Radial smart motor

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; and a valve body comprising at least one port through the valve body, wherein rotation of the rotor is arranged to cause the valve body to advance towards or away from a position wherein the device defines a pathway for fluid to pass between the inlet and the outlet via said at least one port through the valve body.

Description

[0001] Radial Smart Motor

[0002] Technical field

[0003] 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.

[0004] Research Disclosure no. 719043 discloses an electric inflow control device with a radial motor. The inflow control device includes a valve body, which rotates relative to a fluid passageway so as to travel up and down a threaded coupling therebetween. In a closed configuration, perforations in the tubular defining the fluid passageway are obstructed by the valve body, whereas, in an open configuration, the valve body is positioned away from the perforations so as to permit free passage of fluid through the device.

[0005] 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.

[0006] 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.

[0007] 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.

[0008] Summary of the Invention

[0009] According to aspects of the present invention, there is provided an inflow control device, a method of operating the inflow control device, a wellbore system, and use of the inflow control device as a producer, an injector or production fluid intake device, as set out by the appended set of claims.

[0010] According to a first aspect of the present invention, there is provided an inflow control device, comprising: an inlet for fluid ingress; an outlet for fluid egress; a rotor operable to rotate about a rotor axis; and a valve body comprising at least one port through the valve body, wherein rotation of the rotor is arranged to cause the valve body to advance towards or away from a position wherein the device defines a pathway for fluid to pass between the inlet and the outlet via said at least one port through the valve body. The port advantageously facilitates increased flow rates through the inflow control device, from the inlet to the outlet.

[0011] Rotation of the rotor may be arranged to cause the valve body to advance from (i) a position within the device in which fluid is obstructed from passing between the inlet and outlet via said at least one port through the valve body, to (ii) a position within the device in which fluid is able to pass between the inlet and outlet via said at least one port through the valve body.

[0012] The inflow control device may comprise two opposing enclosure walls and a lateral wall extending therebetween, and the inlet comprises one or more openings through one of the two opposing enclosure walls and / or the lateral wall, and through which fluid is able to pass into the inflow control device.

[0013] The inflow control device may comprise one or more guides rails extending through a respective one of the one or more ports through the valve body. Optionally, the inflow control device includes one or more further ports, absent any guide rail (i.e., through which guide rails do not extend). In some examples, the rotor comprises one or more openings through the rotor and through which fluid can flow from the inlet to the outlet.

[0014] The outlet may comprise one or more openings through which fluid is able to pass out from the inflow control device, and wherein the one or more openings of the inlet and outlet respectively extend through the two opposing enclosure walls of the inflow control device. This facilitates installation of the inflow control device in the base string. In a closed configuration of the device, the one or more ports of the valve body and these openings of the outlet are misaligned (with respect to the rotor axis) and the valve body is positioned to sealingly engage with the enclosure wall through which said openings of the outlet extend, to thereby prevent fluid passing from out of the device.

[0015] In some examples, any one of the following are circumferentially shaped about the rotor axis: the one or more ports of the valve body; the one or more ports of the rotor; and the one or more openings of the inlet.

[0016] According to a second aspect of the present invention, there is provided an inflow control device, comprising: an inlet for fluid ingress; an outlet for fluid egress; a rotor operable to rotate about a rotor axis; and a valve body, wherein rotation of the rotor is arranged to cause the valve body to advance towards or into a position within the device in which the valve body obstructs free passage of fluid between the inlet and outlet, wherein, the inflow control device comprises two opposing enclosure walls and a lateral wall extending therebetween, and the inlet comprises one or more openings through one of the two opposing enclosure walls and / or the lateral wall and through which fluid is able to pass into the inflow control device, and wherein in an open position the valve body defines a pathway with the lateral wall for fluid to pass between the inlet and outlet. This advantageously facilitates increased flow rates through the inflow control device, from the inlet to the outlet via the pathway.

[0017] The rotor of the inflow control device according to the first or second aspect may be the valve body. The rotor and / or valve body may include one or more ports / opening, as described in relation to the first aspect. The outlet of the inflow control device according to the first or second aspect may comprise one or more openings through an enclosure wall of the inflow control device and through which fluid is able to pass out from the inflow control device. These one or more openings extend through a lateral wall of an enclosure of the device and, in a closed configuration of the device, the valve body is positioned within the device so as to sealingly engage with said one or more openings so as to prevent fluid from passing out of the device.

[0018] The inflow control device according to the first or second aspect may include a motor arrangement, wherein the motor arrangement comprises the aforementioned rotor, one or more induction coils, and one or more permanent magnets fixed to the rotor.

[0019] According to a third aspect, there is provided a method of operating the inflow control device according to the first aspect. The method comprises powering a motor to rotate the rotor of the inflow control device to thereby cause the valve body to advance into or out from a position within the device in which fluid is able to pass between the inlet and the outlet via the at least one port through the valve body.

[0020] According to a fourth aspect, there is provided a method of operating the inflow control device according to the second aspect. The method comprises powering a motor to rotate the rotor of the inflow control device to thereby cause the valve body to advance into or out from a position within the device in which the valve body obstructs free passage of fluid between the inlet and outlet via the pathway defined between the lateral wall and the valve body; and thereby causing fluid flow, from the one or more openings through one of the two opposing enclosure walls and / or the lateral wall to the outlet, to be obstructed or permitted.

[0021] According to a fifth aspect, there is provided a wellbore system, comprising: a base string arranged to transport production fluids; one or more inflow control devices according to the first or second aspect, 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. According to a sixth and seventh aspect, there is provided use of the inflow control device according to the first or second aspect as an injector or a production fluid intake device in a wellbore system, such as the wellbore system according to the fifth aspect.

[0022] Brief of the

[0023] Some embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

[0024] Figure 1A, 1 B, and 1C are transverse cross sections of an inflow control device, according to an embodiment.

