TURBINE

Abstract

A turbine for use in extracting energy from fluid flowing along a fluid channel defines a portion of the fluid channel and includes a flow pathway in communication with the fluid channel. A moveable element, such as a rotor, is disposed around the fluid channel and is moveable under the action of fluid flowing along the flow pathway so as to extract energy therefrom. The turbine may be associated with other apparatus in the fluid system, and may be capable of storing extracted energy for later use.

Claims

1. A turbine for extracting energy from fluid flowing along a fluid channel, the turbine defining a portion of the fluid channel, and comprising; a flow pathway in communication with the fluid channel; and a moveable element disposed around the fluid channel, in the flow pathway; the moveable element moveable under the action of fluid flowing along the flow pathway so as to extract energy therefrom.

2. The turbine according to claim 1, wherein the flow pathway is separated from the fluid channel, along at least a part of its length.

3. The turbine according to claim 2, wherein the flow pathway comprises one or more inlets in communication with the fluid channel and/or one or more outlets in communication with the fluid channel.

4. The turbine according to claim 1, wherein the flow pathway is disposed around the fluid channel.

5. The turbine according to claim 1, wherein the flow pathway is annular, along at least a part of its length.

6. The turbine according to claim 1, wherein the moveable element comprises a rotor.

7. The turbine according to claim 6, wherein the rotor comprises one or more rotor blades.

8. The turbine according to claim 7, wherein the rotor blades are helically arranged around the axis of rotation of the rotor.

9. The turbine according to claim 7, wherein the rotor blades extend from a circumferential structure.

10. The turbine according to claim 1, comprising a stator disposed around or against the fluid channel.

11. The turbine according to claim 10, comprising an electrical rotor and stator, wherein the stator comprises one of a permanent magnet and a conductive coil and the rotor comprises the other of the permanent magnet and the conductive coil.

12. The turbine according to claim 10, wherein the stator extends around and/or against the moveable element.

13. (canceled)

14. (canceled)

15. The turbine according to claim 1, comprising a circumferential recess, wherein at least a part of the moveable element is located within the circumferential recess.

16. (canceled)

17. The turbine according to claim 1, wherein the flow pathway is separated from the fluid channel along at least a part of its length, and the turbine is configured to selectively receive fluid into the flow pathway.

18. The turbine according to claim 17, wherein the flow pathway is provided with a flow control arrangement.

19. The turbine according to claim 18, wherein the flow control arrangement is responsive to variations in flow or fluid conditions including at least one of variations in pressure/flow rate, variations in composition or phase, and variations in the direction of fluid flow.

20. The turbine according to claim 18, comprising a control unit operable to actuate the flow control arrangement.

21. The turbine according to claim 20, wherein the control unit comprises a processor operable to receive and respond to a control signal.

22. The turbine according to claim 1, configured to function as a sensor.

23. (canceled)

24. Use of a turbine according to claim 1 as a sensor, to measure one or more fluid properties, or changes thereof.

25. Apparatus for use in a fluid flow system, comprising; a body defining a fluid channel; and a turbine according to claim 1 coupled to the body and defining a portion of the fluid channel.

26. The apparatus according to claim 25, wherein the turbine is adapted to be secured to the body.

27. The apparatus according to claim 26, wherein the turbine forms part of a mandrel, adapted to be secured around a tubular.

28. (canceled)

29. A method for extracting energy from fluid flowing along a fluid channel, comprising; providing a turbine which defines a portion of the fluid channel, and which comprises a flow pathway in communication with the fluid channel passing fluid from the fluid channel along the flow pathway; and moving a moveable element which is disposed around the fluid channel, in the flow pathway, under the action of the fluid flowing along the flow pathway so as to extract energy therefrom.

30. The method according to claim 29, wherein the flow pathway is separated from the fluid channel, along at least a part of its length, and the method comprises passing fluid from the fluid channel into the flow pathway, along the flow pathway and back into the fluid channel.

31. The method according to claim 29, comprising rotating a rotor disposed in the flow pathway around the fluid channel, under the action of the fluid flowing along the flow pathway.

