FR3014475A1 - INJECTION OF A FLUID IN A HYDROCARBON RESERVOIR - Google Patents

Abstract

The invention relates to a device (50) for regulating the flow rate of a fluid in a hydrocarbon reservoir well, comprising a fluid inlet (62), a fluid outlet (64), a stator (52), a rotor (54) rotatably mounted relative to the stator along an axis from the fluid inlet to the fluid outlet, the stator and the rotor forming progressing cavities from the fluid inlet to the fluid outlet when the rotor is rotated relative to the stator, and a control system (56) of the rotational speed of the rotor relative to the stator. The device allows regulation of the flow rate of a fluid in an improved hydrocarbon reservoir well.

Description

A present invention relates to a device for regulating the flow rate of a fluid in a well. of a hydrocarbon reservoir, as well as a hydrocarbon production facility comprising the device, a method of injecting a fluid into a hydrocarbon reservoir using the device, and a process for producing hydrocarbons comprising the process injection. The use of polymer solutions, especially polyacrylamide, is known in the context of the enhanced recovery of hydrocarbons contained in an underground formation (so-called "EOR" technique, for "Enhanced Oil Recovery"). Thus, after hydrocarbon recovery operations by means of the natural pressure of the deposit, called "primary", or even by injection of water or gas ("secondary recovery") to maintain the pressure of the underground formation, it proceeds generally to a hydrocarbon recovery that can be qualified as "secondary" or "tertiary" depending on the prior steps actually implemented, during which a polymer solution is injected into the subterranean formation by one or more injection wells and extracting a mixture of hydrocarbons and polymer solution by one or more production wells. It is preferred to use a polymer solution, not water, because of the often too great mobility of the water relative to that of the oil in place in the subterranean formation: the efficiency of the scanning is improved by adding polymer to the injection water, as well as the production conditions, for example due to a percentage of produced water reduces as the viscosity of the oil in place is greater than that of the water. This gives a higher rate of recovery of the oil in place over the production period, especially when it is commonly decided to stop production, for example because of a percentage of water produced too high. making the operation uneconomic. The flow rate of such a fluid injection can advantageously be regulated by a regulating device provided for this purpose.

For example, when multiple injection wells are used, it is usually necessary to operate at different pressures at different wells, in order to adapt to the local configuration of the subterranean formation, and to correct the effects of heterogeneity. of said subterranean formation. Now, several injection wells (or all the injection wells) are generally supplied with fluid by the same source of polymer solution. It is therefore necessary to regulate the flow rate for each injection well, particularly in the context of offshore operations. R: \ 34300 \ 34310 SNP (linked to 34673) \ 34310-130924-texte.docx 3014475 2 Various devices are known, in the form of fixed systems, for example interchangeable orifice plates so as to adapt the fluid passage section. if necessary, or in the form of control valves, provided for such regulation.