[0025] Figure 2 is a method flow diagram, describing operation of the inflow control device of

[0026] Figure 1A, 1 B, and 1C.

[0027] Figure 3 is a plan-view of the inflow control device of Figures 1A to 1C.

[0028] Figure 4A, 4B, and 4C are transverse cross sections of an inflow control device, according to another embodiment.

[0029] Figure 5A, 5B, and 5C are transverse cross sections of an inflow control device, according to another embodiment.

[0030] Figure 6A and 6B are transverse cross sections of an inflow control device, according to another embodiment.

[0031] Figure 7 is a method flow diagram, describing operation of the inflow control device of Figure 6A and 6B.

[0032] Figure 8A and 8B are transverse cross sections of an inflow control device, according to another embodiment.

[0033] Figure 9 is a transverse cross section of an inflow control device.

[0034] Figure 10 is a transverse cross section of an inflow control device, according to an embodiment.

[0035] Figure 11 is a section of a producing interval in a completed well.

[0036] Figure 12 is a producing interval of a completed well.

[0037] Detailed Description

[0038] This disclosure proposes an inflow control device, having an inlet for fluid ingress, an outlet for fluid egress, a rotor operable to rotate about a rotor axis and a valve body, which comprises at least one port therethrough. Rotation of the rotor is arranged to cause the valve body to advance into or out of a position within the device in which fluid is able to pass between the inlet and the outlet via said at least one port (i.e. an “open” valve position). Alternatively or additionally, rotation of the rotor can cause the valve body to advance into or out of a position in which the valve body prevents fluid passing from the inlet to the outlet via the at least one port (i.e. a “closed” valve position).

[0039] The proposed inflow control device can be operated by powering a motor to rotate the rotor. The rotation of the rotor then causes the valve body to advance into or out of a position within the device in which fluid is able to pass between the inlet and the outlet via the at least one port through the valve body. The device therefore has a travelling port. In some embodiments, the valve body rotates and the enclosure of the device remains stationary. In alternative embodiments, the valve body remains stationary and the rotor rotates along with part of the enclosure of the device. In some embodiments, the rotor is the valve body. In other embodiments, the rotor and valve body are separate components.

[0040] Embodiments of the inflow control device and its operation include one or more of the following technical advantages:

[0041] • a high flow rate of fluid through the device in the open configuration. This is achieved through the use of one or more openings in the proximal and distal wall of the device enclosure and the one or more ports through the valve body.

[0042] • a closed configuration for fluidly decoupling (i.e. preventing fluid flow) the device inlet from the device outlet;

[0043] • a valve body, the relative positioning of which in the device is stable in the absence of electrical power. This means that, in the event of power loss, the previous position of the valve (i.e., whether it is in a closed, open, or partially open position) remains unchanged after power loss.

[0044] • 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

[0045] • multiple choke configurations of differing choke strength.

[0046] 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.

[0047] 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.

[0048] 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 in a position 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.

[0049] 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.

[0050] 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. 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. 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. The inflow control devices described herein include a rotor and a references to “axial” denotes a direction that is coincident with the rotation axis of the rotor. Likewise, references to “radial” denote a direction that is orthogonal to the rotation axis of the rotor. In some embodiments described herein, an inner-facing distal face and / or inner-facing proximal face of the device enclosure walls may be referred to as a valve seat (assuming the valve body is able to establish contact with those walls or a landing arrangement on said walls). A peripheral wall refers to an exterior wall of the inflow control device, as opposed to an inner wall, which may or may not be present in some embodiments. .

[0051] Figure 1A, 1 B and 1C are transverse cross sections of an inflow control device 100 in an open, a choke, and a closed configuration, respectively.

[0052] The inflow control device 100 includes an enclosure 102, which defines an inlet 104 for fluid entry, an outlet 106 for fluid exit, and which includes a central tubular 108 (i.e., a hollow axle) with a perforated portion 110. The perforated portion may comprise one or more openings in the central tubular. The central tubular is fixedly coupled with the enclosure, for example, at the distal and proximal wall of the enclosure, to prevent relative rotation therebetween.

[0053] The inlet 104 in Figure 1A to C comprises (i) a plurality of openings defined in a proximal wall of the enclosure and (ii) the perforated portion 110. The outlet comprises one or more openings through distal wall of the enclosure. In some examples, a nozzle 126 is provided in the proximal end of the central tubular. The opening defined by the nozzle may be regarded as forming part of the inlet 104 for fluid entry.

[0054] The device further comprises a motor, which is made up of a rotor 112 comprising an inner portion 112a and an outer portion 112b, one or more induction coils 124, and one or more permanent magnets 122, which are provided in the rotor. In some examples, the induction coils 124 are arranged within or around the lateral wall of the enclosure. The permanent magnets 122 may be located at the outer portion 112b of rotor to promote stronger magnetic responses. Alternatively, or in addition, the permanent magnets may be located at the inner portion 112a of the rotor (not shown). 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.

[0055] Preferably, although not necessarily, the number of permanent magnets 122 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.

[0056] The rotor is coupled to the central tubular 108 by a threaded connection so that it can freely rotate about the tubular 108. As has been noted above, the central tubular is fixedly coupled to the enclosure, meaning that the rotor can also freely rotate about the device enclosure. The tubular defines a notional rotor axis that is coincident with the orientation axis of the tubular. The rotor can be viewed as the valve body for the device, as, in the open and choke configurations (Figures 1A and 1 B), the rotor defines a passage through which fluid can flow from the inlet to the outlet, whereas, in the closed configuration (Figure 1 C), the rotor prevents the flow of fluid from the inlet and the outlet.

[0057] In the open and choke configurations, the rotor permits two types of passage for fluid flow through the device, from the inlet to the outlet. The first passage is through the one of the openings in the proximal wall of the device (i.e. part of inlet 104 in Figure 1 A, 1 B, and 1 C), through the one of the one or more ports 128 defined through the rotor, between the distal face of the rotor and the distal wall of the enclosure, and then through to one of the one or more openings in the distal wall of the device (i.e. part of the outlet 106 in Figure 1A, 1 B, and 1C). The second passage is through the perforated portion 110 of the central tubular, between the distal face of the rotor and the distal wall of the enclosure, and then through to one of the one or more openings in the distal wall of the device.