32. The method according to claim 29, comprising operating a flow control arrangement so as to vary the flow of fluid along the flow pathway.

33. The method according to claim 29, comprising using the turbine to detect a fluid property or a change in a fluid property.

34. (canceled)

35. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0135] These and other aspects will now be described, by way of example only, with reference to accompanying drawings, in which:

[0136] FIG. 1 is a cut-away view of a turbine;

[0137] FIG. 2 shows a flow chart of the operation of the turbine of FIG. 1;

[0138] FIG. 3 shows a cut-view of another embodiment of a turbine, comprising an energy storage arrangement;

[0139] FIG. 4 shows a cut-view of another embodiment of a turbine, comprising an energy storage arrangement and an energy generator;

[0140] FIG. 5 shows a flow chart of the operation of the turbines of FIGS. 3 and 4;

[0141] FIG. 6 shows a cut-view of another embodiment of a turbine, comprising a mechanical energy storage arrangement;

[0142] FIG. 7 shows a cut-view of another embodiment of a turbine, comprising a flow path which is separate from the fluid channel;

[0143] FIG. 8 shows a schematic cross sectional view of another embodiment of a turbine, comprising a Hall sensor and an inflow control arrangement; and

[0144] FIG. 9 shows a schematic side view of a turbine and an inflow control device on a work string.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0145] FIG. 1 shows a turbine 10 in accordance with an embodiment of the invention. The turbine 10 is configured to extract energy from fluid flowing along a fluid channel 11. The turbine defines a portion 12 of the fluid channel. A moveable element, in the embodiment shown a rotor 14, is disposed around the fluid channel 11 (and in particular the portion 12 defined by the turbine). A flow pathway 16, forming part of the periphery of the fluid channel, extends through the rotor blades 18. Thus, the flow pathway is in communication with the fluid channel and the moveable element 14 is disposed in the flow pathway 16 around the fluid channel 11, 12.

[0146] The turbine 10 is provided within a portion of a tubular 22.

[0147] The moveable element 14 is moveable under the action of fluid flowing along the flow pathway 11, 12 so as to extract energy therefrom. For example, energy may be extracted from a flow of fluid produced from a subterranean formation and/or a flow of fluid injected into a work string, which may be a production or injection tubing string, or at the wellhead and associated pipework. Indeed the turbine may be used to extract energy from any flow of fluid along a fluid channel, and may be employed for example in water or hydrocarbon distribution pipelines, chemical production and refining and the like.

[0148] The rotor comprises a circumferential structure 20, and the rotor blades 18 extend inwardly from the circumferential structure 20. The rotor blades are arranged generally helically, so that they are at an angle in relation to fluid flowing along the fluid channel. Thus, when fluid passing along the flow pathway 16 impinges a rotor blade 18, a component of force is transmitted rotationally (anticlockwise in the embodiment shown). Should the flow of fluid be reversed, so too would the direction of rotation.

[0149] The rotor 14 is recessed within a circumferential channel 24 in the body 26 of the turbine, such that only the blades 18 extend into the flow pathway. Thus the turbine results in a minimal reduction in the flow area of the flow pathway.

[0150] The turbine 10 further comprises a bearing 28 between the rotor 14 and the base of the channel 24. In the embodiment shown, the bearing is a roller bearing, however other types of bearing, such as a fluid bearing a magnetic bearing, or a bushing, may be used. Accordingly, the channel 24 restricts axial motion of the rotor 14, and the bearing 28 facilitates low-friction rotational motion of the rotor.

[0151] Also mounted around each side of the circumferential structure 20 are permanent magnets 21.

[0152] The turbine 10 includes a stator 30, in the form of an annular array of electrical coils within the body/housing 26 of the turbine, to either side of the rotor 16 and thus adjacent to the magnets 21. Accordingly, in use, movement of the movable element (rotation of the rotor 16) causes an electromotive force to be induced in the stator 30. i.e. Kinetic energy from the fluid flow is converted into electrical energy, which may be stored (for later use to power other components) and/or used directly to power other components (not shown)—as shown in the flow chart of FIG. 2.