For example, Cameron Willis proposes a control valve model that consists of a cage pierced with holes. The fluid inlet is on the periphery of the cage, and the outlet is in the center of the cage. The accessible surface for the fluid inlet is adjusted by a movable piston moving parallel to the axis of the cage. For a given flow rate, the pressure drop (i.e. pressure) experienced by the fluid through this control valve increases as the accessible surface at the fluid inlet decreases. However, this system, like most other systems operating by fluid shear, leads on the one hand to an important and irreversible dissipation of mechanical energy (hydraulic pressure) in heat, and on the other hand to a strong degradation of the solutions. of polymers used for the enhanced recovery of hydrocarbons, and therefore a decrease in the viscosity thereof, which greatly affects their effectiveness. In addition, US 4,510,993 discloses a flow control valve for polymer solutions, in which the flow rate is regulated by a needle penetrating into an orifice. The document states that the polymers are not degraded as long as the flow rate does not exceed 30 gallons / min, ie 7 m3 / h. However, it is known that such a geometry (needle valve type) also operates by shear and therefore also degrades the hydraulic energy and the viscosity of the fluid it "laminates". Thus, the degradation of the polymer solutions in this type of system becomes high at more realistic flow rates of the order of 100 m 3 / h. In addition, such a system presents significant risks of mechanical wear. US 3,477,467 discloses a flow control valve suitable for a polymer solution, wherein the pressure drop is achieved by passing the polymer solution through a vertical tube filled with sand or beads. The adjustment of the quantity of sand or balls makes it possible to regulate the flow rate. However, this system also has the drawback of irreversibly degrading the fluid hydraulic energy as well as the viscosity of the polymer solutions, and it also presents significant risks of mechanical wear of the valve and damage to the porous medium with the weather. Moreover, its implementation is difficult. US 4,617,991 proposes a flow control system comprising a device actuated by the transport of a polymer solution, such as a hydraulic pump or a motor. The system avoids the degradation of a low flow rate polymer solution (at most about 1.3 m3 / h). However, it does not permit R: \ 34300 \ 34310 SNP (related to 34673) \ 34310-130924-text.docx 3014475 3 to avoid the phenomenon of degradation at a higher rate. Indeed, although the energy is dissipated outside rather than inside the pipe, the degradation remains a function of the geometry of the dissipation system inside the pipe. The geometry of the control system is also not optimized for a line 5 for injecting a fluid into a hydrocarbon reservoir. Finally, this system is not optimal from the point of view of the energy balance of the oil installation. US 4,276,904 discloses an apparatus for modifying a fluid flow rate by passing the fluid through a limited number of tubes of different lengths and diameters. The pressure drop, again obtained by shearing the fluid, this time due to the regular friction of the fluid on the inner wall of the tubes, is adjusted by passing the fluid in one of the combinations between the different tubes. This system is bulky, difficult to implement (the apparatus comprises in particular a large number of valves, which must be operated independently, at the output of each of the tubes) and not very flexible (that is to say that it makes it difficult to fine-tune the pressure drop and the flow). Such a system can not allow to create a sufficient pressure drop at a high rate. In addition, this solution also leads to irreversible degradation of hydraulic energy in heat and the viscosity of the fluid. The object of the present invention is to provide a device for regulating the flow rate of a fluid in a hydrocarbon reservoir well at least partially overcoming the aforementioned drawbacks. More particularly, the invention aims to provide a device for regulating the flow rate of a fluid in a hydrocarbon reservoir well which is easy to implement, has a low risk of mechanical wear, and does not degrade 25%. possible polymers contained in the fluid, even at the high flow rates that are usual for injection into a hydrocarbon reservoir in the context of the EOR. To this end, the present invention provides a device for regulating the flow of a fluid in a hydrocarbon reservoir well, comprising a fluid inlet, a fluid outlet, a stator, a rotor rotatably mounted relative to the stator. Along an axis from the fluid inlet to the fluid outlet, the stator and the rotor forming progressing cavities from the fluid inlet to the fluid outlet when the rotor is rotated relative to the stator, and a system for regulating the speed of rotation of the rotor relative to the stator. According to preferred embodiments, the device comprises one or more of the following characteristics: the stator is of deformable material, preferably elastomer; the stator is mounted tightly around the rotor; R: \ 34300 \ 34310 SNP (linked to 34673) \ 34310-130924-texte.docx 3014475 4 - the rotor is metallic, preferably chromed steel; the rotor is mounted in a housing inside the stator, the rotor and the housing being of helical shape; the sections of the rotor and the housing in the stator have, respectively, two and three vertices, or, three and four vertices; the rotor is further adapted to be rotated relative to the stator by the fluid when the pressure at the fluid inlet is greater than the pressure at the fluid outlet; the system for regulating the speed of rotation of the rotor relative to the stator 10 comprises a braking system of the rotor; - The device further comprises a power converter from braking electrical energy, and a connector adapted to the supply by the converter of an electrical network of hydrocarbon production facility; The system for regulating the speed of rotation of the rotor relative to the stator comprises a motor adapted to drive the rotor in rotation with respect to the stator; the device forms an eccentric rotor pump; and / or the control system comprises a pressure sensor at the fluid outlet and / or a system for counting the fluid flow rate at the fluid outlet. The invention also proposes a hydrocarbon production facility comprising a fluid injection line in a hydrocarbon reservoir, and at least one regulating device, as described above, mounted in the injection line of fluid, the fluid inlet of the device being mounted upstream and the fluid outlet 25 of the device being mounted downstream. According to preferred embodiments, the installation comprises one or more of the following characteristics: the fluid injection line comprises at least one fluid injection well opening into the hydrocarbon reservoir and a pipe arriving at the well, The regulating device being mounted in the pipe, inside a false well or inside the injection well; the fluid injection line comprises a plurality of fluid injection wells opening into the hydrocarbon reservoir, an injection fluid line supplying a manifold with fluid, and a plurality of pipes each connecting the manifold to an injection well. respective, and for each injection well, a control device, as described above, mounted downstream of the manifold; and / or R: \ 34300 \ 34310 SNP (related to 34673) - the installation further comprises a pump adapted to feed the injection fluid line with the fluid. The invention also proposes a method for injecting a fluid into a hydrocarbon reservoir, comprising supplying fluid to several fluid injection wells opening into the hydrocarbon reservoir, and for each well of injection, the regulation of the injection rate of the fluid in the hydrocarbon reservoir with a control device as described above, independently of the other wells.