[0058] In the closed configuration (Figure 1 C), the rotor obstructs both the first and second fluid passage types. The first passage type is obstructed by bringing the rotor into sealing engagement with the outlet 106 and / or bringing the rotor into sealing engagement with the inner-facing distal wall of the enclosure. The second passage type is obstructed by the rotor at it travels along its threaded connection to sealingly engage against the perforated portion 110.

[0059] In some embodiments (not shown), the distal enclosure wall includes a landing arrangement (i.e. a valve seat) in order to space apart the rotor / valve body and the distal enclosure wall in the closed configuration. As a result, fluid can be present on opposing sides of the valve body and the valve body remains substantially pressure balanced. This prevents the formation of a vacuum layer beneath the valve body in the closed position, which could inhibit subsequent opening of the device. In such embodiments, the outlet 106 is arranged to extend radially into the lateral wall of the enclosure and at a position that allows the rotor to sealingly engage the outlet (i.e. spaced from the distal wall by at least the gap between the rotor and the distal enclosure wall). In a specific example, the landing arrangement comprises a plurality of pins upon which the valve body sits in its closed position.

[0060] In the specific example shown in Figure 1A to 1 C, the ports 128 through the rotor are shown as being aligned with the openings in the proximal wall of the enclosure (i.e. the inlet). The skilled reader will understand that, in these embodiments, perfect alignment is not necessary but greater alignment is, in general, preferable for increasing the maximum achievable flow rate of fluid through the device.

[0061] In the specific example shown in Figure 1A to 1 C, the openings in the distal wall of the enclosure are shown to traverse into the lateral wall of the enclosure, before passing through the distal wall of the enclosure. In this regard, the openings may be regarded as having a radially extending and a distally extending portion through the enclosure walls. Alternatively (not shown), the openings include a distally extending portion only, provided that the ports 128 through the rotor are out of alignment with these openings, when the rotor is in the closed position (i.e. sealingly contacts with the distal wall of the enclosure), such that fluid is prevented from passing through the rotor and out from the outlet. In yet another alternative (not shown), the openings include a radially extending portion only and exit from through the lateral wall of the device enclosure.

[0062] Operation of the inflow control device of Figure 1 A to 1C is now described, with reference to the method flow diagram of Figure 2. In step 202, the motor is powered to cause the rotor 112 to rotate relative to the enclosure and the central tubular 108. The operation of a motor is known to the skilled reader.

[0063] As the central tubular and the device enclosure are fixed relative to one another, rotation of the rotor (i.e. the valve body) causes the inner portion 112a of the rotor to travel along its threaded connection with the central tubular (which remains stationary). By consequence, the rotor is caused to advance, in step 204, along the rotor axis towards the perforated portion 110 or towards the distal wall of the enclosure. Step 202 continues until it is determined that the inner radial portion of the rotor obstructs the perforated portion 110 and the rotor establishes sealing contact with the outlet, at its closed position. Instead of a threaded connection to the central tubular, a threaded connection to the inner edge of the lateral wall of the device can be provided to translate the rotational motion into displacement along the axis.

[0064] It will be understood that, while the distal face of the rotor is shown as being substantially planar in transverse cross section, this is not to be regarded as essential. In some examples, the distal face of the rotor may be convex and the inner-facing distal wall of the enclosure may be concave (i.e., complementary in profile) so as to promote an improved sealing connection therebetween, especially where the outlet 106 extends into the distal enclosure wall. Other complementary shaped profiles are also possible.

[0065] 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 rotor (i.e. valve body) is then caused to advance away from the perforated portion of the central tubular and out of sealing contact with the outlet. 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 central tubular and no longer engages against the outlet.

[0066] 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 central tubular. 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.

[0067] If the initial configuration and the final configuration of the device are assumed to be known (i.e., the position of the rotor 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 central tubular. The motor can then be operated to cause the rotor to perform the determined number of revolutions.

[0068] If the initial configuration of the device is not known (i.e. the position of the rotor 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 rotor reaching either of the ends of its threaded connection with the central tubular. The position of the rotor in the device then becomes known, and the number of revolutions required to transition to the final configuration can be determined, as described above.

[0069] 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 rotor 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.

[0070] The inflow control device of Figure 1A, 1 B, and 1C is particularly advantageous because of its compact design - it includes a single moving part (the rotor). The inflow control device from Figure 1A, 1 B, and 1C is shown in plan-view in Figure 3. The plan-view shows a cross section of the enclosure 102, central tubular 108, rotor 112 with inner portion 112a and outer portion 112b, permanent magnets 122, and induction coils 124, which are contained in the lateral walls of the enclosure 102. The permanent magnets 122 are shown as being rectangular in cross section in Figure 3. Other shapes in cross section, such as circles, ellipses, or other quadrilaterals for the permanent magnets, are, however, possible. The enclosure, 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 is able to freely rotate within the enclosure.

[0071] In the specific example shown, the inflow control device comprises a three phase motor arrangement 300. The three phase motor arrangement includes a rotor 212 with six permanent magnets 122, and nine induction coils 124. The permanent magnets and induction coils are circumferentially arranged around the rotor and the device enclosure 102, 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 4A to 4C, 5A to 5C, 6A to 6B, and 8A to 8B (and the variants thereof) may also incorporate the motor arrangement from Figure 3.

[0072] Figure 4A, 4B and 4C are transverse cross sections of an inflow control device 400 in an open, a choke, and a closed configuration, respectively.

