Key information

Title: Device for hydraulically operating a drive wheel of a wellbore tractor, e.g. a motor, and related tractor, wellbore string, and method
Application number: 20180911
Case type: National
Status: 11.11.2024 Patent meddelt (B1)
Filed: 28.06.2018
Effective date: 28.06.2018
Publicly available: 30.12.2019
Next annual fee due: 30.06.2027
Applicant: ALTUS INTERVENTION (TECHNOLOGIES) AS (NO)
Owner: ALTUS INTERVENTION (TECHNOLOGIES) AS (NO)
Inventor: Gerald McInally (NO)
Agent: HÅMSØ PATENTBYRÅ AS (NO)
Granted: 11.11.2024
Patent number: 348290
Expiry date: 28.06.2038

Abstract and drawing

Disclaimer: This text has been machine-scanned and may contain errors – please refer to "Publications" for legally binding content.

A device for hydraulically operating a drive wheel of a wellbore tractor has in certain embodiments at least one cam, and a rotatable assembly arranged to be rotatable with respect to the cam about an axis of rotation. The rotatable assembly has at least one piston. The device also has a chamber and at least one supply port for supplying hydraulic fluid from the chamber to the piston for energizing the piston, the supply port being arranged to be moved between first and second positions relative to the cam. In the first position, the piston can connect to the supply port and be energized to impart force against the cam for producing forward rotation of the assembly. In the second position, the piston can connect to the supply port and be energized to impart force against the cam for producing reverse rotation of the assembly. Embodiments of a related distributor assembly, wellbore tractor, and method are also described.

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Date

Date	Doc. No.	Process	Case number	In/Out	Journal description	To/from
15.11.2024	15-01	Saksbehandling	20180911(348290)	UT	PT Registreringsbrev nasjonal patent (15) (PT20180911)
23.08.2024	14-01	Saksbehandling	20180911	UT	Intention to grant	HÅMSØ PATENTBYRÅ AS
21.08.2024	13-05	Saksbehandling	20180911	INN	P28355NO00_specmarked_210824	HÅMSØ PATENTBYRÅ AS
21.08.2024	13-04	Saksbehandling	20180911	INN	P28355NO00_specclean_210824	HÅMSØ PATENTBYRÅ AS
21.08.2024	13-03	Saksbehandling	20180911	INN	P28355NO00_response_210824	HÅMSØ PATENTBYRÅ AS
21.08.2024	13-02	Saksbehandling	20180911	INN	P28355NO00_claimstranslation_210824	HÅMSØ PATENTBYRÅ AS
21.08.2024	13-01	Saksbehandling	20180911	INN	Korrespondanse (Hovedbrev inn)	HÅMSØ PATENTBYRÅ AS
26.06.2024	12-01	Saksbehandling	20180911	UT	Substantive examination	HÅMSØ PATENTBYRÅ AS
10.03.2023	11-04	Saksbehandling	20180911	INN	P28355NO00 Letter to Patentstyret	HÅMSØ PATENTBYRÅ AS
10.03.2023	11-03	Saksbehandling	20180911	INN	P28355NO00 Amended specification pages 1 to 28	HÅMSØ PATENTBYRÅ AS
10.03.2023	11-02	Saksbehandling	20180911	INN	P28355NO00 Additional sheets, specification mark-up	HÅMSØ PATENTBYRÅ AS
10.03.2023	11-01	Saksbehandling	20180911	INN	Korrespondanse (Hovedbrev inn)	HÅMSØ PATENTBYRÅ AS
10.02.2023	10-01	Saksbehandling	20180911	UT	Substantive examination	HÅMSØ PATENTBYRÅ AS
28.11.2022	09-02	Saksbehandling	20180911	INN	P28355NO00 Letter to Patentstyret 803264_1	HÅMSØ PATENTBYRÅ AS
28.11.2022	09-01	Saksbehandling	20180911	INN	Korrespondanse (Hovedbrev inn)	HÅMSØ PATENTBYRÅ AS
25.01.2021	08-02	Saksbehandling	20180911	INN	P28355NO00 Letter to Patentstyret 803264	HÅMSØ PATENTBYRÅ AS
25.01.2021	08-01	Saksbehandling	20180911	INN	Korrespondanse (Hovedbrev inn)	HÅMSØ PATENTBYRÅ AS
30.04.2020	07-01	Saksbehandling	20180911	UT	PT Varsel om betaling av første årsavgift (3317) (PT20180911)
20.11.2019	06-04	Saksbehandling	20180911	INN	Hovedbrev	HÅMSØ PATENTBYRÅ AS
20.11.2019	06-03	Saksbehandling	20180911	INN	Beskrivelse	HÅMSØ PATENTBYRÅ AS
20.11.2019	06-02	Saksbehandling	20180911	INN	Beskrivelse Additional sheets markup	HÅMSØ PATENTBYRÅ AS
20.11.2019	06-01	Saksbehandling	20180911	INN	Korrespondanse (Hovedbrev inn)	HÅMSØ PATENTBYRÅ AS
30.09.2019	05-02	Saksbehandling	20180911	INN	Hovedbrev	HÅMSØ PATENTBYRÅ AS
30.09.2019	05-01	Saksbehandling	20180911	INN	Korrespondanse (Hovedbrev inn)	HÅMSØ PATENTBYRÅ AS
26.07.2019	04-02	Saksbehandling	20180911	INN	Hovedbrev	HÅMSØ PATENTBYRÅ AS
26.07.2019	04-01	Saksbehandling	20180911	INN	Korrespondanse (Hovedbrev inn)	HÅMSØ PATENTBYRÅ AS
28.01.2019	03-02	Saksbehandling	20180911	UT	PT_report 03:46:43
28.01.2019	03-01	Saksbehandling	20180911	UT	Realitet patent	HÅMSØ PATENTBYRÅ AS
05.07.2018	02-01	Saksbehandling	20180911	UT	Infobrev til oppfinner	HÅMSØ PATENTBYRÅ AS
28.06.2018	01-05	Saksbehandling	20180911	INN	Beskrivelse	HÅMSØ PATENTBYRÅ AS
28.06.2018	01-04	Saksbehandling	20180911	INN	Fullmakt	HÅMSØ PATENTBYRÅ AS
28.06.2018	01-03	Saksbehandling	20180911	INN	Patenttegninger	HÅMSØ PATENTBYRÅ AS
28.06.2018	01-02	Saksbehandling	20180911	INN	Erklæring Søkers rett til oppfinnelse	HÅMSØ PATENTBYRÅ AS
28.06.2018	01-01	Saksbehandling	20180911	INN	Søknadsskjema Patent	HÅMSØ PATENTBYRÅ AS

Description, claims and drawings

Disclaimer: This text has been machine-scanned and may contain errors – please refer to "Publications" for legally binding content.

