase is an oil phase 18 or a water phase 16.

[0135] The apparatus 10 according to the invention is particularly adapted to carry out such measurements in a safe and reliable manner, since the pressure-resisting cylinder 22 solves the safety issues. The imaging by the X-ray source 30 coupled to the detector 32 allows a very precise determination of the pressure at which a phase transition occurs.

[0136] This is particularly the case when fluids are very opaque or when they include emulsions.

[0137] In another variant shown in figure 6, the pressure-resisting cylinder 22 comprises an inner vertical pipe 150 connected to a measuring fluid inlet 152.

[0138] The apparatus 10 is used to inject a measuring fluid 154 into another fluid 12 previously injected and maintained at a predetermined pressure within the inner cylindrical volume 50.

[0139] The measuring fluid 154 forms a sessile drop 156 within the fluid 12, which allows the determination of the surface tension between the fluid and the measuring fluid via the sessile drop method (also referred to as “pendant drop” method).

[0140] In another variant, shown in figure 7, the apparatus 10 comprises a detachable body 160, in particular a detachable ball, and a retainer 162 to retain the detachable body 160 at an upper end of the inner cylindrical volume 50. The retainer 162 is configured to release the detachable body 160 to let it fall in the inner cylindrical volume 50.

[0141] The apparatus 10 according to the invention is then used at follows to estimate the viscosity of a fluid 12 under pressure and at a given temperature. A fluid 12 is injected in the inner cylindrical volume 50 and maintained in pressure by the plunger 24. The detachable body 160 is then released by the retainer 162 and falls into the fluid 12. Images are taken at successive measurement times to image the fall of the detachable body 160 in the liquid 12 under the effect of gravity.

[0142] From the successive positions of the detachable body 160 measured at successive measurement times, the viscosity of the liquid 12 under pressure is calculated by the analyzer 36.

[0143] The apparatus 10 according to the invention allows a very reproducible and automated operation of fluid measurement processes under given temperature and pressure conditions, in a very safe environment, while minimizing the manual interventions by operators and reducing experiment time.

Claims

CLAIMS1 . An apparatus (10) to measure at least a pressurized fluid property, the fluid (12) comprising gas and / or liquid, the apparatus (10) comprising :- at least a pressure-resisting cylinder (22), defining a hollow inner volume (50) configured to receive exclusively gas and / or liquid;- a fluid distributor (23), configured to transport fluid to be measured under pressure in the inner volume (50) of the pressure-resisting cylinder (22); characterized by:- a X-ray source (30), configured to illuminate the inner volume (50) with a beam (92) of X photons, the beam (92) extending along an illumination axis (B-B’);- a detector (32), placed opposite the X-ray source (30) along the illumination axis (B- B’), the inner volume (50) of the pressure-resisting cylinder (22) being interposed between the X-ray source (30) and the detector (32), the beam (92) being configured to illuminate at least a volume of the inner volume (50) without relative movement between the X-ray source (30) and the inner volume (50), the detector (32) comprising a plurality of sensing areas (1 10) configured to detect X photons arising from different points in the inner volume (50);- a radiation protection enclosure (20), defining a inner confinement space (40) containing the or each pressure-resisting cylinder (22), the fluid distributor (23), the X-ray source (30) and the detector (32).

2. The apparatus (10) according to claim 1 , wherein the pressure-resisting cylinder (22) is opaque to visible light.

3. The apparatus (10) according to any one of claims 1 or 2, wherein the pressure-resisting cylinder (22) is made of a material transparent to X-rays.

4. The apparatus (10) according to any one of the preceding claims, wherein the pressure-resisting cylinder (22) comprises a cylinder body (52) defining the inner volume (50) and an inner liner (54) tightly positioned within the cylinder body (52), the cylinder body (52) being in particular made of a composite material comprising reinforcing fibers, the inner liner (54) being preferably composed of a reinforcing polymer, in particular poly ether ether ketone or a metallic liner.