[0073] The inflow control device 400 is a variant of the inflow control device from Figures 1A, 1 B, and 1C, which includes a central tubular without perforations 110 for providing fluid ingress into the device. The central tubular is also closed off at its proximal end so that fluid cannot pass into it from the proximal side of the device (as was the case in the embodiments illustrated in Figures 1A to 1C). While the inflow control device 400 is shown to include a central tubular 308, it will be understood that this tubular may instead be a central axle, which need not be hollow.

[0074] In the open and choke configurations, the inflow control device of Figure 4A to 4C defines a single type of passage for fluid to flow from the inlet to the outlet, namely: a passage through the one of the openings in the proximal wall of the device, through the one of the one or more ports 128 defined through the rotor, between the distal face of the rotor and the distal wall of the enclosure, and then through to one of the one or more openings in the distal wall of the device.

[0075] The remaining features of the device and its operation are as described in relation to Figure 1A, 1 B, 1C, and 2.

[0076] Figure 5A, 5B and 5C are transverse cross sections of an inflow control device 500. The device 500 is in a closed configuration in both Figures 5A and 5C, and in an open / choke configuration in Figure 5B.

[0077] The inflow control device 500 is a variant of the inflow control devices from Figures 4A, 4B, and 4C, in which the one or more ports 528 through the rotor 112 (i.e. the valve body) are misaligned with the openings (i.e. inlet 504) defined in the proximal enclosure wall such that, when the rotor 112 sealingly engages with the distal enclosure wall, fluid is prevented from passing from the inlet 504 to the outlet 106. As a result, the device defines two closed configurations, with the “open” and “choke” configurations therebetween. This arrangement facilitates faster switching from open to closed configurations - as the linear travel of the rotor between closed positions within the device is halved. In some embodiments (not shown), the device 500 may include the central tubular 108 with perforations 110 from Figures 1A to 1C. Such an inflow control device would then be in an open configuration in Figure 5A but only permitting flow of fluid through the second type of fluid passage. As the rotor moves distally, the flow rate through the device would then increase, before beginning to decrease after the valve body begins to obstruct the perforations 110, and then reducing to zero rapidly as the valve body establishes contact with the inner-facing distal face of the enclosure.

[0078] In a variant of the inflow control device 500 (not shown), the distal enclosure wall includes a landing arrangement (i.e. a valve seat) in order to space apart the rotor / valve body and the distal enclosure wall in the closed configuration. In these variants, the outlet 106 is arranged to extend radially into the lateral wall of the enclosure and at a position that allows the rotor / valve body to sealingly engage against the outlet (i.e. spaced from the distal wall by at least the gap between the rotor and the distal enclosure wall), as shown in Figures 5A to 5C. As a result, fluid can be present on opposing sides of the valve body and the valve body remains substantially pressure balanced, while ensuring that the outlet is closed when the valve body contacts the landing arrangement. This prevents the formation of a vacuum layer beneath the valve body in the closed position, which could inhibit subsequent opening of the device. It also ensures that any pressure difference, which exists between the inlet and outlet (i.e. between formation and within the base string) does not prevent the valve body from moving away from its closed position or otherwise moving. In a specific example, the landing arrangement comprises a plurality of pins upon which the valve body sits in its closed position.

[0079] The remaining features of the device and its operation are as described in relation to Figures 1A, 1 B, 1C, and 2.

[0080] Figures 6A and 6B are transverse cross sections of an inflow control device 600 in an open and a closed configuration, respectively. Although not shown, the inflow control device 600 defines a plurality of choke configurations between the open and closed configurations shown in Figures 6A and 6B.

[0081] The inflow control device 600 is an alternative embodiment to the inflow control device 100 of Figures 1A to 1C. The principle difference between the embodiment of Figures 1A to 1C and the embodiment illustrated in Figure 6A and 6B is that, in Figure 6A and 6B, the valve body 616 and rotor 612 are separate components, the central tubular 608 is rotationally coupled to the enclosure 602 via bearings 614a, 614b, and one or more guide rails 618 are provided through a respective one of the one or more ports 628 through the valve body 616.

[0082] In more detail, the inflow control device 600 includes an enclosure 602, which defines an inlet 604 for fluid entry, an outlet 606 for fluid exit, and which includes a central tubular 608 (i.e., a hollow axle) with a perforated portion 610. The device also includes a rotor 612 and a valve body 616. The valve body defines one or more through ports 628, through which a respective guide rail 618 extends. There may, therefore, be one or more guide rails 618. The ports 628 are greater in extent than the guide rail such that, with the guide rails extending therethrough, the ports permit the flow of fluid therethrough. The guide rail 618 is fixedly coupled to the enclosure of the device (e.g., at its proximal and distal ends). The perforated portion may comprise one or more openings in the central tubular. The central tubular is rotationally coupled to the enclosure, for example, via bearings 614a, 614b at the proximal and distal ends of the tubular, to allow relative rotation therebetween. In some embodiments (not shown), one or more further ports are provided through the valve body and through which there are no guide rails. These one or more further ports increase the maximum possible flow rate of fluid through the device in the open configuration.

[0083] Similar to Figure 1A to 1 C, the inlet 604 comprises (i) a plurality of openings defined in a proximal wall of the enclosure and (ii) the perforated portion 610. The outlet comprises one or more openings through the distal wall of the enclosure. In some examples, a nozzle 626 is provided in the proximal end of the central tubular. The opening defined by the nozzle may also be regarded as forming part of the inlet 104 for fluid entry.

[0084] In the open (Figure 6A) and choke configurations (not shown), the valve body 616 permits two types of passage for fluid flow through the device, from the inlet to the outlet. The first passage is through the one of the openings in the proximal wall of the device, around a periphery of the rotor, through the one of the one or more ports 628 defined through the valve body and through which guide rails 618 may extend, between the distal face of the valve body and the distal wall of the enclosure, and then through to one of the one or more openings in the distal wall of the device. The second passage is through the perforated portion 610 of the central tubular 608, between the distal face of the valve body and the distal wall of the enclosure, and then through to one of the one or more openings in the distal wall of the device.