Description

DEVICE FOR HYDRAULICALLY OPERATING A DRIVE WHEEL OF A WELLBORE TRACTOR, E.G. A MOTOR, AND RELATED TRACTOR, WELLBORE STRING, AND METHOD

Technical field

The present invention relates to the field of tractors for use in wellbores, and in particular to a device for hydraulically operating a drive wheel of a wellbore tractor.

Background

In the oil and gas exploration and production industry, access to wellbores may be facilitated using wellbore tractors. For certain operations, e.g. in intervention operations in a well, a tool string can be conveniently deployed from the surface, lowered through the wellbore, and retrieved back to the surface on a wireline. The wireline is typically spooled out from a vessel or other platform above the top of the wellbore. In order to advance the tool string through the wellbore, in particular in deviated or horizontal sections of the wellbore, a tractor may also be coupled to the wireline. Such a tractor is often termed a “wireline tractor”, and can be used to help to drive the tool string along the wellbore.

Wireline tractors of this kind typically have drive wheels mounted on arms which are extracted from a body of the tractor for urging the drive wheels against a surrounding wall of the wellbore. Pressure against the wall can facilitate wheel traction as the wheels are turned. Variants are known where the tractor has drive wheels on several arms spaced along the body to enhance the overall traction obtained from the tractor. For instance, several drive sections may be included in the tractor, each comprising one or more drive wheels mounted on respective arms.

Some designs for wireline tractors are based on hydraulic operation of the drive wheels, using a hydraulic radial piston motor arranged within the drive wheel. Hydraulic radial piston motors typically include an arrangement of linear pistons which are spaced apart from one another around a centre and which operate to extend or retract in a radial direction from the centre. The pistons may operate in a predetermined sequence to engage a cam ring, thereby generating torque. When embodied in a tractor, the pistons may be mounted on a body which rotates relative to the cam ring as the pistons operate.

The drive wheel can be connected to the rotating body directly or e.g. by planetary gears so that torque is transmitted from the body to the wheel. An example radial piston motor is described in international patent publication number WO92/10677.

In wellbore operations, there may be a need for applying a drive force to move the tool string into the wellbore, e.g. to access far reaches of the wellbore, or out of the wellbore, e.g. to pull out equipment from the wellbore. Current designs incorporating hydraulic piston motors inside the drive wheel of wellbore tractors are generally tuned for utilization of available space, and in small diameter tractors, limited available space for the supply and return of hydraulic fluid can be a constraint on the drive power attainable. Generally, the supply and return paths of hydraulic fluid in existing solutions cannot simply be reversed. Current drive wheel solutions based on radial piston motors can suffer from lack of versatility and/or convenience.

Patent document WO9210677A1 discloses a motor or pump assembly comprising a cylinder block with a plurality of radially positioned cylinder, a piston arranged slidably reciprocable in each of the cylinders, a cam ring cooperating with the pistons and being rotatably journalled on the cylinder block, and a distributor valve arranged centrally in the cylinder block to control a flow of fluid to and from the cylinders in operation. To obtain a relatively large diameter on the rollers and thereby less wear on both the cam ring and the rollers while reducing the outside diameter of the assembly, the rollers are journalled without axial lateral guide at the top end of the pistons, the pistons being guided by the sides in a groove provided in the cam ring. The material of the pistons is moreover removed from both sides as far as the roller so that the piston with a central portion can follow the roller into the groove, whose depth thereby partly overlaps the travel of the piston.

Patent document US2014/0014365A1 discloses a downhole driving unit for insertion into a well, comprising a driving unit housing, a hydraulic motor comprising a hydraulic motor housing, a wheel assembly comprising a stationary part and a rotational part, the stationary part being connected with the driving unit housing and being rotatably connected with a rotational part, the wheel assembly comprising a wheel ring for contacting an inner wall in the well and connected with or forming part of the rotations part. The wheel assembly further comprises the hydraullic motor so that the stationary part and the rotational part constitute the hydraulic motor housing, the hydraulic motor comprising a rotatable section connected with the rotational part for rotating part of the wheel assembly.

Furthermore, the wheel assembly comprises a planetary gearing system comprised in the hydraulic motor housing and the hydraulic motor comprises a rotatable section driving the wheel ring through the planetary gearing system.

Summary of the invention

According to a first aspect of the invention there is provided a device for hydraulically operating a drive wheel of a wellbore tractor, the device comprising: at least one cam; a distributor; a rotatable assembly arranged to be rotatable with respect to the cam and the distributor about an axis of rotation, the assembly comprising at least one piston; the distributor comprising: an inner part; an outer part arranged around the inner part; and a chamber between the inner and outer parts; either the inner part or the outer part of the distributor comprising at least one supply port for supplying hydraulic fluid therethrough from the chamber to the piston for energizing the piston, wherein in a first rotational configuration of said inner or outer part with respect to the other of the inner and outer parts the supply port is arranged in a first position relative to the cam, and in a second rotational configuration of said inner or outer part with respect to the other of the inner and outer parts the supply port is arranged in a second position relative to the cam; wherein, in the first position, the piston can connect to the supply port and be energized to impart force against the cam for producing forward rotation of the assembly, and wherein, in the second position, the piston can connect to the supply port and be energized to impart force against the cam for producing reverse rotation of the assembly.

Changing the rotational position of the part comprising the supply port into the first or second positions can thus advantageously be deployed to change the direction of rotation produced by the device without having to resort to other means. For example, largescale reengineering of the actuation means or hydraulic fluid routes to and from the drive wheel and the tractor wheel arm may be avoidable.

In the first position, the rotatable assembly can obtain communication between the port and the piston in at least one part of its rotation cycle for energizing the piston to impart a force against the cam for generating forward rotation of the assembly.

In the second position, the rotatable assembly can obtain communication between the port and the piston in at least one other part of its rotation cycle for energizing the piston to impart a force against the cam for generating reverse rotation of the assembly about the axis.