In preferred embodiments, the method comprises one or more of the following features: the fluid comprises a viscous solution, preferably containing polymers; and / or the fluid comprises a fracturing gel, preferably thixotropic.

The invention also proposes a process for the production of hydrocarbons, comprising the injection of a fluid into a hydrocarbon reservoir according to the injection method described above, and the recovery of hydrocarbons by at least one well of hydrocarbons. production leading into the tank. Other features and advantages of the invention will appear on reading the following description of a preferred embodiment of the invention, given by way of example and with reference to the appended drawing. Figure 1 shows an example of a process for producing hydrocarbons. Figure 2 shows an example of a hydrocarbon production facility. Figures 3 and 4 show examples of fluid flow control devices in a hydrocarbon reservoir well. A device for regulating the flow of a fluid in a hydrocarbon reservoir well is proposed. The device comprises a fluid inlet, a fluid outlet, a stator, a rotor and a system for regulating the speed of rotation of the rotor relative to the stator. The rotor is rotatably mounted relative to the stator along an axis 30 from the fluid inlet to the fluid outlet. The stator and the rotor form progressing cavities from the fluid inlet to the fluid outlet when the rotor is rotated relative to the stator. This device makes it possible to regulate the flow rate of a fluid in a hydrocarbon reservoir well which is easy to implement, particularly adapted in terms of geometry to a line for injecting a fluid opening into a hydrocarbon reservoir and comprising an injection well, or a production line of a fluid leaving a production well and comprising a production well. The R: \ 34300 \ 34310 SNP (linked to the 34673) \ 34310-130924-text.docx 3014475 6 device has low risks of mechanical wear, and does not degrade any polymers contained in the fluid, even at high flow rates which are customary for injection into a hydrocarbon reservoir. The device may in particular be provided for regulating a flow rate of fluid injection into a reservoir. In other words, the device is adapted to be mounted in a fluid injection line in a reservoir and to control the flow of the fluid downstream (ie tank side), so that the fluid can be injected into the reservoir at a desired rate. For this, the device comprises a fluid inlet, a fluid outlet, and an assembly comprising a stator and rotor which form progressive cavities adapted to fluid transport, as well as adequate sizing. The stator + rotor assembly thus constitutes a fluid transfer system from the fluid inlet to the fluid outlet, thus along the axis of rotation of the rotor. Thus, the device can be mounted in an injection line fed with fluid and opening into the reservoir, the fluid inlet of the device being mounted upstream (ie fluid supply side) and the fluid outlet of the device being mounted. downstream (ie tank side). The rotor is rotatably mounted with respect to the stator along an axis of rotation which goes (substantially) from the fluid inlet to (substantially) the fluid outlet. In other words, the axis of rotation of the rotor is substantially longitudinal, in the direction of fluid flow in the injection line. Thus, the device can extend in length in the injection line, and thus have a geometry particularly suitable for the injection line. In addition, the transfer of the fluid being in the direction of flow, the device is particularly suitable for minimizing the degradation of any polymer chains contained in the fluid.

The fluid transfer system ensures the flow of fluid from the inlet to the outlet, thus ensuring the delivery of the fluid to its destination. Since the fluid transfer system transfers the fluid through progressing cavities, the fluid transfer system is adapted to carry out the fluid transfer by volumetric displacement of the fluid. This means that the transfer system transfers the fluid from the fluid inlet to the fluid outlet by moving constant volumes of the fluid (the volumes being defined by the progressing cavities), which is explained in more detail below. The regulation of the flow rate of the fluid thus transferred is ensured by the control system, which is in this case adapted to regulate the speed of rotation of the rotor relative to the stator, and consequently the volumetric displacement speed of the fluid produced by the transfer system. In other words, the rotation of the rotor relative to the stator displaces predetermined volumes of the fluid, and the control system regulates the SNP (related to 34673). speed of this displacement. For example, the control system is adapted to regulate, e.g. mechanically, electrically, hydraulically and / or magnetically, the speed of rotation of the rotor relative to the stator. This transfer system is simple to implement. This makes it possible to regulate the fluid flow rate at the outlet of the device. The control system can perform any type of regulation that is suitable for injecting fluid into a hydrocarbon reservoir, for example with a view to an enhanced recovery of the hydrocarbons contained in the fluid. The reservoir. These hydrocarbons may contain oils having a high coefficient of viscosity, from a few centipoise (cPo) (for example greater than 3 cPo, for example 5 cPo) to several hundred (for example greater than 100 cPo), or even thousands of centipoise ( for example, greater than 1000 cPo), which makes the EOR suitable for their production. Thus, the device and its control system can be adapted to rotational speeds of the rotor which ensure flow rates adapted to the intended application, which can range from almost zero to a very high value which, in the example of injection in a reservoir for EOR purposes, may depend inter alia properties of the reservoir rock and the target hydrocarbon, and for example flow rates greater than 10 m 3 / h, for example of the order of 100 m3 / h per injection well. The control system can provide a constant injection rate, which may be calibrated in advance, or variable (i.e. dynamically modifiable, e.g., by remote control or automatically). In any case, the injection rate can be capped by considerations on the hardware components of the device. In addition, the injection flow may have a lower bound related to the pressure with which the fluid feeds the input of the device. Various examples of components of the control system are described in detail below.