[0153] FIG. 3 shows an alternative embodiment of a turbine 110 in accordance with the invention. Features in common with turbine 10 are provided with like reference numerals, incremented by 100.

[0154] The turbine 110 comprises a mandrel 132, in which is housed an energy storage arrangement 134. The energy storage arrangement 134 comprises an electric pump 136 operable to charge fluid accumulators 138 with a pressurized fluid. The pressurized fluid may be fluid diverted from the fluid channel, or fluid diverted from outside of the mandrel (e.g. a wellbore fluid), via fluid conduits (not shown).

[0155] The pressurized fluid may be stored and released at a later time, to power pneumatic or, more typically, hydraulic apparatus connected to the energy storage arrangement. The turbine may also be configured to charge and release pressurized fluid at the same time. For example, the pump may be operable to charge some of the accumulators 138, whilst one or more other accumulators are being discharged.

[0156] In alternative embodiments (not shown) the energy storage arrangement may comprise an electrical cell or battery, which may be charged by current induced in the stator.

[0157] FIG. 4 shows another embodiment of a turbine 210 in accordance with the invention. Features in common with turbine 10 are provided with like reference numerals, incremented by 200. Features in common with turbine 110 are provided with like reference numerals, incremented by 100.

[0158] The turbine 210 includes an energy storage arrangement 234 in which the accumulators 238 are coupled to electric generators 240.

[0159] The turbine 210 is used to extract and store energy in the accumulators 238 in the form of fluid pressure potential energy, in the same way as turbine 110. Pressurized fluid may be released from the accumulators 238 so as to pass through the electric generators 240. Electrical energy generated by the generators 240 may be used to power associated downhole equipment (not shown), as illustrated in the flow chart of FIG. 5. This means for storing energy to be used as electrical energy may be employed as an alternative to storing electrical energy in a battery in use of the turbine in certain conditions; for example in high temperature conditions as might be encountered in a wellbore, in which conventional electrical batteries may lose performance or may not function at all.

[0160] The turbine 210 may also be configured to enable hydraulic or pneumatic apparatus directly from pressurized fluid discharged from one or more of the accumulators 238.

[0161] It will appreciated that ancillary apparatus such as pressure control valves, safety valves and the like, which associated with the energy storage arrangements 134, 234 and are mentioned in FIG. 5 have been omitted for clarity from FIGS. 3 and 4. The turbines 10, 110 and 210 may also further comprise a control unit (not shown) with such processing capability as required to regulate the extraction, storage and/or delivery of energy.

[0162] FIG. 6 shows another embodiment of a turbine 310 in accordance with the invention. Features in common with turbine 10 are provided with like reference numerals, incremented by 300. Features in common with turbine 110 are provided with like reference numerals, incremented by 200. Features in common with turbine 210 are provided with like reference numerals, incremented by 100.

[0163] In contrast to turbines 10, 110 and 210 described above, the turbine lacks an electrical stator, and the rotor 314 of the turbine 310 lacks any permanent magnets.

[0164] Instead, energy is transmitted from the rotor 314 via a drive arrangement. The drive arrangement includes an annular rack 342 which is mounted to the rotor 314 and which extends into the mandrel 332 and couples to pinion wheels 344, each of which is mounted to a drive shaft 346. Each drive shaft powers a mechanical accumulator 348, capable of storing mechanical potential energy, e.g. by winding a coil spring or otherwise placing an elastic member into tension or compression.

[0165] The stored mechanical energy may be utilized directly, or (as shown in the figure) the apparatus may be configured for the stored mechanical energy to be released and used to generate electrical energy by powering electrical generators 350 connected in series with the accumulators 348.

[0166] FIG. 7 shows a still further embodiment of a turbine 410 in accordance with the invention. Features in common with the embodiments described above are provided with like reference numerals, incremented by a further 100. Features associated with energy storage and delivery are omitted for clarity.