[0085] In the closed configuration (Figure 6B), the valve body 616 obstructs both the first and second fluid passage types. The first passage type is obstructed by bringing the valve body into sealing engagement with the outlet 606 and / or bringing the valve body into sealing engagement with the inner-facing distal wall of the enclosure. The second passage type is obstructed by the valve body as it travels along its threaded connection with the central tubular 608 to thereby sealingly engage against the perforated portion 610.

[0086] In some embodiments (not shown), the distal enclosure wall includes a landing arrangement in order to space apart the valve body and the distal enclosure wall in the closed configuration. As a result, fluid can be present on opposing sides of the valve body and the valve body remains substantially pressure balanced. This prevents the formation of a vacuum layer beneath the valve body in the closed position, which could obfuscate subsequent opening of the device. In such embodiments, the outlet 606 is arranged to extend radially into the lateral wall of the enclosure and at a position that allows the valve body to sealingly engage against the outlet (i.e. spaced from the distal wall by at least the gap between the valve body and the distal enclosure wall). In a specific example, the landing arrangement comprises a plurality of pins upon which the valve body sits in its closed position.

[0087] The rotor is fixedly coupled to the central tubular 608. As has been noted above, the central tubular is rotationally coupled to the enclosure. This means that rotation of the rotor causes the rotor and the central tubular to, collectively, rotate about the central axis of the device enclosure. The tubular defines a notional rotor axis that is coincident with the orientation axis of the tubular.

[0088] The valve body 616, on the other hand, is threadedly coupled to the central tubular 608 but it cannot freely rotate, with the central tubular 608 and rotor 612, relative to the enclosure due to the one or more guide rails 618a, 618b. However, rotation of the central tubular 608 causes the valve body to travel along its threaded connection with the tubular 608 within the device. The use of more than one guide rail helps ensure that the valve body remains level (i.e. restrict tilting of the valve body) within the device, as it travels along the threaded connection with the central tubular, during operation.

[0089] The device further comprises a motor, which is made up of a rotor 616, one or more induction coils 624, and one or more permanent magnets 622, which are provided in the rotor. In some examples, the induction coils 624 are provided within or around the proximal wall of the enclosure (either within the device or outside of it). The permanent magnets may be arranged in the rotor in a position substantially beneath the induction coils to promote stronger magnetic responses. To further improve induction, the inflow control device may be made up of a soft magnetic material (e.g., iron). The motor arrangement may be substantially as described above, with reference to Figures 1A to 1C and Figure 3, but with the induction coils 624 and permanent magnets 622 being located along a common axis, coincident with the rotor axis.

[0090] Analogous to Figures 4A to 4C and Figures 1A to 1 C, the inflow control device 600 may, in a variant, be without a central tubular 608 (with its perforations 610) for providing fluid ingress into the device. This variant is not shown. The central tubular may instead be closed off at its proximal end so that fluid cannot pass into it from the proximal side of the device (as was the case in the embodiments illustrated in Figures 6A to 6B). Alternatively, in a variant of the inflow control device 600, the central tubular 608 is replaced with a central axle, which need not be hollow. Such a variant defines a single type of passage for fluid to flow from the inlet to the outlet, namely: a passage through the one of the openings in the proximal wall of the device, around a periphery of the rotor, through the one of the one or more ports 628 defined through the valve body and through which guide rails 618 may extend, between the distal face of the valve body and the distal wall of the enclosure, and then through to one of the one or more openings in the distal wall of the device.

[0091] Operation of the inflow control device of Figure 6A and 6B is now described with reference to the method flow diagram of Figure 7.

[0092] In step 702, the motor 620 is powered to causes the rotor and the central tubular 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 is a three-phase motor to drive smoother rotation.

[0093] As the central tubular rotates relative to the valve body, the valve body is caused to advance, in step 704, along the rotor axis towards the perforation portion 610 and the distal enclosure wall. Step 702 continues until it is determined that the inner radial portion of the valve body obstructs the perforated portion and the valve body establishes sealing contact with the outlet, at its closed position.

[0094] Similarly, the inflow control device 600 can be operated to transition from the closed to the open configuration by powering the motor, as in step 702, to cause the rotor to rotate in the opposite direction compared with the method of Figure 7. This causes valve body to advance away from the perforated portion of the central tubular and out of sealing contact with the outlet. As with Figure 7, the motor can be powered until it is determined that the valve body no longer obstructs the perforated portion and outlet.

[0095] It will be understood that the device can be operated to transition between a closed and open, choke and closed, and between different choke configurations, substantially as described in relation to Figure 2 (but with the central tubular and rotor rotating together rather than the valve body rotating about the central tubular).

[0096] Figure 8A and 8B are transverse cross sections of an inflow control device 800 in an open, and a closed configuration, respectively. Although not shown, the inflow control device 800 defines a plurality of choke configurations between the open and closed configurations shown in Figures 8A and 8B.

[0097] The inflow control device 800 is a variant of the inflow control device from Figures 6A and 6B, in which the guide rails 818a, 818b are fixedly coupled at one end to the distal wall of the device enclosure and at an opposing end to a dividing wall or partition 830. Each of the rotor and the valve body include one or more (further) ports 828a, 828b respectively, and permit therethrough the flow of fluid between the inlet and outlet. As illustrated, the respective ports are preferably aligned (with respect to the rotor axis) but this is not essential. In some examples, the ports of the valve body and rotor are not so aligned. The additional ports through the rotor and valve body increase the maximum possible flow rate of fluid through the device, compared with the embodiment of Figure 6A and 6B. In some embodiments (not shown), the guide rails 818a, 818b are fixedly coupled to the device enclosure at one end only.