The control system can provide a variable injection rate by varying the speed of rotation of the rotor. In this case, different versions of the same device can be used for different situations where the desired injection rate is different. This also makes it possible to optimize the injection flow rate according to the conditions of the reservoir, for example hydrocarbon production conditions. For example, the control system can regulate the speed depending on the physical and / or geological characteristics of the reservoir, or the needs of good management of the production of this hydrocarbon reservoir. In particular, in the case of the EOR, the control system can regulate the speed according to criteria provided to the device to ensure an optimal efficiency of the oil sweep in place in the tank. These criteria, for example the injection pressure which will vary with the flow rate injected into the injection well in communication with the reservoir, can be determined beforehand by the SNP studies (34673). 34310-130924-texte.docx 3014475 8 carried out jointly by a geoscience team (including geophysicist, geologist, reservoir engineer, geomechanic) and a team specialized in the operation and performance of wells. As has already been mentioned, thanks to the progressing cavities, the fluid transfer system 5 is adapted to carry out the transfer of the fluid by volumetric displacement of the fluid. In other words, the transfer system admits the incoming fluid by successive volume elements which it itself defines the dimension by its own design, for example with physical walls, elements which it then moves, to constant volume (even if the shape of the volume elements can be changed) to the output. As may be appreciated by those skilled in the art, during this movement, the volume may not be perfectly constant, but rather substantially constant, in that there may be leakage rates resulting in small volume variations. for example due to mechanical deformations of the device under the action of the pressure forces involved during this movement. The concept of volumetric displacement is known in the field of positive displacement pumps. A positive displacement pump is indeed a pump performing a volumetric displacement of fluid, by a mechanical action performed by a mechanism providing positive mechanical energy to the pump. As will be seen below, the device may form or include a positive displacement pump, but it may also include only the portion of the positive displacement pump that does not include the mechanism providing positive mechanical energy. Thus, the device can in both cases correspond to a positive displacement pump, in that in both cases it can include the transfer system of the volumetric pump, that is to say the part of the positive displacement pump. ensuring volumetric displacement (without understanding the mechanism providing positive mechanical energy). The transfer system can thus be that of a displacement pump with progressing cavities, and in particular a helical pump with progressing cavities with eccentric rotor (commonly known as pump "Moineau" by the name of its inventor), the most suitable the geometry of injection or production lines of hydrocarbon production facilities. Unlike the solutions of the prior art which regulate the flow of injection of the fluid by waste (ie by restriction of the section of the conduit in which the fluid flows), the device regulates the injection flow rate by a volumetric displacement 35 whose speed is regulated. Thus, the fluid experiences fewer shear stresses and experiences reduced entropy creation compared to solutions operating at a restriction end of the duct section. The fluid is therefore less degraded. This is particularly advantageous in the case where the fluid is a polymer solution. The device can indeed regulate the injection rate without degrading the polymer chains, and at the relatively high rates envisaged for the EOR. Furthermore, since it is sufficient to regulate the speed of rotation of the rotor to regulate the injection flow, the system is simple to implement and relatively small, especially since it can extend in length in the injection line. Moreover, in the case of the use of a pump with progressing cavities, and in particular of the "Sparrow" type, the mode of displacement of the fluid makes it possible to obtain a regular injection flow rate, or even a constant flow rate, so without For example, in the conventional case of using piston pumps with reciprocating translational movement, there are hydraulic interruptions as there are, for example. This advantage is particularly significant for extending the life of the equipment, the quality of the fluids and the efficiency of the processes used. The stator may be of deformable material, preferably elastomer for a simple embodiment. Thanks to this material, the stator can be mounted tightly around the rotor (ie the stator exerts a pressure on the rotor in the idle state), unlike traditional non-deformable stator pumps that require a rigid clearance to ensure lubrication of the system. Indeed, due to its deformability, the stator deforms during operation, which ensures lubrication by temporarily creating a clearance with between the stator and the rotor. This allows the device to adapt to a potentially fluctuating viscosity of the fluid. In addition, the fluid experiences even less shear, and the device performs a more efficient fluid transfer. In this example, the injection rate thus obtained is independent of the viscosity of the fluid. Also, the device has a better life, undergoing less wear due to friction with the fluid and being more tolerant to the presence of high proportions of solid particles. Such a device, because of its exceptional ability to transfer highly viscous fluid (up to several thousand centipoise) and fluids loaded with high proportions of solids (up to several tens of% vol), allows consider additional applications, for example the injection of viscous gels, eg fracturing, eg with