WO2025165239A1

WO2025165239A1 - Radial smart motor

Info

Publication number: WO2025165239A1
Application number: PCT/NO2025/050016
Authority: WO
Inventors: Ivar KJØSNES; Bjarne Bugten
Original assignee: Equinor Energy AS
Current assignee: Equinor Energy AS
Priority date: 2024-02-02
Filing date: 2025-01-31
Publication date: 2025-08-07
Anticipated expiration: 2026-08-02
Also published as: GB202401402D0; GB2632892A; GB2632892B

Abstract

: An inflow control device, comprising: an inlet for fluid ingress; an outlet for fluid egress; a rotor operable to rotate about a rotor axis; a fluid passageway arranged along the rotor axis and having a perforated portion for fluidly coupling the inlet to the outlet; and a valve body arranged around the fluid passageway and comprising a threaded coupling, wherein rotation of the rotor is arranged to cause: the valve body to travel along said threaded coupling to thereby advance towards or away from a configuration in which the perforated portion of the fluid passageway is at least partially obstructed by the valve body.

Description

Radial Smart Motor

Technical field

The present invention relates to an inflow control device, and in particular an inflow control device which incorporates a rotor. The present invention also relates to a method of operating the inflow control device, a well system including one or more such inflow control devices, and uses of the inflow control device in a well system.

Numerous types of inflow control device are used to control the flow of fluids (e.g., production fluids) in wellbore systems. Broadly, there are three categories: passive inflow control devices, active inflow control devices, and reactive inflow control devices.

Passive inflow control devices (PICD) are used to restrict inflow to differing degrees along a producing interval in a well. The degree of restriction is sometimes known as the PICD “strength”. There are various types of PICD, including nozzle, orifice, helical and labyrinth. The basic working principle is to vary the strength of each PICD along the base string in such a way as to produce a more uniform inflow. The strength of the PICD is set by the geometry and dimension of the fluid channel and is fixed.

Reactive inflow control devices are able to self-adjust to restrict unwanted fluid flows, depending on the viscosity and density of the reservoir fluid. An example is an autonomous inflow control device (AICD) or autonomous inflow control valve (AICV). A disadvantage with AICDs is that they cannot be fully closed.

Active inflow control devices are controlled electrically to switch between open and closed configurations. These are referred to as electric inflow control devices (elCDs). An improved elCD is desirable.

Summary of the Invention

Aspects of the present invention provide for an inflow control device, a method of operating the inflow control device, a wellbore system, and use of the inflow control device in a wellbore system, as set out by the appended set of claims. According to a first aspect, there is provided an inflow control device. The inflow_control device comprises: an inlet for fluid ingress; an outlet for fluid egress; a rotor operable to rotate about a rotor axis; a fluid passageway arranged along the rotor axis and having a perforated portion for fluidly coupling the inlet to the outlet; and a valve body arranged around the fluid passageway and comprising a threaded coupling, wherein rotation of the rotor is arranged to cause: the valve body to travel along said threaded coupling to thereby advance towards or away from a configuration in which the perforated portion of the fluid passageway is at least partially obstructed by the valve body.

Optionally, the inflow control device includes a motor arrangement, wherein the motor arrangement comprises said rotor, one or more induction coils, and one or more permanent magnets fixed to the rotor.

The outlet may be defined in a lateral wall of an enclosure of the device, and in a closed configuration of the inflow control device, the valve body is arranged within the device at a position that completely obstructs the perforated portion of the fluid passageway and the outlet. This advantageous defines a double-sealing arrangement, which is robust against passing fluid between the inlet and outlet.

The valve body may define one or more ports passing through the valve body. This promotes pressure balancing of the valve body and facilitates low power switching of the inflow control device.

The rotor may also define one or more ports passing through the rotor. This promotes pressure balancing of the rotor, allowing the rotor to rotate without causing significant pressure drops (which may, for example, cause cavitation).

In some examples, the rotor defines an inner and outer portion and the valve body constitutes the inner portion of the rotor.

In some examples, the fluid passageway is fixedly coupled to an enclosure of the device so as to prevent relative rotation therebetween. In some examples, the fluid passageway is rotationally coupled to an enclosure of the device so as to permit relative rotation therebetween.

In some examples, the inflow control device comprises one or more guide rails configured to prevent rotation of the valve body with respect to the enclosure of the device, wherein the valve body comprises a corresponding guide rails channel.

The inflow control device may include a gear system arranged to rotationally couple the inner and outer portion of the rotor according to a preset gear ratio. This allows the torque applied to the valve body, or the speed of switching of the valve body, to be preset according to the preset gear ratio.

In some examples, the fluid passageway is partitioned into a proximal and a distal portion by a gear system which is arranged to rotationally couple the proximal and distal portions according to a preset gear ratio. This allows the torque applied to the valve body, or the speed of switching of the valve body, to be preset according to the preset gear ratio.

In some examples, the preset gear ratio is greater than 1 , thereby causing the valve body to advance between any two configurations comparatively slower (but applying comparatively greater torque). Such a gear ratio is useful in preventing clogging or sticking (e.g., caused by the presence of deposits or scales) of the valve body as it moves through the device.