[0098] In the open (Figure 8A) and choke configurations (not shown), the valve body 816 permits two types of passage for fluid flow through the device, from the inlet to the outlet. The first passage is through the one of the openings in the proximal wall of the device, through the one of the one or more ports 828a, 828b defined through the rotor and the valve body, between the distal face of the valve body and the distal wall of the enclosure, and then through to one of the one or more openings in the distal wall of the device. To a limited extent in comparison, this passage also includes the flow of fluid from the rotor ports through the ports in the valve body through which the guide rails extend. The second passage is through the perforated portion 810 of the central tubular 808, between the distal face of the valve body and the distal wall of the enclosure, and then through to one of the one or more openings in the distal wall of the device.

[0099] In the closed configuration (Figure 8B), the valve body 816 obstructs both the first and second fluid passage types. The first passage type is obstructed by bringing the valve body into sealing engagement with the outlet 806 and / or bringing the valve body into sealing engagement with the inner-facing distal wall of the enclosure. The second passage type is obstructed by the valve body at it travels along the thread to sealingly engage against the perforated portion 810.

[0100] The remaining features of the device and its operation are as described in relation to Figure 6A, 6B and 7.

[0101] Analogous to Figures 4A to 4C and Figures 1A to 1 C, the inflow control device 800 may, in a variant, include a central tubular 808 without perforations 810 for providing fluid ingress into the device. This variant is not shown. The central tubular may then be closed off at its proximal end so that fluid cannot pass into it from the proximal side of the device (as was the case in the embodiments illustrated in Figures 8A to 8B). Alternatively, in a variant of the inflow control device 800, the central tubular 808 is replaced with a central axle, which need not be hollow. This variant is less prone to washouts as a greater area is available for the openings defined in the proximal or distal walls of the inflow control device than for the perforations of the central tubular (without causing unacceptable weakening of the device). Such a variant defines a single type of passage for fluid to flow from the inlet to the outlet, namely: a passage through the one of the openings in the proximal wall of the device, through the one of the one or more ports 828a, 828b defined through the rotor and valve body, between the distal face of the valve body and the distal wall of the enclosure, and then through to one of the one or more openings in the distal wall of the device. To a limited extent in comparison, fluid may also pass from the one or more ports 828a through the rotor through the ports through which the guide rails 818a, 818b extend.

[0102] In the specific examples illustrated in Figures 6A to 6B and 8A to 8B, the openings providing the outlet are shown to traverse radially into and through the lateral wall of the enclosure. Such an outlet may be referred to as a “radial” outlet. Alternatively (not shown), the openings include a distally extending portion only, provided that the ports 628, 828 through the valve body are out of alignment with these openings, when the valve body is in the closed position (i.e. , in sealing contact with the distal wall of the enclosure), such that fluid is prevented from passing through the valve body and out from the outlet. Alternatively (not shown), the openings forming the outlet can traverse into the lateral wall of the enclosure, before passing through the distal wall of the enclosure (as shown in Figures 1A to 1 C, for example). In the embodiments described above, the inflow control devices are shown in transverse cross section. In plan-view, the ports through the valve body, rotor, and the openings in the enclosure wall which constitute the inlet and outlet may be circular, square, rectangular or other shape. The inlet openings and the ports through the rotor and / or valve body may be shaped so as to extend at least partially circumferentially about the rotor axis. This is particularly beneficial as it ensures that, even if the valve body and / or rotor rotates relative to the enclosure, the ports and inlet openings will overlap (i.e. remain aligned).

[0103] Figure 9 is a transverse cross section of an inflow control device 900 in an open, choke, and a closed configuration (from top to bottom). The inflow control device 900 is similar to the inflow control device from Figure 1A to 1 C, but having openings 906a defined in the distal wall of the enclosure rather than the proximal wall (although openings in the proximal wall, either in combination with, or instead of, these openings 906a may be present in other variants). The one or more ports 928 through the rotor ensure that, in use, fluid is present on opposing sides of the rotor. As has already been mentioned, this advantageously ensures the rotor is pressure balanced in use.

[0104] As with Figure 1A to 1C, the inflow control device 900 includes an outlet 906b that extends radially into, and axially through, the lateral wall of the enclosure. But, unlike Figure 1A to 1 C, the outlet 906a is arranged relative to the perforated portion 110 such that, as the rotor 112 moves from its closed to open positions, it sealingly closes the outlet 906a before the perforated portion 110. In Figure 1 B, the perforated portion 110 is sealingly closed before the outlet 106. That is, the centre position of the portion of outlet 906a that extends radially into the lateral wall of the enclosure is closer to the proximal wall of the enclosure than the centre position of the perforated portion.

[0105] As a result, the flow rate through the inflow control device 100, 900 for equivalent rotor positions can be made to be different. If the flow rate through the perforated portion 110 is less than the outlet 106, 906a, then the flow rate for the inflow control device 900 initially decreases (more) sharply and then (more) gradually from the open to the closed position. The remaining features of the device 900 and its operation are as described in relation to Figure 1A, 1 B, 1C, and 2.

[0106] In general, perforated portion 110 and outlet 906b may be positioned with respect to each other such that, as the rotor transitions from its open to closed position:

[0107] • the rotor becomes sealingly engaged with the perforated portion before the outlet 906b (or vice versa); and / or

[0108] • the rotor completely covers the perforated portion before the outlet 906b (or vice versa).

[0109] As the axial length of the perforated portion 110 and outlet 906a may differ (e.g., the perforated portion may be longer), it is also possible that the rotor sealingly engages with the perforated portion before the outlet but still completely covers the outlet before completely covering the perforated portion (or vice versa).

[0110] As a result, by selecting different size, number, and relative position combinations of the perforated portion 110 and the outlet 906a, the flow rate through the inflow control device for any given rotor position can be tailored according to the needs of the system.

[0111] Figure 10 is a transverse cross section of an inflow control device 1000 in an open, choke, and a closed configuration (from top to bottom). The inflow control device 900 is equivalent to the inflow control device from Figure 1A to 1C but with the direction of fluid flow reversed. The remaining features of the device 1000 and its operation are as described in relation to Figure 1A, 1 B, 1 C, and 2. As has already been noted, the inlet and outlet described in relation to the other embodiments are interchangeable as they depend on the fluid flow through the device, rather than any feature inherent to the device itself.