The rotatable assembly may typically comprise a plurality of pistons and the outer or the inner part of the distributor may further comprise a plurality of supply ports for supplying hydraulic fluid from the chamber to respective ones of the pistons of the rotatable assembly. The use of multiple pistons can facilitate smooth continuous rotation of the rotatable assembly.

The distributor may be a distributor for distributing hydraulic fluid, e.g. hydraulic oil, between or among the pistons. The supply port may comprise an opening through a wall of the part e.g. a sleeve or a ring.

Either or both of the outer and inner parts may be in the form of a ring or a sleeve. The supply port or ports may be a radial port or ports extending through a wall of the sleeve or ring. The supply port or ports may be spaced apart circumferentially around the sleeve or ring. The chamber may typically comprise an annular chamber between the inner and outer parts.

The device may comprise part of an arm of the tractor. The rotatable assembly may be supported on the arm. The arm or part thereof may be configured to define an annular space for receiving the rotatable assembly or portion thereof in the annular space. The rotatable assembly may have generally an annular shape.

The piston or pistons may be operable to extend linearly, and radially away from the axis of rotation.

The cam may extend circumferentially around the rotatable assembly. The cam may comprise a cam ring. The distributor may comprise a distributor ring or sleeve including the at least one supply port through a material of the ring or sleeve.

The cam ring and the distributor ring or sleeve may typically be arranged concentrically around the axis of rotation. The distributor ring may be arranged disposed at a different position along the axis from the cam ring. The rotational assembly may comprise an annular body portion which may also typically be arranged concentric about the axis. The annular portion may be disposed on an inside or outside of the distributor ring.

The cam may comprise a profile extending circumferentially around the rotatable assembly. The profile may have one or more surface sections forming an acute angle to an axis of linear extension of the piston or pistons of the rotatable assembly. The profile may be a wave profile. The wave profile may comprise crests and troughs. In advantageous embodiments, the rotatable assembly may comprise eight pistons arranged to produce linear extension radially with respect to the axis of rotation. The pistons may be distributed angularly in the assembly about the axis of rotation at substantially equal angular intervals. In embodiments with the eight pistons, the wave profile may advantageously comprise six crests and six troughs. In general, 2, 4, 6, 8, or 10 pistons may be employed. One or more pairs of the pistons, i.e. diametrically opposed in the assembly, may cooperate to be activated simultaneously to impart forces against the cam to produce the rotation in the reverse or forward direction.

In the first position relative to the cam, the at least one piston may be energized with linear extension to impart force against at least one first surface section of the cam. The first surface section may be inclined with respect to the direction of linear extension of the piston for producing the forward rotation. In the second position relative to the cam, the at least one piston may be energized with linear extension to impart force against at least one second surface section of the cam. The second surface section may be inclined with respect to the direction of linear extension of the piston in an opposite sense to the incline of the at least one first surface section, for producing the reverse rotation.

The device may further comprise a coupling for transmitting rotation to the drive wheel in correspondence with the reverse or forward rotation of the rotatable assembly.

The device may be or may comprise a radial piston motor, e.g. a hydraulic radial piston motor.

According to a second aspect of the invention, there is provided a distributor for distributing hydraulic fluid in the device according to the first aspect of the invention, the device comprising at least one cam and a rotatable assembly which is rotatable about an axis of rotation relative to the cam and the distributor, the rotatable assembly comprising at least one piston, the distributor comprising: an inner part; an outer part arranged around the inner part; and a chamber between the inner and outer parts; either the inner part or the outer part of the distributor comprising at least one supply port for transmitting hydraulic fluid therethrough from the chamber to a connected piston of the rotatable assembly for energizing the piston, and being configurable in a first rotational configuration with respect to the other of the inner and outer parts for positioning the supply port in a first position relative to the cam for forward rotation of the rotatable assembly, and in a second rotational configuration with respect to the other of the inner and outer parts for positioning the supply port in a second position relative to the cam for reverse rotation of the rotatable assembly.

The inner or outer part may be movable in relation to the other of the inner and outer parts for locating the port in the first position corresponding to a first surface section of the cam for producing forward rotation of the rotatable assembly, and in the second position corresponding to a second surface section of the cam for producing reverse rotation of the rotatable assembly about the axis.

The outer or the inner part may be lockable to obtain a fixed relationship with respect to the other of the inner and outer parts in either the first or the second position.

The distributor assembly may further comprise a locking device, e.g. releasable locking device, for locking the inner or the outer part in fixed relationship with respect to the other of the inner and outer parts in the first or second position. The locking device may comprise a locking ring and a fastener for fastening the locking ring to either the inner or outer part, so that the locking ring can prevent relative movement between the inner and outer parts when in the first or the second position. The locking device and/or fastener may be releasable to release the inner part from the outer part, or vice versa, to allow movement of the inner part relative to the outer part, or vice versa, between the first and second positions.

In certain embodiments, the outer part may comprise a ring or sleeve around the inner part. The inner part may comprise a boss. The outer part may be slidably disposed around the inner part for slidably rotating the outer part circumferentially around the inner part between the first and second positions. The distributor assembly may further comprise a pair of seals extending around the inner part. The annular chamber may be defined between the seals. The supply ports may comprise an opening through a wall of the outer part for communicating with the chamber. The outer part may be arranged to be releasable from locked configuration with the inner part, e.g. by hand. The outer part may be arranged to be rotatably movable from the first position to the second position relative to the inner part, e.g. by hand.

In other embodiments, the inner part may comprise a ring or sleeve. The outer part may be part of an arm of a tractor. The inner part may be part of an arm of a tractor. The inner part may be slidably disposed within the outer part for slidably rotating the inner part circumferentially within the outer part between the first and second positions. The supply ports may comprise an opening through a wall of the inner part for communicating with the chamber. The inner part may be arranged to be releasable from locked configuration with the outer part, e.g. by hand. The inner part may be arranged to be rotatably movable, e.g. slidably, from the first position to the second position relative to the outer part, e.g. by hand. In these other embodiments also, the distributor assembly may further comprise a pair of seals extending around the inner part. The annular chamber may be defined between the seals.