a viscosity greater than 1000 centipoise (eg around 5000 centipoise), for example thixotropic gels, as used for hydraulic fracturing of rocks at the bottom of the wells. In addition, these gels can be loaded with solid particles, known as "proppants", intended to keep open fractures created in the rock by the injected fluid. The rotor can be metallic, for example chromed steel, for a long life and good strength. The rotor may further be adapted to be rotated relative to the stator by the fluid when the pressure at the fluid inlet is greater than the fluid outlet pressure. This means that the energy required to move the fluid from the inlet to the outlet can come from a greater pressure at the fluid inlet than at the fluid outlet. Indeed, even if, when the device is mounted in an injection line as mentioned above, the fluid outlet is on the reservoir side and therefore subjected to the pressure prevailing in the reservoir, the injection line can, as can be seen in FIG. will see later in more detail, be powered by a pump delivering a pressure greater than the pressure of the tank. Thus, the device judiciously uses this pressure differential to move the fluid. In this case, the rotational speed control system of the rotor may comprise a rotor braking system. The pressure differential can, in the absence of any braking, drive the rotor in rotation with respect to the stator at a certain speed, implying a corresponding velocity of volumetric displacement. The braking system makes it possible to reduce this speed, and thus to regulate the injection flow rate. Advantageously, the braking system can exert a variable braking (i.e exert different braking forces, dynamically modifiable), which allows to dynamically regulate the injection rate. The braking can be slaved to the input pressure and / or the fluid outlet pressure of the device, which can be known or measured by a sensor provided for this purpose. The braking can also or alternatively be slaved to the speed of movement of the rotor, in order to deliver the desired injection rate. This is possible for example if the device 25 comprises a system for counting this speed. More generally, the device may comprise a system for counting the fluid flow rate at the fluid outlet, i.e. the injection flow rate in the fluid injection application. The mechanical energy extracted by the fluid in flow, resulting from the braking, can therefore be dissipated outside the device, which has the advantage of avoiding the heating of fluid which would degrade the fluid and its viscosity (especially in presence of polymer solution). However, the device may comprise a mechanical energy recovery system resulting from the braking of the rotor, e.g. converting it for example into electrical energy (i.e. a power converter from braking into electrical energy). This is possible because of the reversible nature of the flow control performed by the device, the principle of which is based on a volumetric and therefore substantially isentropic displacement. This makes it possible to optimize the operation from an energy point of view, since the energy thus recovered can be used at a later date, for example in the following manner: to power the control system. For example, the braking system may comprise a machine, for example, synchronous electric, adapted to produce energy, that is to say operating as a "generator". The energy converter may for example comprise a dynamoelectric machine, e.g. participating in braking. In addition, the device may comprise a connector adapted to the supply by the converter of an electrical network of hydrocarbon production facility. In other words, the device is adapted, via the connector which conventionally comprises electrical connectors, to supply the electrical energy recovered as a result of braking to an electrical network serving the hydrocarbon production plant is the well whose fluid flow rate is regulated by the device. This allows optimization of the sizing of the installation, particularly in terms of energy sources. The system for regulating the displacement velocity of the fluid 15 may furthermore or alternatively comprise a motor, e.g. synchronous, adapted, reversibly if necessary, to drive the rotor in rotation relative to the stationary part. In this case, the device forms a volumetric motor pump. This allows to feed the injection line with less pressure, when a pump as mentioned above is used for this purpose. The same engine can also be adapted to perform the braking mentioned above. Thus, the motor can be synchronous and controlled by a voltage variator, e.g. alloyed with braking, which can be either rheostatic, magnetic or eddy current. In all cases, the braking energy can be recovered to an electrical network, and / or to participate in the power supply of the device. If appropriate, a reserve can be provided for storing the energy thus produced with braking. The storage tank may take the form of a battery if the energy is recovered in electrical form, a lifting of a weight or compression of a spring, if the energy is recovered in mechanical form, or of a tank of compressed gas if the energy is recovered in hydraulic form. The resist can be used as a "buffer" to facilitate regulation of the assembly, for example as a complementary power supplier available for startup. The device can be included in a hydrocarbon production facility comprising a fluid injection line in a hydrocarbon reservoir as mentioned above. The regulating device is then mounted in the fluid injection line, the fluid inlet of the device being mounted upstream and the fluid outlet of the device being mounted downstream. Such an installation allows a recovery of the hydrocarbons contained in the reservoir assisted by a fluid injection, possibly containing a polymer solution, with precisely controlled injection flow, without degrading the possible polymers of the solution. Thus, a less concentrated solution can be used, which allows optimized and less expensive production of hydrocarbons.