In other examples, the preset gear ratio is less than 1 , thereby causing the valve body to advance between any two configurations comparatively faster. Such a gear ratio is useful if rapid switching is desirable.

In a specific example, the gear system is a epicyclic gear system, comprising a sun gear, carrier gear, and a plurality of planetary gears.

The threaded coupling may be to the fluid passageway or to a sleeve arranged around said fluid passageway.

According to a second aspect of the present invention, there is provided a method of operating the inflow control device of the first aspect. The method comprises powering a motor to cause the rotor of the inflow control device to rotate relative to an enclosure of the inflow control device; and by consequence, causing the valve body to advance towards or away from the perforated portion of the fluid passageway to thereby change the configuration of the inflow control device.

The powering of the motor may cause the rotor and fluid passageway to rotate relative to the enclosure, or cause the rotor and the valve body to rotate relative to the enclosure.

According to a third aspect of the present invention, there is provided a wellbore system. The wellbore system comprises: a base string arranged to transport production fluids; one or more inflow control device according to the first aspect, wherein the or each inflow control device is arranged within a tubular wall of the base string and operable to switch between an open, closed, and choke configuration to thereby adjust a fluid coupling across the tubular wall; and a controller configured to control the configuration of one or more inflow control devices. As the inflow control device according to the first aspect can, advantageously, be made small (each of its dimensions is from a few millimetres to a few centimetres), the wellbore system can be advantageously made for any practical hole size, also for hole sizes smaller than 8 1 inches in diameter, for example, the standard 6-inch diameter hole size.

According to a fourth and a fifth aspect of the present invention, there is provided use of the inflow control device according to the first aspect as an injector and/or as a production fluid intake device in a wellbore system.

Brief of the

Some embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Figure 1A and 1 B are transverse cross sections of an inflow control device, according to an embodiment.

Figure 2 is a method flow diagram, describing operation of the inflow control device of Figure 1A and 1 B.

Figure 3 is a transverse cross section of an inflow control device, according to another embodiment. Figure 4A and 4B are transverse cross sections of an inflow control device, according to another embodiment.

Figure 5 is a plan-view of the inflow control device of Figure 4A and 4B.

Figure 6 is a method flow diagram, describing operation of the inflow control device of Figure 4A and 4B.

Figure 7 is a traverse cross section of an inflow control device, according to another embodiment.

Figure 8 is a section of a producing interval in a completed well.

Figure 9 is a producing interval of a completed well.

Detailed Description

This disclosure proposes an inflow control device, having a rotor operable to cause, through its rotation, the valve body of the inflow control device to advance towards or away from a relative positon in which the valve body completely obstructs (i.e. a closed configuration of the inflow control device) or permits fluid flow (i.e. an open configuration of the inflow control device) between the inlet and outlet of the inflow control device.

The proposed inflow control device can be operated by powering a motor to cause the rotor of the inflow control device to rotate relative to an enclosure of the device. The rotor rotation causes the valve body to advance towards or away from a perforated portion (depending on the handedness of the threaded coupling and the rotor rotation direction) of the fluid passageway to thereby change the configuration of the inflow control device. In some embodiments, the valve body rotates relative to the enclosure, whereas the fluid passageway remains stationary. In alternative embodiments, the fluid passageway rotates relative to the enclosure, whereas the valve body remains stationary.

Embodiments of the inflow control device and its operation include one or more of the following technical advantages:

• a closed configuration for fluidly decoupling (i.e. preventing fluid flow) the device inlet from the device outlet;

• a pressure balanced valve body, which facilitates low power switching;

• a valve body, whose relative positioning in the device is stable in the absence of power. This means that, in the event of power loss, the previous configuration of the valve (i.e., whether it is closed, open, or partially open) remains unchanged after power loss.

• a rotor arrangement that facilitates greater opening and closing forces. This is useful if obstructions, such as scales or other deposits, are likely to clog the device during prolonged use; and

• multiple choke configurations of differing choke strength.

Also proposed is a wellbore system, including a base string arranged to transport production fluids, one or more of the proposed inflow control devices arranged within a tubular wall of the base string and operable to switch between a closed, open, and choke configuration to thereby adjust a fluid coupling across the tubular wall (i.e., prevent, allow, or restrict fluid flow from entering or exiting the tubular of the base string). The system also includes a controller for controlling the configuration of the one or more inflow control devices.

Particular uses of the proposed inflow control device are as an injector for injecting fluid (e.g., a gas and/or water) into a hydrocarbon reservoir, or, as an inflow intake device for controlling the inflow of production fluids into the tubular of the base string in a well system.