[0112] Figure 11 is a schematic illustration of a section 1100 of a producing interval in a completed well. The completed well extends through a hydrocarbon reservoir 1102. The section comprises a base string 1104 arranged to transport production fluids to the surface, a screen 1106 configured to block particulates (such as sand) and one or more inflow control devices 1108 configured to control the inflow of fluid from the reservoir. The inflow control device 1108 in Figure 11 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 not 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 to 1 C, 4A to 4C, 5A to 5C, 6A to 6B, 8A to 8B, 9, 10 and the variants described above. In some embodiments, 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 a producer or an injector in an injector well. This can be achieved, for example, by installing the inflow control device in a screen section in the opposite or reverse orientation such that the outlet is the proximal portion and the inlet is the distal portion. Gas or water injection operations are known to the skilled reader, per se.

[0113] When the pressure of the reservoir 1102 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 1108 via one or more channels defined within the base string wall. The arrows in Figure 11 denote the direction of fluid flow. Each inflow control device 1108 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).

[0114] Figure 12 is a schematic illustration of a producing interval 1200 of a completed well located within a reservoir. The interval 1200 contains four zones. Each zone is separated by a zonal isolation element 1202, 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 1204. 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 1106, and each screen may be associated with one or more inflow control devices.

[0115] 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 1106, 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.

[0116] In the specific example shown in Figure 12, the zone 1204 comprises one section of base string, and each zone comprises one screen 1106, which allows fluid to flow from the reservoir into the base string 1104 via one inflow control device. In general, each zone 1204 includes one or more screens 1106 and the or each screen includes one or more inflow control devices. In a specific example, there are 10 sand screens 1106 per zone and each screen includes 3 inflow control devices. A signal cable 1208 is arranged in an annulus surrounding the base string. The signal cable provides power to the inflow control devices 1108 and their circuitry 1210 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 wrapping of the screens themselves.

[0117] 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 central tubular, 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.

[0118] 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.

[0119] Throughout the description, like reference numerals have been used to describe like features from different embodiments.

[0120] Variants of the embodiments described above are envisaged.

[0121] In any embodiment having a fluid passageway and an inlet provided by one or more openings in the proximal wall of the device (e.g., as with Figure 6A, 6B, 8A, 8B, 10), the fluid passageway may be replaced with a central axle absent any perforations.

[0122] In any embodiment, the inlet and outlet may comprise a channel that extends radially and / or axially through the lateral, proximal and / or distal wall of the device. An axial inlet through the distal wall of the device is shown in Figure 8A, 8B. A radial outlet through the lateral wall is shown in Figures 6A, 6B, 8A and 8B. An outlet that extends radially into the lateral wall and then axially through the lateral wall and the distal wall is shown in Figures 1A to C, 4A, 4B, 5A to C, 9 and 10.

[0123] With any of the aforementioned embodiments that includes an outlet extending through the lateral wall of the enclosure (i.e. an outlet comprising one or more openings extending radially outward), the device may include a landing arrangement arranged at the distal enclosure wall in order to space apart the rotor / valve body and the distal enclosure wall in the closed configuration. As a result, fluid can be present on opposing sides of the valve body and the valve body remains substantially pressure balanced. This prevents the formation of a vacuum layer beneath the valve body in the closed position, which could obfuscate subsequent opening of the device. It also ensures that any pressure difference, which exists between the inlet and outlet (i.e. between formation and within the base string) does not prevent the valve body from moving away from its closed position or otherwise moving. In a specific example, the landing arrangement comprises a plurality of pins upon which the valve body sits in its closed position.

[0124] For example, while the valve body and rotor shown in the embodiments of Figures 1A to 1 C, 4A to 4C, 5A to 5C and the valve body in the embodiments of Figures 6A to 6B and 8A to 8B sealingly engage against the inner edge of the lateral wall of the inflow control devices in order to close the outlets provided in the lateral wall of the inflow control device in their respective closed positions, this need not be the case. The rotor and / or valve body may have a lateral extent (e.g., a radius) less than the lateral extent of the space (e.g., radius) defined within the device enclosure, and further, the rotor and / or valve body may include no ports. Fluid may then flow around the rotor and / or valve body from inlet to outlet. The outlet are then provided by one or more openings through the distal wall of the device enclosure from a position inward of the valve body (i.e. close enough to the rotor axis that the valve body can cover them), such that, the valve body, when it contacts the distal wall of the enclosure, is able to close the outlet.

[0125] Operation of such a device includes powering a motor to rotate the rotor of the inflow control device to thereby cause the valve body to advance into or out of a position within the device in which the valve body obstructs free passage of fluid between the inlet and outlet; and, by consequence, causing fluid flow, from the one or more openings through one of the two opposing enclosure walls and / or the lateral wall to the outlet, to be obstructed (i.e. the valve body is advanced into a closed position) or permitted (i.e. the valve body is advanced out from the closed position into an open position, respectively.

[0126] The outlet in each of the aforementioned embodiments may also be provided through the distal wall of the enclosure (e.g., the one or more openings are arranged coincident to the rotor axis). Such an outlet may be referred to as an “axial” outlet. This is a particularly useful configuration of the device, since then the outlet of the device can be made (more) flush with the internal diameter of the base string of wellbore, following installation. This makes mechanical interventions, such as wireline operations, easier, and reduces the effect of the inflow control devices on the flow of fluid through the base string. As a result, the configuration of the outlet 106 shown in Figures 1 , 4,5, 9, and 10 is preferred to the configuration of the outlet in Figures 6 and 8. As has been noted, the embodiments (and variants thereof) shown in Figures 6 and 8 may additionally or alternatively include axial outlets.