Figure 1 shows an example of such a hydrocarbon production process using the device. The method of the example comprises a method of injecting (S10, S20) a fluid into a hydrocarbon reservoir using the device. The fluid may be a viscous solution, particularly a polymer solution. The addition of polymer 10 makes it possible, in fact, to increase the viscosity of the solution relative to that of water, from a few centipoise to several tens of centipoise, to approximate the viscosity of the oil in place in a reservoir. of hydrocarbons, in order to create a flow resistance to improve the viscosified water injection sweep in said hydrocarbon reservoirs.

The use of the device not only makes it possible to regulate the injection flow in a precise manner, but also to not degrade the polymers possibly present in the fluid. The production process also includes the recovery S30 of hydrocarbons by at least one production well opening into the reservoir. Recovery S30 is improved by injection (S10, S20), as is known from the EOR technique by injection of chemicals (such as polymers, biopolymers, with or without surfactants, etc. ). The process is carried out continuously, so that the injection (S10, S20) is substantially simultaneous with the recovery S30, with FIG. 1 being illustrative as to the order of the steps.

In the example, the injection comprises the feed S10 fluid of several fluid injection wells opening into the hydrocarbon reservoir. The injection also comprises, for each injection well, the regulation S20 of the injection rate of the fluid in the hydrocarbon reservoir with the device, independently of the other wells. The method therefore uses a different version of the same device per well. Thus, the S20 control of the injection flow rate can be done for each well independently of the other wells (i.e. the injection rates can be different). The regulation is therefore adapted to the conditions of each of the wells, and the overall recovery S30 is therefore improved, with less degradation of the polymers, lower consumption, and an overall improved economy.

FIG. 2 shows a hydrocarbon production plant 20 comprising the device adapted to carry out the method of FIG. 1. SNP (34673-linked) 34310-130924-text.docx 3014475 13 installation 20 comprises a fluid injection line consisting of several pipes in which the injection fluid flows. The injection line comprises in particular several fluid injection wells 38 opening into the reservoir 26 of hydrocarbons. Three injection wells 38 are shown in the figure, but any number suitable for optimum coverage of the reservoir 26 is conceivable to take into account the geological complexity of the reservoir, the quality of the fluids present in the reservoir, the geographical location reservoir (onshore, offshore, in deep sea), and inherent constraints. The injection line comprises an injection fluid line 34 supplying fluid to a manifold 40.

The injection fluid line 34 is a main line receiving the fluid and distributing it to all the injection wells 38 drilled in the tank 26 via a manifold (here manifold 40), acting as a distributor. The injection fluid line 34 is located on a seabed 24, and is fed by a "riser" 32 (ie a substantially vertical pipe) from a main station, eg a floating production unit. , storage and unloading 28 (known under the acronym FPSO, for "Floating Production Storage and Offloading") located at the marine surface 22. The injection fluid line 34 is more particularly supplied with fluid by a main pump 42 located on the FPSO 28. The installation 20 is indeed for an offshore application, but the principle remains the same for a terrestrial application, in which case, in the absence of FPSO and riser, the Injection fluid line would be directly fed from the main pump. The injection line also comprises several ducts 36 each connecting the manifold 40 to a respective injection well 38. Each well 38 is connected to a respective wellhead 44 installed on the seabed 24. And for each injection well, a respective regulating device 50 is mounted downstream of the manifold 40, the upstream fluid inlet and the fluid outlet downstream. Thus, the installation 20 retains an optimal infrastructure, with a single injection fluid line 34, a manifold 40 distributing the injection fluid to several wells 38 drilled to the tank 26, while allowing a control of the flow rate fluid injection case by case, according to the 38 well considered, and without degradation of polymers possibly contained in the injection fluid and without excessive consumption of hydraulic energy (minimal entropy created), thanks to the attribution to each Well 50 of the device 50. The devices 50 can indeed regulate the injection rate locally, independently of each other.