At least one seal, e.g. the pair of seals, may be disposed between the inner and outer parts. The seal, or either or both of the pair of seals, may be a sliding seal, and/or a ring seal and/or an elastomer seal. The inner or outer part may be arranged to slidably bear against the seal or either or both of the pair of seals. This may allow rotatable circumferential relative movement of the parts between the first and second positions while the seal or seals can continue to function for containing the hydraulic fluid in the chamber, such hydraulic fluid to be distributed to the supply ports.

More generally, either or both of the inner and outer parts may be adapted to be electrically or hydraulically actuable for rotating the inner part relative to the outer part, or vice versa, between the first position and the second position.

The part comprising the ports, e.g. the inner or outer part, may include at least one formation for defining a drain path away for fluid expelled from the piston in part of the rotation cycle of the assembly. The part may comprise formations for draining away return fluid from the pistons that are interspersed between the supply ports around a circumference of the part.

The formation(s) may comprise for instance a groove or recess, e.g. in a surface of the part e.g. in a wall of the part, or a notch, or the like. The groove, recess or notch may provide a flow conduit, gap, passageway or the like, in a region between the rotatable assembly and the part, for draining return fluid from the piston away from the rotatable assembly.

According to a third aspect of the invention, there is provided a wellbore tractor including the device of the first aspect of the invention or the distributor of the second aspect of the invention.

The device may be provided in an extractable arm of the tractor. The tractor may comprise at least one drive wheel and the rotatable assembly of the device may be coupled to the drive wheel to produce forward or reverse rotation of the drive wheel in dependence upon the rotation of the rotatable assembly.

According to a fourth aspect of the invention, there is provided a wellbore string including at least one tractor section, wherein the tractor section includes a drive wheel mounted on an end of an arm which is extractable from a body of the tractor section, the tractor section further including a device according to the first aspect of the invention for operating the drive wheel.

The wellbore string may include a plurality of tractor sections respectively including at least one drive wheel mounted on an end of an arm which may be extractable from a body of the tractor section, wherein at least one of the tractor sections may have a device according to the first aspect of the invention, in which the at least one port may be set in the first position for operating a corresponding drive wheel in a forward direction, and at least one other of the tractor sections may have a device according to the first aspect of the invention in which the at least one port may be set in the second position for operating another corresponding drive wheel in a reverse direction. The wellbore string may typically be configured to be coupled to a wireline. The wellbore string may include at least one well intervention tool. The tractor sections may be tractor drive sections.

According to a fifth aspect of the invention, there is provided a method of operating a tractor in a wellbore, the tractor having at least one section comprising at least one drive wheel mounted on an end of an arm which may be extractable from a body of the section, and the arm including a device according to the first aspect of the invention, the method comprising the steps of: extracting the arm to push the drive wheel against a surrounding wall of the wellbore; supplying hydraulic fluid to the chamber of the device to generate rotation of the tractor wheel in either the forward or reverse direction corre sponding to the position of the ports, the hydraulic fluid supplied to the chamber through the arm.

The method may be a method of configuring and operating the tractor in the wellbore. The method may comprise operating a hydraulic pump to deliver supply the hydraulic fluid to the chamber. The tractor may be included in a wellbore string, and the wellbore string may include the pump in a section of the wellbore string. The pump may be electrically operated. The wellbore tractor may be connected to a wireline. The supply of fluid or electrical power may be supplied to the tractor sections and/or other sections wellbore string through the wireline.

The method may comprise moving the part comprising at least one port between the first position and the second position relative to the cam to switch the direction of rotation of the drive wheel. The method may comprise hydraulically or electrically actuating the part to move it, e.g. using fluid and/or electrical power supplied from the surface.

According to a sixth aspect of the invention, there is provided a method of configuring a wellbore tractor, the tractor having at least one section which comprises at least one device according to the first aspect of the invention or the distributor according to the second aspect of the invention, the method comprising the step of moving the port between the first position and the second position to set the port in either the first position for generating forward motion of the drive wheel or the second position for generating reverse motion of the drive wheel.

The method may further comprise locking the first and second parts to fix them in relative position with one another in either the first or second position. The method may further comprise unlocking first and second parts to allow them to be moved between the first and second positions. The step of moving the parts may comprise rotating the first part relative to the second part by hand. The first part may be fitted around the second part, and the rotating of the first and second parts may be performed, e.g. slidably, while the first part is fitted around the other part, e.g. by hand twisting the one part with respect to the other.

The method may include setting the supply port of at least one section of the tractor in the first position for forward rotation of the drive wheel, and setting the supply port of in at least one other section of the tractor in the second position for reverse rotation of the drive wheel. The method may then include selectively actuating either the section for forward rotation or the other section for reverse rotation. The forward rotation may provide downhole propulsion and the reverse rotation may provide uphole propulsion of the tractor.

Any of the various aspects of the invention may include further features as described in relation to any other aspect, wherever described herein. Features described in one embodiment may be combined in other embodiments. For example, a selected feature from a first embodiment that is compatible with the arrangement in a second embodiment may be employed, e.g. as an additional, alternative or optional feature, e.g. inserted or exchanged for a similar or like feature, in the second embodiment to perform (in the second embodiment) in the same or corresponding manner as it does in the first embodiment.

Various further advantages of the embodiments of the invention and its features are described and will be apparent from the specification throughout.

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

Figure 1 is a cross-sectional representation of a wheel assembly of a wellbore tractor according to a first embodiment of the invention;

Figure 2 is a detail representation of the area A of Figure 1 in close-up;

Figure 3 is a perspective representation highlighting a cam ring and an oil distributor assembly in the wheel assembly of Figure 1 in larger scale;

Figure 4 is a cross-sectional representation of the wheel assembly of Figure 1 with the oil distributor assembly in a first configuration for forward rotation of a rotor of the radial piston motor;

Figure 5 is a cross-sectional representation of part of the wheel assembly in the configuration of Figure 4 but with the rotor omitted;

Figure 6 is a cross-sectional representation of the wheel assembly of Figure 1 with the oil distributor assembly in a second configuration for reverse rotation of the rotor of a radial piston motor;

Figure 7 is a cross-sectional representation of the wheel assembly of Figure 6 with the rotor removed;

Figure 8 is a cross-sectional representation of a wheel assembly of a wellbore tractor including a radial piston motor, according to a second embodiment of the invention;

Figure 9 is a detail representation of the area A of Figure 8 in close-up;