In this context of this disclosure, an inflow control device is in an “open” configuration, if fluid can pass between the inlet and the outlet. An inflow control device is in a “closed” configuration, if no fluid or negligible fluid can pass between the inlet 104 and the outlet 106. There are two types of open configuration: “fully open” (referred to herein simply as “open” configuration”) and “partially open” (referred to herein as a choke configuration). In the open configuration, the valve body is positioned in which it does not obstruct fluid flow between the inlet and outlet at all. In the choke configuration, the valve body is positioned to partially obstruct fluid flow between the inlet and the outlet. In the closed configuration, the valve body is positioned to completely obstruct fluid flow between the inlet and outlet. The inflow control device can be arranged into a plurality of different choke configurations with different choking strengths by positioning the valve body to obstruct the fluid flow to differing degrees. The choking strength increases monotonically as the valve body is positioned to obstruct fluid flow between the inlet and outlet to a greater extent. The embodiments described herein refer to an inlet and an outlet. It will be understood that the terms inlet and outlet are, however, interchangeable because they depend on the direction of fluid flow through the device during use, rather than features inherent to the inflow control device.

That said, this disclosure focusses in particular on the use of the inflow control device in the field of petroleum engineering, e.g., for supplying fluid from a hydrocarbon reservoir into a base string of a well. For these use cases, a proximal end of the inflow control device refers to an end of the inflow control device which is closer to the reservoir. The proximal end is typically where the inlet is located. Likewise, a distal end of the inflow control device refers to an end of the inflow control device, which is further from the reservoir (i.e. closer to the centre of base string tubular). The distal end is typically where the outlet is located.

Figure 1A and 1 B are transverse cross sections of an inflow control device 100 in an open and a closed configuration, respectively.

The inflow control device 100 includes an enclosure 102, an inlet 104 for fluid entry, an outlet 106 for fluid exit, and a fluid passageway 108 in the form of a tubular for fluidly coupling the inlet to the outlet via a perforated portion 110. The perforated portion may include one or more apertures. In some examples, a nozzle 126 is arranged in the inlet. The nozzle functions to control a pressure drop in the fluid passing through the inflow control device. The nozzle shape and size may be selected based on the reservoir type and pressure. Different nozzle shapes and sizes can be used to produce different choking strengths, as is known to the skilled reader. In a well system, the use of the nozzles is typically to homogenise the inflow of fluid into the wellbore across different screens or regions of the wellbore. The dependence of the inflow control devices of the present disclosure to include such nozzles is reduced because each inflow control device can define a plurality of choke configurations of differing choke strength, absent such a nozzle. That said, having the nozzle is beneficial in the event that the inflow control device loses power or if it is becomes otherwise inoperable.

It will be understood that the inlet and outlet may each include one or more openings through the enclosure walls. In the cross section shown in Figures 1A and 1 B, the outlet 106 comprises two openings, although it will be understood that the number of openings can be less or more than this, that are provided in a lateral wall of the enclosure 102 and the inlet is a single opening provided in the proximal wall of the enclosure. In alternative examples (not shown), the outlet 106 is provided in the distal wall of the enclosure. In some examples, the outlet may be annular in form.

A rotor 112 is arranged around and fixedly coupled to the fluid passageway 108. The rotor is configured to rotate, along with the fluid passageway to which it is fixedly coupled, about a notional rotor axis that is coincident with the orientation of the fluid passageway. Bearings 114a, 114b may be provided at the proximal and distal ends of the inflow control device to rotationally couple the fluid passageway to the device enclosure and to facilitate low-friction rotation. To improve induction, the inflow control device may be made up of a soft magnetic material (e.g., iron). In the specific example shown, the rotor 112 and the proximal end of the device closer to the induction coils comprises a soft magnetic material.

A valve body 116 is arranged around and threadedly coupled to the fluid passageway 108. The valve body defines one or more ports (not shown) to permit pressure communication between the space within the enclosure around the fluid passageway. Guide rails 118a, 118b extend through the valve body to guide its movement along the rotor axis with minimal tilting. The guide rails function to prevent the valve body 116 from rotating with fluid passageway 108, or other rotating part. The guide rails also cooperate with a corresponding guide rails channel to function to prevent the valve body getting stuck in the inflow control device, as it moves during use. Each guide rail 118a, 118b is fixedly coupled to the device enclosure 102, for example at either end.

The inflow control device further comprises a motor 120, which is made up of one or more permanent magnets 122, which are inserted within corresponding recesses defined in the rotor, one or more induction coils 124, and the rotor 112 described above. Other ways of incorporating the magnets 122 into the rotor are, however, possible.

Preferably, although not necessarily, the number of permanent magnets is an even number (one for each polarity), greater than or equal to two. The motor may be brushless and be single phase, dual phase, or three phase. For a multiphase motor, the motor includes an induction coil for each phase, and preferably two induction coils for each phase (one for each pole). For example, a three phase motor includes at least 3 induction coils, preferably 6 or more inductions coils. The design details of these motors as such are known to the skilled person and are therefore not discussed in detail herein.