[0127] The inlet and outlets may be alternatively or additionally provided in the lateral wall of the enclosure. The perforated portion of the central tubular may, alternatively or additionally, be positioned at the proximal end of the device, as opposed to being positioned in the distal end, as shown in the illustrated embodiments. If the central tubular comprises more than one (separate) perforated portion at different locations within the device, it is possible to define multiple “closed” configurations and multiple “choke” configurations of the same choking strength.

[0128] While the valve body has been shown as being threadedly coupled to the central axle in the illustrated embodiments, it will be understood that the valve body may be threadedly coupled to a sleeve which is arranged around the central axle instead. The sleeve may also define a perforated portion to define a fluid pathway into the device.

[0129] In some embodiments (not shown), the inflow control device 800 includes a gear system which is rotationally couples the portions of the device separated by partition 830. The gear system allows control of 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). The mechanical advantage can either be greater than 1 (the gear ratio is less than 1 such that the valve body rotates at a lower angular velocity than the rotor) or less than 1 (the gear ratio is greater than 1 such the valve body rotates at a greater angular velocity than the rotor). A gear system is also possible with the embodiments of Figures 1 , 4, and 5, with the gear system rotationally coupling the inner and outer portions of the rotor. Example gear systems include the epicyclic gear system, which are described in detail at page 18, lines 14 to 27 and Figure 7 of Research Disclosure no. 719043, which is incorporated herein by reference.

[0130] 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; and a valve body comprising at least one port through the valve body, wherein rotation of the rotor is arranged to cause the valve body to advance towards or away from a position wherein the device defines a pathway for fluid to pass between the inlet and the outlet via said at least one port through the valve body.

2. An inflow control device, comprising: an inlet for fluid ingress; an outlet for fluid egress; a rotor operable to rotate about a rotor axis; and a valve body, wherein rotation of the rotor is arranged to cause the valve body to advance towards or into a position within the device in which the valve body obstructs free passage of fluid between the inlet and outlet, wherein, the inflow control device comprises two opposing enclosure walls and a lateral wall extending therebetween, and the inlet comprises one or more openings through one of the two opposing enclosure walls and / or the lateral wall and through which fluid is able to pass into the inflow control device, and wherein, in an open position, the valve body defines a pathway with the lateral wall for fluid to pass between the inlet and the outlet.

3. An inflow control device according to claim 1 , in which rotation of the rotor is arranged to cause the valve body to advance from (i) a position within the device in which fluid is obstructed from passing between the inlet and outlet via said at least one port through the valve body, to (ii) a position within the device in which fluid is able to pass between the inlet and outlet via said at least one port through the valve body.

4. An inflow control device according to claims 1 or 3, wherein the inflow control device comprises two opposing enclosure walls and a lateral wall extending therebetween, and the inlet comprises one or more openings through one of the twoopposing enclosure walls and / or the lateral wall, and through which fluid is able to pass into the inflow control device.

5. An inflow control device according to any one of claims 1 to 4, wherein the rotor is the valve body.

6. An inflow control device according to any one of claims 1 , 3 and 4, comprising one or more guides rails extending through a respective one of the one or more ports through the valve body.

7. An inflow control device according to claim 6, wherein the valve body comprises one or more further ports.

8. An inflow control device according to claims 6 or 7, wherein the rotor comprises one or more openings through the rotor.

9. An inflow control device according to any one of the preceding claims, in which the outlet comprises one or more openings, each or the opening extending axially through an enclosure wall of the inflow control device and through which fluid is able to pass out from the inflow control device.

10. An inflow control device according to any one of the preceding claims, in which the inlet comprises one or more openings, each or the opening extending axially through an enclosure wall of the inflow control device and through which fluid is able to pass into the inflow control device.

11. An inflow control device according to any one of the preceding claims, in which the outlet comprises one or more openings, each or the opening extending radially through a lateral enclosure wall of the inflow control device and through which fluid is able to pass out from the inflow control device.

12. An inflow control device according to any one of the preceding claims, in which the inlet comprises one or more openings, each or the opening extending radially through a lateral enclosure wall of the inflow control device and through which fluid is able to pass into the inflow control device.

13. The inflow control device according to any one of claims 9 to 12, in which the valve body is positionable within the device so as to sealingly engage with the or each opening of the inlet and / or outlet so as to prevent fluid from passing into and / or out of the device.

14. An inflow control device according to claim 9 or 10, wherein, in a closed configuration of the device, the one or more ports of the valve body and the or each opening of the outlet are misaligned and the valve body is positioned to sealingly engage with the enclosure wall through which the or each opening of the outlet extend, to thereby prevent fluid passing from out of the device.

15. An inflow control device according to any one of claims 1 and 3 to 14, in which any one of the following are circumferentially shaped about the rotor axis: the one or more ports of the valve body; the one or more ports of the rotor; and the one or more openings of the inlet.

16. An inflow control device according to any one the preceding claims, 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.

17. A method of operating the inflow control device according to any one of claims 1 , 3 to 16, the method comprising: powering a motor to rotate the rotor of the inflow control device to thereby cause the valve body to advance into or out from a position within the device in which fluid is able to pass between the inlet and the outlet via the at least one port through the valve body.

18. A method of operating the inflow control device according to any one of claims 2, 5, 9 to 14, and 16, when dependent on claim 2, the method comprising: powering a motor to rotate the rotor of the inflow control device to thereby cause the valve body to advance into or out from a position within the device in which the valve body obstructs free passage of fluid between the inlet and outlet via the pathway between the lateral wall and the valve body; andthereby causing fluid flow, from the one or more openings through one of the two opposing enclosure walls and / or the lateral wall to the outlet, to be obstructed or permitted.

19. A wellbore system, comprising: a base string arranged to transport production fluids; one or more inflow control devices according to any of claims 1 to 16, 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 16 as an injector in a wellbore system.

21. Use of the inflow control device according to any one of claims 1 to 16 as a production fluid intake device in a wellbore system.

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