Figure 10 is a perspective representation highlighting a cam ring and an oil distributor assembly in the wheel assembly of Figure 1 in larger scale;

Figure 11 is a cross-sectional representation of the wheel assembly of Figure 8 with the oil distributor assembly in a first configuration for forward rotation of a rotor of the radial piston motor;

Figure 12 is a cross-sectional representation of part of the wheel assembly in the “forward” configuration of Figure 11 but with the rotor omitted;

Figure 13 is a cross-sectional representation of the wheel assembly of Figure 8 with the oil distributor assembly in a second configuration for reverse rotation of the rotor of the radial piston motor;

Figure 14 is a cross-sectional representation of the wheel assembly in the “reverse” configuration of Figure 13 but with the rotor removed;

Figure 15 is a cross-sectional representation of a wheel assembly of a wellbore tractor including a radial piston motor, according to a third embodiment of the invention;

Figure 16 is a detail representation of the area A of Figure 15 in close-up;

Figure 17 is a perspective representation highlighting a cam ring and an oil distributor assembly in the wheel assembly of Figure 15 in larger scale;

Figure 18 is a cross-sectional representation of the wheel assembly of Figure 15 with the oil distributor assembly in a first configuration for forward rotation of a rotor of the radial piston motor;

Figure 19 is a cross-sectional representation of part of the wheel assembly in the “forward” configuration of Figure 18 but with the rotor omitted;

Figure 20 is a cross-sectional representation of the wheel assembly of Figure 15 with the oil distributor assembly in a second configuration for reverse rotation of the rotor of the radial piston motor; and

Figure 21 is a cross-sectional representation of the wheel assembly in the “reverse” configuration of Figure 20 but with the rotor removed.

With reference to Figure 1, a device 1 including a radial piston motor 3 is depicted for hydraulically operating and rotating a drive wheel 4 mounted at an end of a wellbore tractor arm 2.

Near the end of the arm, the arm 2 is configured for supporting working parts of the motor 3, including a rotatable assembly 20. The rotatable assembly 20 is received in an annular cavity 40 in the arm, fitting within the diameter of the wheel 4.

The device 1 includes a cylindrical boss 10 that protrudes from a surface in the arm into an enclosure of the wheel 4. The rotatable assembly 20 has a ring-like configuration and is arranged to fit circumferentially around the boss 10. The assembly 20 is arranged to rotate around the boss 10 about an axis of rotation X that extends through the boss 10. The boss 10 is received in an aperture of the ring-like rotatable assembly 20.

The arm 2 also includes a cam ring 30 extending circumferentially around the rotatable assembly 20. The annular cavity 40 is thus defined in the arm 2 between the cam ring 30 and the boss 10 to accommodate the ring-like rotatable assembly 20.

Furthermore, the device 1 includes a hydraulic oil distributor assembly 12 comprising a distributor sleeve 16 and the boss 10. The hydraulic oil distributor assembly 12 has a distributor sleeve 16 with supply ports 17, as can be seen in more detail with further reference to Figures 2 and 3.

The distributor sleeve 16 (an outer part) is fitted around and is rotatable about the boss 10 (an inner part) for allowing the supply ports 17 to be moved and set in a selected first or second position with respect to the cam ring 30. By rotation of the sleeve 16, high pressure hydraulic supply ports 17 in the sleeve 16 are moved from one position to another relative to the cam ring 30. As will be explained in more detail below, this change in position of the supply ports 17 allows the rotation of the rotatable assembly 20 about the axis X to be switched between forward and reverse directions. This can offer a particularly convenient means of changing the direction of operation of drive wheels in wellbore tractors, which can be advantageous in wellbore operations to apply tractive power in downhole or uphole directions in the wellbore.

The rotatable assembly 20 includes radial pistons 22 which operate to produce extension linearly in a direction radially away from the axis X. In so doing, the pistons 22 can impart a force against the cam ring 30 to generate rotation of the rotatable assembly 20.

It can be noted that the pistons 22 are each coupled to a roller 24 at their far ends. As the rotatable assembly rotates, the rollers 24 follow a profile 31 circumferentially around an inside of the cam ring 30. The rollers 24 are arranged to make touching contact with surfaces 32 of the cam profile 31. When a piston 22 is extended radially toward the cam ring 30, the corresponding roller 24 is urged against a surface section 32 of the cam profile 31. The surface section 32 is angled with respect to the direction of extension generated from the piston 22, causing a torque to be imparted to the rotatable assembly 20 to rotate it. The manner in which this rotation is achieved will be described in further detail below. Reference to Figure 4 may be useful at this point to see more clearly the cam profile 31 and general layout of the device 1.

With reference again to Figure 2 and also Figure 3, detail concerning the boss 10 and the oil distributor assembly 12 can be seen more clearly. The oil distributor assembly 12 functions for distributing hydraulic oil via the supply ports 17 to the pistons 22 for operating the pistons. An annular hydraulic chamber 58 is defined around the boss 10, between the boss 10 and the sleeve 16. Circumferential seals 59a, 59b are arranged between the boss 14 and the sleeve 16. The oil is contained in the chamber 58, facilitated by the seals 59a, 59b to hinder hydraulic oil in the chamber 58 from escaping.

The hydraulic oil is utilized for operating the pistons 22. The oil can be supplied to the pistons 22 as indicated in Figure 2 by arrows S by pumping the oil through a supply conduit 8 into the annular chamber 58. The oil is supplied to the chamber typically via a single supply conduit, e.g. via hydraulic circuitry from a pump. Oil from the annular chamber 58 can then pass through the ports 17 in the distributer sleeve 16 and into a drive chamber 28 of the piston 22.

The pistons 22 are arranged in piston housings 25 in a body 26 of the rotatable assembly 20. Oil is communicated from the port 17 into the drive chamber 28 of the relevant piston 22 through a supply bore 27 in the piston housing 25. The supply bore 27 communicates oil into the drive chamber which can then exert pressure against a surface of the piston to produce linear extension.

The piston 22 is connected so as to be supplied with oil from the port 17 only when an entrance to the supply bore 27 is aligned with the port 17. In general therefore, the rotation of the rotatable body about the axis X, brings the pistons and the entrances to the supply bores 27 into different positions around the circumference sleeve 16, such that the supply bores 27 are brought into and out of alignment with the ports 17 as rotation advances. Thus, communication via the supply bore 27 for supplying the drive chamber 28 with hydraulic oil at high pressure for acting against the piston and driving the rotation of the assembly 20 is achieved only in particular rotational positions of the assembly 20 when the entrances are aligned with the ports 17.