In the open configuration (Figure 1A), the perforated portion 110 is unobstructed by the valve body 116. In use, fluid will be present in the space defined by the enclosure and the fluid passageway. As such, during use, there will be a gap or layer of fluid between the rotor and the valve body, even in the open configuration. The one or more ports defined in the valve body ensure pressure communication between this layer of fluid and the remaining space defined by the enclosure. This promotes pressure equalisation of fluid surrounding the valve body, which reduces the torque required to advance the valve body towards its closed position. This concept is referred to as pressure balancing. While the clearance of the rotor within the device provides for a degree of pressure communication, the rotor may define one or more ports (not shown) to further enhance this communication so that pressure drops caused by rotation of the rotor, and which could cause flashing, are minimised.

In the closed configuration (Figure 1 B), the valve body 116 obstructs the perforated portion 110 to prevent fluid flow between the inlet 104 and outlet 106. Advantageously, in the specific example shown, the valve body also obstructs the outlet to thereby provide a double sealing arrangement. In the closed position, the valve body does not contact the distal enclosure wall of the inflow control device - that is, in use, there will be a gap or layer of fluid between the valve body and the distal wall of the enclosure, when in the closed position. The gap can be maintained by including a valve seat at the distal end of the enclosure (not shown) or by terminating the threaded connection between the valve body and the fluid passageway suitably far away from the distal end of the enclosure. The one or more ports defined in the valve body ensure pressure communication between this gap and the remaining space within the device. This ensures pressure balancing of the valve body in the closed configuration.

In a choke configuration (not shown), the valve body partly obstructs the perforated portion 110 of the fluid passageway. In the choke configurations, the valve body is also pressure balanced by its one or more ports.

Operation of the inflow control device from Figures 1A and 1 B is described, with reference to Figure 2. In step 202, the motor 120 is powered to cause the rotor and the fluid passageway to rotate relative to the enclosure and the valve body. The operation of a motor is known to the skilled reader. Preferably, although not necessarily, the motor may be a three-phase motor to drive smoother rotation of the rotor.

As has already been noted, the guide rails 118a, 118b prevent the valve body from rotating along with the fluid passageway. As such, as the fluid passageway rotates, the valve body travels along its threaded connection with the fluid passageway. Each revolution of the rotor corresponds to the valve body travelling one lead. A lead is the linear travel distance taken along the threaded connection for one revolution. By consequence, the valve body is caused to advance, in step 204, along the rotor axis towards the perforated portion 110. Step 202 is continued until it is determined that the valve body is obstructing the perforated portion at its closed position.

Similarly, the inflow control device can be operated to transition from the closed to the open configuration by powering the motor, as in step 202, to cause the rotor to rotate in an opposite direction compared with the method of Figure 2. The valve body is then caused to advance away from the perforated portion of the fluid passageway. As with Figure 2, the motor can be powered until it is determined that the valve body no longer obstructs the perforated portion of the fluid passageway.

The skilled reader will understand that the rotor rotation direction (i.e. clockwise or anticlockwise) required to cause the valve body to advance towards or away from its open or closed position depends on the handedness of the threaded connection (i.e. whether left or right-handed) between the valve body and the fluid passageway.

It will also be understood that the inflow control device can be operated to switch or transition between (i) an open or closed configuration to (ii) a choke configuration and vice versa, or from (i) one choke configuration to (ii) another choke configuration and vice versa.

If the initial configuration and the final configuration of the device are assumed to be known (i.e., the position of the valve body within the device is known and its intended position at the final configuration is known), then the number of rotor revolutions needed to transition from the initial configuration to the desired configuration can be determined. The number of revolutions can be determined according to (i) a notional separation between the valve bodies in the initial and final configurations along the rotor axis; and (ii) the pitch of the threaded connection between the valve body and the fluid passageway. The motor can then be operated to cause the rotor to perform the determined number of revolutions.

If the initial configuration of the device is not known (i.e. the position of the valve body is assumed to be unknown) but the final configuration is known, then the motor is powered, until the power draw of the motor increases above a predetermined threshold. This is referred to as a reset operation. The threshold is indicative of the rotor being unable to rotate any further as a result of the valve body reaching either end of its threaded connection with the fluid passageway. The position of the valve body will then be known, and the number of revolutions required to transition to the final configuration can be determined, as described above.

In some examples, the final configuration of the device may not be known. This might happen if a particular flow rate through the inflow control device is desired but the configuration required to achieve this flow rate is not known. In such examples, the motor of the device is powered according to an output from a sensor. In a specific example, the output is a flow rate measurement and the sensor is a flow metre. If the measured flow rate is too large, then the motor is powered to advance the valve body towards the closed position. If the measured flow rate is too small, then the motor is powered to advance the valve body towards the open position.

Figure 3 is a transverse cross section of an inflow control device 300, according to an embodiment. The inflow control device is shown in an open configuration.

The inflow control device 300 is a variant of the inflow control device from Figures 1A and 1 B, in which the guide rails 318a, 318b, which extend through the valve body, are fixedly coupled to the device enclosure 102 at one end only. The opposing end of the guide rails is free. In Figure 3, the guide rails are fixedly coupled to the distal end of the device. The remaining features of the device and its operation are as described in relation to Figure 1A, 1 B, and 2. Figure 4A and 4B are transverse cross sections of an inflow control device 400 in an open and a closed configuration, respectively. The inflow control device of Figure 4A and 4B is particularly advantageous because of its compact design, which facilitates manufacturing of the device on the millimetre to centimetre size scale, and because of its comparatively fewer moving parts.