The regulating devices 50 may in particular be mounted in the conduits 36. This allows a simple implementation. In particular, the devices 50 can be mounted inside a false well, not shown in the figure. This R: \ 34300 \ 34310 SNP (linked to the 34673) \ 34310-130924-text.docx 3014475 14 reduces the surface footprint of the installation 20. In fact, in the context of the EOR, for flows referred, the control device described may be relatively bulky, and have for example a length greater than 1 meter, eg of the order of ten meters. Passing the ducts 36 in a false well 5 and mounting the devices 50 in the ducts 36, inside the false wells therefore allows a better use of the space whether in offshore where having space requires expensive infrastructure or "onshore" where environmental constraints may lead to preferring to put equipment in wells dug in the ground.

Reference is now made to FIGS. 3 and 4 which illustrate an example of the device for regulating the flow rate of a fluid in a hydrocarbon reservoir described above, and which can therefore be used in fluid injection processes and described in the process of FIG. 1, and which can be included in a hydrocarbon production installation, in particular the installation 20 of FIG. 2. Such a configuration of the device allows a relatively very precise regulation. injection rate, with relatively little degradation of the fluid and very little degradation of mechanical energy. FIG. 3 shows the control device 50 of the example, comprising the stator 52 and the rotor 54, rotatably mounted relative to the stator 52. In the example, the rotor 54 is mounted inside the stator 52 in a housing that can be seen through the open view of the stator 52 shown in the figure. As can be seen in the figure, the rotor 54 and the housing are helically shaped. On the other hand, the rotor speed control system 54 includes the motor 56, which can be synchronous and be adapted to drive the rotor 54 in rotation relative to the stator 52. Thus, the device 50 forms a positive displacement gear pump. helical rotor with eccentric rotor, in particular a pump type "sparrow" in the illustrated example. The helical shapes of the rotor 54 and the housing (stator) are such that progressing cavities 58, shown filled with a volume of fluid in the figure, are formed and move the fluid from the fluid inlet 62 to the fluid outlet. 64, 30 which define the axis of rotation of the rotor 54. The fluid flow is represented by arrows 66 in the figure. Such a pump makes it possible to carry out a fluid flow particularly suitable for a polymer solution. Indeed, the device 50 causes little degradation of the polymer chains, and is both accurate and resistant to injection rates (and therefore rotational speeds of the rotor), for example several hundreds of revolutions per minute. Furthermore, in the example, the rotor 54 is adapted to be driven in displacement with respect to the stator by the fluid itself when the pressure P1 in R: \ 34300 \ 34310 SNP (linked to 34673) \ 34310-130924- The fluid inlet 62 is greater than the pressure P2 at the fluid outlet 64. The pressure P1 is generally known. The pressure P2 may be measured by a pressure sensor 68 at the fluid outlet 64. In this case, the motor 56 may also constitute a braking system, the motor then being adapted to brake the rotor 54 or to rotate it. depending on P1, P2 and the desired injection rate, so as to achieve this desired injection rate. For example, FIG. 4 shows an example of an operating diagram of the motor 56. The synchronous motor 56 is coupled to a voltage regulator 70 which regulates the power supply as a function of the desired flow rate and the measured pressure P2. by the sensor 68. This makes it possible to control the speed of rotation of the rotor 54. The flow control with a device such as the eccentric rotor pump 50 is much simpler and more accurate than with dynamic systems (centrifugal, venturi or calibrated orifice with or without needle or other hydraulic passage restriction system, for example capillary tubes). The device 50 is suitable for polymer solutions because it does not degrade the polymer chains. It is also robust and allows working with the presence of sand or other solid particles more or less abrasive as the proppant. It is therefore very unlikely to generate accumulations of organic or inorganic deposits as could be other systems. Finally the device 50 can be adapted in underwater version 20 for use in offshore. In addition, its maintenance, including the replacement of the rotor, is easy. Regarding the dimensions of the rotor 54 and the stator 52, the sections of the rotor 54 and the housing in the stator may have, respectively, two and three vertices. In this case, the device 50 is particularly suitable in the case where Pl is greater than P2 and the motor 56 acts as a braking system. Alternatively, the sections of the rotor 54 and the housing in the stator may have, respectively, three and four vertices (motor). In this case, the device 50 is particularly suitable in the case where Pl is less than P2 and the motor 56 drives the rotor 54 in rotation.