Several supply ports 17 are disposed in the sleeve 16 around its circumference. As the rotatable body 20 rotates therefore, a given piston 22 may align with one and then another port 17 in different rotational positions where the pistons can be supplied with oil from the annular chamber 58 to drive the piston.

In this example, the piston casing 25 includes a separate extract bore 29. The extract bore 29 communicates hydraulic oil which is being expelled from the drive chamber 28 in a return cycle of the piston from the drive chamber 28 out of the assembly and into a flow space defined by a notch 19 in the distributor sleeve 16. The notches 19 for extracting the oil are interspersed between the supply ports 17 circumferentially around the sleeve 16. The extract bore 29 connects to the notch 19 to allow the extraction of the oil from a given piston 22 in particular rotational positions of the assembly 20 where that piston 22 is not connected to a supply port 17 via the supply bore 27.

The extract bore 29 aligns with designated notches 19, see Figure 3, in rotational positions of the assembly where the piston retracts and undergoes the return cycle. The expelled fluid from the drive chamber 28, then passes out of the drive chamber 28, through the extract bore 29 and the opening of the notch 19 between the sleeve 16 and the boss 10. The oil then travels through the notch 19 and onward on a drain path through the enclosure to low pressure hydraulic tank.

An advantage of the second, extract bore 29 communicating with the drive chamber 28 can be that the extract bore 29 can be configured somewhat differently from the supply bore 27, e.g. the supply path may be independent of the drain path. It may also allow the notches 19 to be positioned on the sleeve 16 of the distributor assembly in a favourable location and in specific position for communicating low pressure return oil to the drain path. In this example, the notches 19 for extracting return oil are axially (and of course circumferentially) offset with respect to the supply ports 17. Thus, extracted lowpressure hydraulic fluid is not returned through the same conduits as the high-pressure fluid supplied to the pistons, which can improve design and operability of the motor.

Importantly, the oil distributor assembly 12 is configurable such that the distributor sleeve 16 can be positioned in different rotational positions with respect to the cam profile 31. This means that the ports 17 in the sleeve 16 obtain a corresponding different angular position. Therefore, upon rotation of the rotatable assembly 20 about the boss 10, a given piston 22 will be activated at a different point along the cam profile 31 of the cam 30 (when connected to a supply port 17). In particular, as will be seen below, the sleeve 16 can be positioned in one rotational position so that the pistons 22 operate to generate rotation of the rotatable assembly 20 in a first, forward direction around the boss 10, or in another rotational position so that the pistons 22 operate to generate rotation of the rotatable assembly 20 in second opposite or reverse direction around the boss 10. A locking ring 61 is provided for locking the distributor sleeve 16 with respect to the boss 10 in the selected or desired position. The wheel 4 is coupled to the rotatable assembly 20 through a coupling 5, indicated schematically in dashed outline in Figure 1. The coupling 5 may for instance be a direct coupling or provided via planetary gears. The rotation of the rotatable assembly can thus be transferred to the wheel 4 by way of the coupling 5.

Turning then to refer additionally to Figures 4 to 7, it can be seen how the rotation of the rotatable assembly 20 can be reversed by rotationally repositioning the distributor sleeve 16 with respect to the cam profile 31 and along the rotation path of the assembly 20.

In Figures 4 and 5, a first configuration is shown. The pistons 22 are for the purposes of these figures referenced individually as pistons 22a to 22h. The piston 22a (and corresponding roller 24a) is aligned to engage with a sloping surface section 32a which slopes away clockwise from a crest in the cam profile 31 toward a trough. The piston 22a operates in a pair together with piston 22e which is disposed on the body 20 in 180 degrees opposite orientation to the piston 22a. The pistons 22a, 22e are aligned with the corresponding ports 17 in the distributor sleeve 16 such that both are connected to the annular chamber 58 and receive hydraulic oil at high pressure from the chamber 58 in the drive chambers 28 of the respective pistons 22a, 22e. The pistons 22a, 22e are driven by the fluid in the drive chambers 28 and push against the surface sections 32a, while linearly extending radially away from the sleeve 16. The surface sections 32a that the pistons 22a, 22e engage on the cam profile 31 are arranged at an inclined angle with respect to the direction of linear motion of the pistons 22a, 22e, resulting in an angular force being imparted to the rollers 24 from the surface sections 32a, so that the body 20 is turned clockwise as indicated by arrows R1.

Note that it is only the pistons 22a, 22e that are aligned with respective ports 17 and being driven by the hydraulic fluid from the distributor sleeve 16. In the indicated position of the assembly 20 in its rotational cycle, the other ports 17 of the distributor sleeve 16 are not actively in use in transmitting hydraulic fluid to power the pistons.

Three other sets of 180 degree cooperating pairs of pistons 22 are present on the body 20. The pair of pistons 22c, 22g in Figures 4 and 5 are in the process of retracting as the rotational assembly 20 rotates clockwise. The drive chambers 28 of those pistons 22c, 22g are discharging low pressure fluid through the second, extract bore 29 which is aligned and in communication with the notches 19 in the sleeve 16 to a drain path.

The other two pairs of pistons, namely the pair of pistons 22b, 22f and pair of pistons 22d, 22h are neither connected to the drain path nor the supply path from the hydraulic chamber 58. The pistons 22b, 22f are positioned so that respective rollers 24 are fully extended and located in a trough of the cam profile 31 having undergone an earlier drive cycle. Upon further rotation of the rotational assembly 20 about the boss 10 and distributor sleeve 16) the rollers 24 will travel on the slope from the trough to the next crest in the cam profile 31, causing discharge of low pressure oil from the drive chambers 28 to the drain path.

Conversely, the pistons 22d, 22h are positioned so that respective rollers 24 are fully retracted and located on a crest of the cam profile 31 having completed an earlier discharge cycle. Upon further rotation of the rotational assembly 20 about the boss 10 (and sleeve 16) the rollers 24 will travel on the slope from the crest to the next trough in the cam profile 31, with high pressure fluid being supplied on a supply path from the port 17 in the sleeve 16 to the drive chambers 28 for driving the extension of the pistons 22d, 22h and rotation of the rotatable assembly 20.