The inflow control device 400 is similar to the device from Figure 1 A and 1 B, except that the valve body forms part of the rotor and the guide rails are not present. The device shown in Figure 4A and 4B can, therefore, be made more compact. Features that equivalent to the embodiment from Figures 1 A and 1 B are denoted by the same or like reference numeral.

The outlet in Figure 4A and 4B is also shown as being provided in the distal wall of the device enclosure (cf. to the double seal arrangement), although this is not essential. Double seal arrangements for the inflow control device shown in Figure 4A and 4B are also envisaged.

In the open configuration (Figure 4A), the perforated portion 110 of the fluid passageway 108 is unobstructed by the valve body, whereas in the closed configuration (Figure 4B), the perforated portion 110 is completely obstructed by the valve body.

In more detail, the inflow control device 400 includes an enclosure 402, an inlet 104 for fluid entry, an outlet 406 for fluid exit, and a fluid passageway 108. The fluid passageway in Figure 4A and 4B is fixedly coupled with the enclosure, for example, at the distal and proximal wall of the enclosure, to prevent relative rotation therebetween.

The rotor 412 of the inflow control device in Figure 4A and 4B includes an inner portion 412a, which is threadedly coupled to the fluid passageway 108, and an outer portion 412b. The inner portion constitutes the valve body. The rotor is configured to rotate about the fluid passageway, which remains stationary during operation. Rotation of the rotor causes the rotor, and hence the valve body which forms the inner portion of the rotor, to advance towards or away from the closed position, dependent on the direction of rotation and the handedness of the threaded connection. Put differently, as the rotor rotates, the valve body travels along its threaded connection with the fluid passageway. As with the embodiment from Figure 1A and 1 B, the rotor 412 defines one or more ports 428 to permit pressure balancing of the rotor (and the valve body). These ports can be defined in the inner portion (i.e. the valve body) and/or the outer portion of the rotor.

The inflow control device from Figure 4A and 4B is shown in plan-view in Figure 5. The plan-view shows a cross section of the enclosure 402, fluid passageway 110, rotor with inner portion 412a (i.e. valve body) and outer portion 412b, permanent magnets 422, and induction coils 424, which are contained in the lateral walls of the enclosure 402. The permanent magnets 422 are shown as being rectangular in cross section in Figure 5. Other shapes in cross section, such as circles, ellipses, or other quadrilaterals for the permanent magnets, are, however, possible. The enclosure 402, rotor and valve body are shown as circular in cross-section and being concentrically arranged with respect to one another. Other shapes in cross section for the enclosure, rotor and valve body are possible, provided that the rotor and valve body are able to freely rotate within the enclosure.

In the specific example shown, the inflow control device comprises a three phase motor arrangement 500. The three phase motor arrangement includes a rotor 412 with six permanent magnets 422, and nine induction coils 424. The permanent magnets and induction coils are circumferentially arranged around the rotor and the device enclosure 402, respectively. As has already been noted, the motor may, alternatively, be single phase or dual phase and may include any number of induction coils and permanent magnets. The inflow control devices from Figures 1A, 1 B, 3, and 7 may also incorporate the motor arrangement from Figure 5 (although the valve body in those Figures does not form part of the rotor).

To improve induction in these motor arrangements, the inflow control devices may be made up of a soft magnetic material (e.g., iron), as mentioned in relation to Figure 1. For example, the rotor and the proximal end of the enclosure immediately adjacent to the induction coils may be made from a soft magnetic material.

Operation of the inflow control device from Figures 4A and 4B is now described, with reference to Figure 6. In step 602, the motor is powered to cause the rotor and the valve body (which forms the inner portion of the rotor) to rotate relative to the enclosure and the fluid passageway. The operation of a motor is known to the skilled reader.

As the fluid passageway and the device enclosure are fixed relative to one another, rotation of the rotor causes the valve body is travel along its threaded connection with the fluid passageway (which remains stationary). Each revolution of the rotor corresponds to the valve body travelling one lead. By consequence, the valve body is caused to advance, in step 604, along the rotor axis towards the perforated portion 110. Step 602 is continued until it is determined that the valve body is obstructing the perforated portion at its closed position.

It will be understood that the device can be operated to transition between a closed and open, choke and closed, and between different choke configuration, substantially as described in relation to Figure 2 (but with the valve body rotating rather than the fluid passageway).

Figure 7 is a transverse cross section of an inflow control device 700, according to an embodiment. The inflow control device is a variant of the inflow control device from Figure 1 , in which the fluid passageway is split into a proximal 708a and a distal portion 708b, and further comprising a gear system 730 which rotationally couples the proximal portion to the distal portion. Features that equivalent to the embodiment from Figures 4A and 1 B are denoted by the same or like reference numeral.