[0167] The turbine 410 defines a reduced diameter portion 412 of the fluid channel 411. The stator 430, the channel 424, the outer circumferential structure 420 and the bearing 428 are recessed into the mandrel 432, so as to minimize the flow area reduction of the portion 412 of the fluid pathway, in comparison to the adjacent parts of the fluid pathway 411.

[0168] The turbine 410 includes a flow pathway 416 which is separated from the fluid pathway 411, 412, by an internal body portion 454 of the turbine. The leading and trailing faces 456, 457 of the body portion 454 are generally frustoconical, and are provided with a series of inlets 458 to the flow pathway 416, and outlets 459 from the flow pathway.

[0169] In use, a portion of fluid flowing along the fluid channel is captured and channeled through the inlets. This fluid flows along the flow pathway and is returned to the fluid channel (downstream of the portion 412 defined by the turbine 410) through the outlets.

[0170] In alternative embodiments (not shown), the rotor may be supported around, rather than within a bearing (i.e. by the internal body portion) and the rotor may comprise blades which extend outwardly from a circumferential structure, or which extend between inner and outer circumferential structures (through which the flow pathway extends).

[0171] The turbine 410 may optionally be provided with a flow control arrangement to control the flow of fluid into the flow pathway 416 through the inlets (and alternatively or additionally out through the outlets). A flow control arrangement may for example be operated using a control unit, and responsive to sensor signals indicative of a change in fluid conditions.

[0172] FIG. 8 shows a detail view of a part of a still further embodiment of a turbine 510 in accordance with the invention, with features in common with the turbine 410 the same reference numerals, incremented by 100.

[0173] The turbine 510 functions generally as described above, in that an electromotive force is induced in the stators 530, by the magnets 521 (mounted on the rotor 514), when the rotor is urged to rotate under the action of fluid flowing along the flow pathway 516. The turbine is also provided with an annular array of electro magnets 560, mounted in the body 526 of the turbine 510 adjacent to the magnets 521 of the rotor. The electromagnets 560 are operable to alternate polarity as the rotor rotates, so as to maintain opposed polarity to magnets mounted on the rotor as they pass, and thereby provide a magnetic bearing 562 between the rotor and the housing. A magnetic bearing may be less prone to wear or damage than a mechanical bearing or bushing.

[0174] For clarity, details concerning connections between the power supply for the magnetic bearings (which may be charged from power generated by the turbine) is omitted.

[0175] The turbine 510 further includes a Hall sensor control unit 564. In use, Hall sensor signals are received from the stators 530 along electrical connections 566 and 567.

[0176] The values of and the differences in values between the sensor readings from each of the stators corresponds to the relative distance between the rotor 514 and each of the stators, which in turn may correlate to the forces applied along the rotation axis of the rotor by fluid flowing in the fluid pathway. These readings may also correlate to changes in fluid conditions, such as overall flow rate along the fluid channel, viscosity, temperature, etc. Indeed, patterns of Hall sensor readings from the various electrical coils which form the stators 530 may provide additional information about the stability of the rotor's rotation. Instability may be cause for example by debris, damage or a loss of power to the magnetic bearing.

[0177] The turbine 510 also includes a flow control arrangement 570 at the inlet 558 of the flow pathway 516. The flow control arrangement in the embodiment shown is a solenoid valve, but alternate active and passive arrangements will be known to those skilled in the art. The solenoid valve 570 is connected to the Hall sensor control unit 564, which is operable to regulate flow of fluid into the flow pathway by controlling the opening and closing of the valve 570. For example, if the Hall sensor control unit determines that fluid flow is excessive, the valve 570 may be closed to protect the turbine from damage.

[0178] The turbine mandrel may be sized to fall within the drift d of other apparatus, for example on a workstring, as shown in FIG. 9.

[0179] While certain embodiments have been described, these embodiments have been presented by way of example only. Indeed the novel apparatus and methods described herein may be embodied in a variety of other forms; and various omissions, substitutions and changes may be made without departing from the spirit of the invention.