In this manner, the various piston pairs operate in sequence to extend and retract in an alternating pattern as the body 20 rotates, as and when through rotation the necessary alignment with ports/notches in distributor sleeve 16 is obtained. The extraction phase of the pistons drives rotation against the cam under high pressure, while due to the mechanical interaction with the profile of the cam as it rotates, the surface sections of the cam profile 31 force the pistons subsequently to retract against low pressure. The opera tion in pairs can double the power available as opposed to other variants for instance using just one piston actively to drive rotation at any one time.

In Figures 6 and 7, the general operation of the rotatable assembly 20 is the same as above, except the direction of its rotation is reversed. The rotatable assembly 20 is rotatable in the direction indicated by arrows R2. Sequential extension and retraction of pistons takes place in the same way as the body 20 rotates, with the rollers 24 following the cam profile 31 circumferentially around the inside of the cam ring 30. The important and only difference in configuration to note here, however, is that the distributor sleeve 16 is positioned in a different orientation with respect to the cam profile 31. As can be seen in Figure 7, the cam ring 31 and distributor sleeve 16 are arranged concentrically, and the sleeve 16 has been rotated with respect to the cam profile 31, and the boss 10, by an angle α of 30 degrees.

Thus, the ports 17 for supplying high pressure hydraulic oil from the annular chamber 58 connect with pistons 22 when the pistons are positioned to engage surfaces 32b of the cam profile 31 that slope away from a crest toward a trough anti-clockwise from the crest, producing torque and movement of the rotatable assembly 20 in a direction indicated with arrows R2 which is opposite to the direction R1 of Figures 4 and 5.

More specifically, in the rotational position of the assembly 20 in Figure 6, the piston 22c (and corresponding roller 24c) is aligned to engage with a sloping surface section 32b which slopes away from a crest in the cam profile 31 toward a trough in an anticlockwise direction. The piston 22c operates in a pair together with piston 22g which is disposed in the assembly 20 in 180 degrees opposite orientation to the piston 22c. In this case, the pistons 22c, 22g are aligned with ports 17 in the distributor sleeve 16 such that they are both connected to the annular chamber 58 and receive hydraulic oil at high pressure from the chamber 58 in the drive chambers 28 of the respective pistons 22c, 22g. The pistons 22c, 22g are driven by the oil in the drive chambers 28 and push against the surface sections 32b, while linearly extending radially away from the sleeve 16. The surface sections 32b that the pistons 22c, 22g engage with on the cam profile 31 are arranged at an inclined angle with respect to the direction of linear motion of the pistons 22c, 22g resulting in an angular force being imparted to their respective rollers 24 from the surface sections 32b, so that the body 20 is turned anti-clockwise as indicated by arrows R2.

With regard to the other pairs of pistons, it can be seen that pistons 22a, 22e are discharging while connected to the drain path via bore 29 and notch openings 19. The others are neither discharging nor being driven, and are not aligned with either the notch openings 19 or the ports 17. More specifically, the pair of pistons 22b, 22f are fully retracted awaiting next a drive phase which will commence when the supply bore 27 aligns with the next supply port 17 upon further rotation of the assembly 20. The pair of pistons 22d, 22h are fully extended awaiting next a discharge phase which will commence when the supply bores 27 of the pistons 22d, 22h align with the next supply port 17 in the distributor sleeve 16 along its circumference.

Providing the distributor assembly 12 where the distribution sleeve 16, and its associated ports 17, is readily positioned in different rotational orientations and rotated relative to the cam profile 31 for obtaining the reverse direction can be advantageous. In particular, the direction of rotation of a tractor drive wheel coupled to the assembly, can be switched without requiring more extensive reconfiguration, and the supporting hydraulic circuitry for supplying hydraulic oil to the distributor assembly can effectively be the same for both directions of rotation while minimizing need for bi-directional hydraulic circuitry. In designs for tractor wheel motors such as illustrated, open space within the enclosure of the wheel 4 is used for containing low pressure hydraulic fluid being returned from the pistons on the drain path during their discharge, and the present solution can helpfully allow this design feature to be maintained.

Practically, in order to position and set the distributor sleeve 16 in different orientations, the sleeve 16 can be released from the boss 10 and rotated relative to the boss 10 to place the ports 17 in the necessary rotated position, in this case 30 degrees circumferentially about the boss 10 from the earlier position. When in the desired position, the sleeve 16 is locked relative to the boss 10 by a locking plate which is fastened in place by a releasable fastener, in this case a tightening screw, to the boss 10. The motor can then be operated as described above, obtaining rotation of the assembly 20 in the forward direction. In order to move the ports 17 to the other position, the tightening screw is undone and the locking plate 61 for locking the sleeve 16 with respect to the boss 10 is released to allow the sleeve 16 to be rotated to the new position. The sleeve 16 can be rotated to the new position by hand, for example by sliding and turning it by hand about the boss 10 while the circumferential seals in the distributor assembly 12 remain in place. Before rotating the sleeve 16, the rotatable assembly 20 is typically removed from the motor cavity 40. The seals may be elastomer ring seals or similar. The sleeve 16 could also be lifted off the boss 10 and then replaced back on the boss 10 in the rotated position. No adhesive or the like is used or required between the distributor sleeve 16 and the boss 10.

The process of positioning the sleeve 16 above exemplifies a manual “pre-set” process which may be employed in the course of assembly or pre-configuration of a tractor section before deployment in a wellbore. Thus, wellbore tractor sections, e.g. drive sections, can be configured before deployment in a wellbore by setting the ports 17 in either the first position or second position for forward or reverse rotation of the rotatable assembly 20. By the manual pre-setting of the sleeve prior to deployment, the tractor can incorporate drive sections that are dedicated to uphole or downhole propulsion during the subsequent deployment and operation in the well.