In more detail, the inflow control device 700 includes an enclosure 702, an inlet 104 for fluid entry, an outlet 106 for fluid exit, and a fluid passageway 108, as described above in relation to Figure 1A and 1 B. As with Figure 1A and 1 B, the fluid passageway is rotationally coupled to the enclosure.

As previously noted, the guide rails 718a, 718b, which extend through the valve body 116, guide its movement along the rotor axis and prevent the valve body 116 from rotating because they are fixedly coupled to the device enclosure 702. In the specific example shown, the enclosure includes a dividing wall or partition 732 that separates the proximal portion of the device, which includes the motor, and the distal portion of the device which includes the valve body and the perforated portion 110. The guide rails are shown fixedly coupled to the dividing wall 732 and the distal wall of the enclosure.

The dividing wall 732 may fluidly isolate the proximal portion of the device from the inlet and outlets. This means that the rotor can be arranged to rotate through vacuum (or other low-resistance medium). Alternatively, the dividing wall may include one or more ports (not shown) to fluidly couple the proximal portion to the inlet and outlets.

The gear system 730 advantageously means that the mechanical advantage of the device (i.e. the ratio of the torque output by the valve body and the torque input by the rotor) can be controlled. A mechanical advantage greater than 1 (i.e. a positive mechanical advantage) can be achieved if the gear ratio of the system is less than 1 , i.e., if the valve body rotates at a lower angular velocity than the rotor. A negative mechanical advantage should be interpreted accordingly.

In a specific example, the gear system is an epicyclic gear system, comprising a central sun gear, a carrier gear arranged around the sun gear, and three or more planetary gears which rotationally couple the sun gear to the carrier gear. For a positive mechanical advantage, the sun gear is coupled to the proximal portion of the fluid passageway and the carrier gear is coupled to the distal portion of the fluid passageway. For a negative mechanical advantage, the sun and carrier gear are coupled instead to the distal, and proximal portion of the fluid passageway, respectively.

Operating the device with a positive mechanical advantage means that the torque exerted by the valve body as it moves within the enclosure is higher, but the valve body moves more slowly. This is beneficial if scales or blockages are likely to form inside the device enclosure, since the higher torque can dislodge the blockages more effectively.

Operating the device with a negative mechanical advantage means that the torque exerted by the valve body as it moves within the enclosure is lower but the valve body moves more quickly. This is useful if the speed at which the device open and closes is important. Turning back to Figure 4, the rotor 412 optionally includes a gear system to rotationally couple the inner (i.e. the valve body) and outer portion of the rotor. The gear system may be the epicyclic gear system, substantially as described in relation to Figure 7.

Figure 8 is a schematic illustration of a section 800 of a producing interval in a completed well. The completed well extends through a hydrocarbon reservoir 802. The section comprises a base string 804 arranged to transport production fluids to the surface, a screen 806 configured to block particulates (such as sand) and one or more inflow control devices 808 configured to control the inflow of fluid from the reservoir. The inflow control device 808 in Figure 8 is shown as being arranged completely within the tubing wall of the base string but this is not essential. In some examples, space constraints may require that the inflow control device extend into the bore defined by the base string and/or extend radially out from it. The extension into the base string is preferably minimal so that wireline access is not obstructed, and the extension out from the base string is preferably less than the difference between the outer radius defined by the screen and the base string. This is to ensure that the base string can be run smoothly into the well bore and get caught up in obstructions in the well. Notably, unlike traditional producing intervals of well systems, an inner string is not needed. In some examples, each screen has a different nozzle size in order to control the inflow of fluid through each of the screens (for example to homogenise flow across different screens, which may be arranged in parts of a reservoir that produces production fluids at varying rates). This is beneficial because, while the inflow control devices of this disclosure can define multiple choke configurations, they cannot do so if they fail or are otherwise left inoperable. The nozzles on the screens can therefore improve the robustness of the system to failure of the inflow control devices. The screen is optional and may be replaced with a single opening to facilitate flow into the inflow control device 808. The inflow control device can be any described in relation to Figures 1A, 1 B, 3, 4A, 4B, and 7. In some examples, the inflow control devices is configured to inject a fluid (such as a gas or water) from the base string into the reservoir in which the completed well is arranged. The inflow control device can, therefore, function as an injector in an injector well. Gas or water injection operations are known to the skilled reader, per se.

When the pressure of the reservoir 802 exceeds the pressure within the base string, fluid is urged to flow from the reservoir through the screen and into the one or more inflow control devices 808 via one or more channels defined within the base string wall. The arrows in Figure 8 denote the direction of fluid flow. Each inflow control device 808 comprises an inlet for fluid entry and an outlet for fluid exit. The completed section of a well may be in a horizontal configuration, a deviated configuration or a vertical configuration (relative to the direction of the Earth’s gravitational pull). In a deviated configuration, the inclination of the well to the vertical is between 0 and 90 degrees.