5. The apparatus (10) according to any one of the preceding claims, comprising a plunger (24), movable within the inner volume (50) of the pressure-resisting cylinder (22) and an actuator (26) to move the plunger (24) in the inner volume (50).

6. The apparatus (10) according to claim 5, comprising a pressure sensor (28) configured to sense a fluid pressure within the inner volume (50), the actuator (26) beingconfigured to move the plunger (24) based on a fluid pressure sensed by the pressure sensor (28).

7. The apparatus (10) according to any one of the preceding claims, wherein the X-ray source (30) comprises a controller (94), configured to control the energy of the X photons of the beam (92) to a maximum energy, the maximum energy being lower than 90kV, in particular being comprised 60 kV and 120 kV.

8. The apparatus (10) according to any one of the preceding claims, wherein the pressurized fluid (12) comprises a liquid phase (16, 18) and a gas phase (14), preferentially at least an oil phase (18), a water phase (16) and a gas phase (14), the apparatus (10) comprising an analyzer (36) configured to determine a phase composition of the fluid (12) at a plurality of positions in the inner volume (50) based on signals simultaneously detected by sensing areas (1 10) of the detector (32).

9. The apparatus (10) according to any one of the preceding claims, wherein the distributor (23) comprises at least an inlet (74) to inject fluid (12) into the inner volume (50), in particular comprising an inlet / outlet (74) configured to inject fluid (12) in the inner volume (50) and to recover fluid (12) from the inner volume (50).

10. The apparatus (10) according to claim 9, wherein the distributor (23) comprises at least an outlet (78, 80), preferentially at least two outlets (78, 80) separate from the inlet (74) to recover fluid (12) from the inner volume (50), in particular to recover different phases of fluid (12) in the inner volume (50).11 . The apparatus (10) according to any one of the preceding claims, comprising a measuring fluid injection pipe (150) to create a measuring fluid droplet in a fluid (12) received in the inner volume (50) and / or a detachable body (160), in particular a detachable ball, configured to be dropped in the fluid (12) received in the inner volume (50).

12. The apparatus (10) according to any one of the preceding claims, comprising at least two pressure-resisting cylinders (22), each defining an inner volume (50) configured to receive exclusively gas and / or liquid.

13. A method to measure a pressurized fluid (12) property, comprising:- providing an apparatus (10) according to any one of the preceding claims;- transporting fluid to be measured under pressure in the inner volume (50) of the pressure-resisting cylinder (22) via the fluid distributor (23), the inner volume (50) only containing gas and / or liquid;- illuminating the inner volume (50) with a beam (92) of X photons produced by the X- ray source (30), the beam (92) extending along a first illumination axis (B-B’), at least a volume of the inner volume (50) being illuminated without relative movement between the X-ray source (30) and the inner volume (50);- detecting X photons arising from different points in the inner volume (50) at the plurality of sensing areas (1 10) of the first detector (32), placed opposite the first X-ray source (30) along the first illumination axis (B-B’).

14. The method according to claim 13, comprising calculating a local property of the fluid (12) at a plurality of positions in the inner volume (50) in particular, determining a phase composition of the fluid (12) at a plurality of positions in the inner volume (50) with an analyzer (36) of the apparatus (10).

15. The method according to any one of claims 13 to 14, wherein the apparatus (10) comprises a movable plunger (24), movable in the cylinder (22) to vary the pressure within the cylinder (22), and an actuator (26) to move the plunger (24), the method comprising moving the plunger (24) to modify the pressure of the fluid (12) in the inner volume (50), in particular to determine a bubble point or / and a dew point of the fluid (12).

16. The method according to any one of claims 13 to 15 comprising creating a measuring fluid droplet in the fluid (12) received in the inner volume (50) via a measuring fluid injection pipe (150) to determine an interfacial tension between the measuring fluid and the pressurized fluid (12) and / or dropping a detachable body (160), in particular a detachable ball, into the fluid (12) received in the inner volume (50) to determine a viscosity of the pressurized fluid.

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