The rotor 54 may be metallic, preferably chromed steel. In addition, the stator 52 may be of deformable material, for example an elastomer. Thus, the stator 52 can undergo deformations allowing the creation of a leakage flow, as mentioned above, allowing a lubrication of the device 50. The precise shapes, dimensions and materials can be provided to optimize and control the system. leakage flow in order to have the effect of lubrication with a minimum of fluid shear and a good distribution of the work of the braking forces or overpressure of the fluid in all the cavities, all along the rotor and the stator. They can also be adapted to the conditions of temperature and pressure of the injected fluid, for example a spur-type pump with a metal stator can also be adapted to the temperature and pressure conditions of the injected fluid. be considered to withstand higher temperatures, for example above 120 ° C. Of course, the present invention is not limited to the examples and the embodiment described and shown, but it is capable of many variants accessible to those skilled in the art. R: \ 34300 \ 34310 SNP (linked to 34673) \ 34310-130924-text.docx

Claims (20)

REVENDICATIONS1. A device (50) for regulating the flow rate of a fluid in a hydrocarbon reservoir well, comprising: a fluid inlet (62), a fluid outlet (64), a stator (52), a rotor (54) rotatably mounted relative to the stator along an axis from the fluid inlet to the fluid outlet, the stator and the rotor forming progressing cavities from the fluid inlet to the fluid outlet when the rotor is rotated relative to the stator, and a control system (56) of the rotational speed of the rotor relative to the stator. 2. Device according to claim 1, wherein the stator is deformable material, preferably elastomeric. 3. Device according to claim 2, wherein the stator is mounted tightly around the rotor. 4. Device according to one of claims 1 to 3, wherein the rotor is metallic, preferably chromed steel. 5. Device according to one of claims 1 to 4, wherein the rotor is mounted in a housing within the stator, the rotor and the housing being helically shaped. 6. Device according to claim 5, wherein the sections of the rotor and the housing in the stator have, respectively, two and three vertices, or three and four vertices. 7. Device according to one of claims 1 to 6, wherein the rotor is further adapted to be rotated relative to the stator by the fluid when the pressure at the fluid inlet is greater than the pressure at the fluid outlet. R: \ 34300 \ 34310 SNP (linked to 34673) \ 34310-130924-text.docx 3014475 18 8. Device according to claim 7, wherein the rotor speed control system relative to the stator comprises a braking system (56) of the rotor. 5 9. Device according to claim 8, further comprising a power converter from braking electrical energy, and a connector adapted to the supply by the converter of an electrical network of hydrocarbon production facility. 10 10. Device according to one of claims 1 to 9, wherein the system for regulating the speed of rotation of the rotor relative to the stator comprises a motor adapted to drive the rotor in rotation with respect to the stator. 11. Device according to claim 10, wherein the device forms an eccentric rotor pump. 12. Device according to one of claims 1 to 11, wherein the control system comprises a pressure sensor at the fluid outlet and / or a system for counting the fluid flow rate at the fluid outlet. 20 13. A hydrocarbon production plant (20) comprising: a fluid injection line in a hydrocarbon reservoir, and at least one regulating device (50) according to one of claims 1 to 13 mounted in the line fluid injection, the fluid inlet of the device being mounted upstream and the fluid outlet of the device being mounted downstream. The hydrocarbon production plant according to claim 13, wherein the fluid injection line comprises at least one fluid injection well (38) opening into the hydrocarbon reservoir (26) and a conduit (36). ) arriving at the well, the regulating device (50) being mounted in the pipe, inside a false well or inside the injection well. The plant of claim 13 or 14, wherein the fluid injection line comprises: a plurality of fluid injection wells (38) opening into the hydrocarbon reservoir (26), an injection fluid line. (34) supplying fluid to a manifold (40), a plurality of pipes (36) each connecting the manifold (40) to a water well (34). injection (38) respectively, and for each injection well, a control device (50) according to one of claims 1 to 13 mounted downstream of the manifold. 5 16. Installation according to claim 15, further comprising a pump (42) adapted to feed the injection fluid line (34) with the fluid. 17. A method of injecting a fluid into a hydrocarbon reservoir, comprising: supplying (S10) fluid of several fluid injection wells opening into the hydrocarbon reservoir, and for each well of injection, regulating (S20) the injection rate of the fluid in the hydrocarbon reservoir with a regulating device according to one of claims 1 to 13, independently of other wells. 18. The method of claim 17, wherein the fluid comprises a viscous solution, preferably containing polymers. 20 19. The method of claim 18, wherein the fluid comprises a fracturing gel, preferably thixotropic. A process for producing hydrocarbons comprising: injecting (S10, S20) a fluid into a hydrocarbon reservoir according to the method of claim 17, 18 or 19, and recovering (S30) hydrocarbons by at least one production well opening into the tank.