It is envisaged that the inflow control devices of the present disclosure may be used in a well system having any hole size, be that a conventional hole size (typically 6 inch or 8.5 inch in diameter), larger hole sizes or smaller hole sizes. The well system may be a single well bore or a multilateral well with a plurality of well bores. The hole size of a single wellbore system refers to drilled hole size below the last casing shoe, i.e. , where the well is directly exposed to the geological formations. For multilateral wells, the hole size in the branches of the well system may be different than the mother wellbore. Appropriate operation of the inflow control devices allows production to be optimized for different reservoirs (which may have different properties) in one well. Such well systems may include a very large number of inflow control devices (e.g., several hundred per well).

Figure 9 is a schematic illustration of a producing interval 900 of a completed well located within a reservoir. The interval 900 contains four zones. Each zone is separated by a zonal isolation element 902, such as a swell packer. Swell packers, in particular, are configured to expand in the presence of reservoir fluid to prevent fluid, and to an extent pressure, communication between neighbouring zones 904. In some examples, the swell packers are configured to swell in the presence of other fluids. Brine, in particular, may be present following the installation of the completion string and so a packer that swells in the presence of brine conveniently facilitates swelling of the packers prior to production. For an injector well, the swell packers may be configured to swell in water or brine. Each zone includes one or more screens 806, and each screen may be associated with one or more inflow control devices.

In some examples, each zone comprises one or more sections of base string connected together. The joints, connecting each section, are not shown. Electrical connections for transferring power across the joints and for delivering power to the inflow control devices are known to the skilled reader, for example as described in WO/2022/186696 with reference to Figure 11A-D, 12, 13, and 14. The entire contents of WO/2022/186696 is incorporated herein by reference. As an example, power and data signals may be transferred via a powered tubing which runs down the well, and across each joints between the base strings via conductive (or inductive) coupling connectors. Similar connectors can be used to transfer power and signal across any joints in the screen 806, if present and if screens are replaced with tubing joints. Alternatively, the power can be transferred by clamping a power cabling onto these joints. Preferably, although not necessarily, the power and data signals are transferred wirelessly between the power tubing and the inflow control device and likewise between the power cabling and the inflow control device. The absence of the wired connections to the inflow control devices reduces installation times significantly. Such a system is also much more robust to local failure or shorting at one of the inflow control devices. This is because, with a direct conductive connection, failure or shorting of one of the inflow control devices could result in loss of power and signal capability to all the inflow control devices installed below the failed one.

In the specific example shown in Figure 9, the zone 804 comprises one section of base string, and each zone comprises one screen 806, which allows fluid to flow from the reservoir into the base string 804 via one inflow control device. In general, each zone 904 includes one or more screens 806 and each or the screen includes a one or more inflow control devices. In a specific example, there are 10 sand screens 806 per zone and each screen includes 3 inflow control devices. A signal cable 908 is arranged in an annulus surrounding the base string. The signal cable provides power to the inflow control devices 808 and their circuitry 910 during use. The inflow control devices can typically be arranged at one or both ends of the screen section, for example, beneath a collar which protects them against mechanical stresses and which isolates them from allowing other fluids into the base string. Preferably, although not necessarily, the outer diameter of the collar is less than or equal to the outer diameter defined by the screen so that the tubing can be run into the hole more easily. Alternatively, the inflow control devices can be arranged inside the screens themselves.

The configuration of each inflow control device in a given zone (i.e., open, choke, or closed) can be controlled using a controller (not shown). The controller can selectively control each device, by causing a signal generator to emit an electrical signal unique to that device. Each inflow control device may include circuitry comprising a microprocessor, or share circuitry amongst a plurality of its neighbouring inflow control devices. The microprocessor is configured to decode the signal (e.g., determine the signal contains instructions intended for it) and cause powering of the induction coils of the motor to effect rotation of the rotor, based on the decoded signal. Frequency-shift keying is one known way to achieve this, and is explained in more detail in WO/2023/033657. The entire contents of WO/2023/033657 are incorporated herein by reference.

In the event of power loss or when the induction coils are not being operated to move the rotor, all the induction coils in the inflow control devices are switched off. As the valve body is threadedly coupled to the fluid passageway, it is, advantageously, mechanically stable. This means that in the event of a power loss, each inflow control device will maintain its configuration. This is beneficial because production continue to take place, even under loss of power.

The inflow control devices described above may define an outer dimension on the millimetre to centimetre scale. In a specific example, the inflow control device has a height (the dimension between the proximal and distal ends of the enclosure) of 5 to 20mm, 5 to 10mm, or 15 to 20mm, and a width and length of (the dimension between the lateral walls of the enclosure) 10 to 20 or 15 to 25 mm.

Variants of the embodiments described above are envisaged. For example, the inlet may, alternatively or additionally, be provided in a lateral wall of the enclosure. The outlet may be provided in a distal wall and/or a lateral wall of the enclosure. The inlet and outlets in the illustrated embodiments are shown to extend in a thickness direction of the respective enclosure wall, but it will be understood that they may also extend in a direction transverse to the thickness direction (e.g., along the length of the wall). Any one of the inlet or outlet openings may, therefore, extend from the lateral wall to the proximal/distal wall.

While the valve body is shown as being threadedly coupled to the fluid passageway in the illustrated embodiments, it will be understood that the valve body may be threadedly coupled to a sleeve which is arranged around the fluid passageway instead. The sleeve may also define a perforated portion to define a fluid pathway between the inlet and outlet. In variants of the embodiments shown in Figures 1A, 1 B, and 3, the sleeve (not shown) may rotate with, or instead of the fluid passageway 108. The fluid passageway 108 may, therefore, be fixedly coupled to the device enclosure 102, rather than being rotationally coupled to it via bearings 114. In variants of the embodiments shown in Figures 4A, 4B, and 7, the valve body may be separated from the fluid passageway by the sleeve (not shown) to which it is threadedly coupled.

Although the invention has been described in terms of preferred embodiments as set forth above, it should be understood that these embodiments are illustrative only and that the claims are not limited to those embodiments. Those skilled in the art will be able to make modifications and alternatives in view of the disclosure which are contemplated as falling within the scope of the appended claims. Each feature disclosed or illustrated in the present specification may be incorporated in the invention, whether alone or in any appropriate combination with any other feature disclosed or illustrated herein.

Claims

CLAIMS:

1. An inflow control device, comprising: an inlet for fluid ingress; an outlet for fluid egress; a rotor operable to rotate about a rotor axis; a fluid passageway arranged along the rotor axis and having a perforated portion for fluidly coupling the inlet to the outlet; and a valve body arranged around the fluid passageway and comprising a threaded coupling, wherein rotation of the rotor is arranged to cause: the valve body to travel along said threaded coupling to thereby advance towards or away from a configuration in which the perforated portion of the fluid passageway is at least partially obstructed by the valve body.

2. An inflow control device according to claim 1 , comprising a motor arrangement, wherein the motor arrangement comprises said rotor, one or more induction coils, and one or more permanent magnets fixed to the rotor.

3. An inflow control device according to any one of claims 1 to 2, in which the outlet is defined in a lateral wall of an enclosure of the device, and in a closed configuration of the inflow control device, the valve body is arranged within the device at a position that completely obstructs the perforated portion of the fluid passageway and the outlet.

4. An inflow control device according to any one of the preceding claims, in which the valve body defines one or more ports passing through the valve body.

5. An inflow control device according to any one of the preceding claims, in which the rotor defines one or more ports passing through the rotor.

6. An inflow control device according to any one of the preceding claims, in which the rotor defines an inner and outer portion and the valve body constitutes the inner portion of the rotor.

7. An inflow control device according to any one of the preceding claims, in which the fluid passageway is fixedly coupled to an enclosure of the device so as to prevent relative rotation therebetween.

8. An inflow control device according to any one of claims 1 to 5, in which the fluid passageway is rotationally coupled to an enclosure of the device so as to permit relative rotation therebetween.

9. An inflow control device according to any one of claims 1 to 5, and 8, further comprising one or more guide rails configured to prevent rotation of the valve body with respect to the enclosure of the device, wherein the valve body comprises a corresponding guide rails channel.

10. An inflow control device according to any one of claims 1 to 7, in which the inflow control device includes a gear system arranged to rotationally couple the inner and outer portion of the rotor according to a preset gear ratio.

11 . An inflow control device according to any one of claims 1 to 5, 8 and 9, in which the fluid passageway is partitioned into a proximal and a distal portion by a gear system which is arranged to rotationally couple the proximal and distal portions according to a preset gear ratio.

12. An inflow control device according to claims 10 or 11 , in which the preset gear ratio is greater than 1 , thereby causing the valve body to advance between any two configurations comparatively slower.

13. An inflow control device according to claims 10 or 11 , in which the preset gear ratio is less than 1 , thereby causing the valve body to advance between any two configurations comparatively faster.

14. An inflow control device according to any one of claims 10 to 13, in which the gear system is a epicyclic gear system, comprising a sun gear, carrier gear, and a plurality of planetary gears.

15. An inflow control device according to any one of claims 1 to 14, in which the threaded coupling is to the fluid passageway or to a sleeve arranged around said fluid passageway.

16. A method of operating the inflow control device according to any one of claims 1 to 15, the method comprising: powering a motor to cause the rotor of the inflow control device to rotate relative to an enclosure of the inflow control device; and by consequence, causing the valve body to advance towards or away from the perforated portion of the fluid passageway to thereby change the configuration of the inflow control device.

17 A method according to claim 16, in which powering the motor causes the rotor and fluid passageway to rotate relative to the enclosure.

18. A method according to claim 16, in which powering the motor causes the rotor and the valve body to rotate relative to the enclosure.

19. A wellbore system, comprising: a base string arranged to transport production fluids; one or more inflow control device according to any of claims 1 to 15, wherein the or each inflow control device is arranged at least partially within a tubular wall of the base string and operable to switch between an open, closed, and choke configuration to thereby adjust a fluid coupling across the tubular wall; and a controller configured to control the configuration of one or more inflow control devices.

20. Use of the inflow control device according to any one of claims 1 to 15 as an injector in a wellbore system.

21. Use of the inflow control device according to any one of claims 1 to 15 as a production fluid intake device in a wellbore system.