In some operations, one or more tractor sections may have the sleeve 16 set in the position for forward rotation to facilitate movement of the tractor downhole and one or more tractor sections may have the sleeve 16 set in the other position for reverse rotation to facilitate movement of the tractor uphole, as may be useful e.g. to help to dislodge equipment or pull equipment out of the wellbore, e.g. in well intervention. As such, forward and reverse tractor sections can easily be configured and can be deployed in the same run in a wellbore. In such embodiments however, the sections for movement downhole and the sections for movement uphole would not both be operational at the same time. The tractor is therefore arranged to be able to select and operate separately either the “uphole” or the “downhole” sections. Different drive sections of a tractor can be selectively activated and deactivated through the hydraulic system in the tractor. In the present example, such a hydraulic system can be employed to operate the motor 3 of a first drive section with ports 17 in the distributor assembly 12 positioned for downhole movement and operate another motor 3 of a second drive section with ports 17 in the distributor assembly 12 set for uphole movement. By using a bypass line and arranging a valve module between the first and second drive sections, a supply of hydraulic fluid from a distribution point in the valve module to the hydraulic motor of either the first or the second drive sections can be switched on or off, so that the motor of the first drive section can be used for movement downhole while the second drive section is inoperative, and vice versa. The hydraulic system in the tractor supplies the chamber in the distributor assembly 12 -with high pressure hydraulic fluid for operating the wheel 4. In other variants, the position of the ports 17 can be changed from the first to the second position when the tractor is deployed in the well. In such variants, the distributor assembly 12 can be implemented where the distributor sleeve is coupled to the boss 10 so that it can be rotated to different positions with respect to the boss 10 (and the cam profile 31) by remote actuation, e.g. hydraulically or by electric control. This can allow switching of the distributor sleeve 16 between different rotational orientations while the tractor is deployed in a wellbore. This can avoid the need for pre-configuring the distributor assembly 12 with the sleeve 16 in one or the other position. For example, the distributor sleeve 16 may in such an embodiment have a surface to which hydraulic oil may be supplied and against which it may apply pressure to produce a component of torque to turn the distributor sleeve 16 from the first position relative to the cam to the second position. Hydraulic oil may be routed to such a member by switching a valve in the hydraulic circuit to direct fluid through a conduit to a chamber which is in communication with the surface. In such variants also, by way of changing the position of the ports when in the well, it can be appreciated that the same drive sections as previously used for downhole propulsion (in the same trip) can be used for uphole propulsion. For example, after the drive sections have been engaged in downhole propulsion in the well, the distributor sleeves 16 in those drive sections are moved and set in their second positions while the tractor remains in the well, e.g. by hydraulic or electric actuation, to reverse their directions of rotation. The drive sections are thereafter operated to provide uphole propulsion of the tractor. Since the drive sections can be used for downhole and then, once ports are switched, uphole propulsion, the total number of drive sections needed in the tractor may be reduced. All sections can be active in both uphole and downhole propulsion phases, and inclusion of redundant passive sections can be avoided. In turn, this can allow savings to be made in the overall length of the tractor.

While the above described example utilizes eight pistons and a cam profile 31 that is wave shaped with six crests or troughs, it will be appreciated that in other embodiments the rotational assembly 20 can have fewer or a greater number of pistons 22, and the cam profile 31 can have other numbers of troughs and crests or other arrangement of inclined slopes to generate a torque on the rotatable assembly 20.

In Figures 8 to 14 another example of a device 101 is depicted having corresponding components to those of the embodiment of Figures 1 to 7. The corresponding components are referenced with the same numerals but incremented by one hundred, and the description of these are not repeated here.

The distributor assembly 112 is configured differently in this example, and instead of separate supply and extract bores 27, 29, a bi-directional in/out bore 187 is provided. The in/out bore 187 serves for communication of oil into the drive chamber 128, and, in the return phase, out of the drive chamber 128. Thus, when the piston retracts, oil is expelled from the drive chamber 128 to the drain path through the bore 187. Conversely, when the piston is being energized and extends, oil is supplied into the drive chamber 128 for energizing the piston, and the oil passes through the same bore 187.

However, the return oil does not pass into the annular chamber 158 that contains high pressure oil. Rather, it is conveyed in grooves 189 extending axially on the sleeve 116 at positions between adjacent supply ports 117. The returning oil is carried along the groove between the sleeve 116 and a body of the rotatable assembly onward on the drain path to low pressure hydraulic tank. The bore 187 communicates with the grooves 189 in the same positions as the notches 19 in the embodiment of Figures 1 to 7.

In Figures 15 to 21, another example of a device 201 is depicted having corresponding components to those of the embodiment of Figures 1 to 7. The corresponding components are referenced with the same numerals but incremented by two hundred, and the description of these are not repeated here.

The general operation of the device is similar to that of the embodiments described above, although the rotatable assembly 220 in this example has an annular body portion which fits inside the distributor ring 286 of the distributor assembly 212. The boss 210 in this example does not form part of the distributor assembly 212. Like the embodiments of Figures 1 to 14 above however, both the distributor ring 286 and the cam ring 230 are concentrically arranged around the axis of rotation X of the rotatable assembly 220.

In this example, oil is supplied from the ports 217 inwardly toward the centre of the distributor ring 286. An in/out bore 227 in the piston housing is connected to the ports 217 through a conduit in the annular body portion of the assembly 220 for supplying high pressure hydraulic oil to the drive chambers 228 of the pistons when they are energized. The in/out bore 227 is bi-directional such that return fluid to be expelled from the drive chamber in the retraction cycle also passes through the in/out bore 227 and the conduit in the annular body portion. However, in the rotational position at which the retraction of the piston 222 takes place (due to interaction with the cam profile 231), the bore 227 is in communication with axial recesses 219 in an inside face of the distributor ring 286. The return oil can then pass along the recesses on the drain path to hydraulic low-pressure tank.

It can be appreciated that the distributor ring 286 and piston housings 225 can be embodied in other ways. For example, the piston housings 225 may have unidirectional supply and extract bores for bringing hydraulic oil in and out of the drive chamber 228. The distributor ring 286 may be adapted accordingly with notches, ports or other formations for allowing the hydraulic oil to exit from the assembly 220 and be conveyed in a micro space between the distributor ring 286 and the annular body of the rotational assembly 220 on the drain path.

The hydraulic distributor assembly 212 has in this example an outer part in the form of a circumferential wall 284 of the arm 202, and an inner part in the form of the distributor ring 286. The annular chamber 258 is defined between the wall 284 and the distributor ring 286, extending around an outside of the distributor ring 286. Annular seals 259a, 259b are provided for delimiting the chamber 258 to the annular region formed therebetween. The chamber 258 is supplied with high pressure hydraulic oil through a supply conduit 208 in the arm 202. As in the embodiments of Figures 1 to 14 above, the distributor ring 286 is rotatable about the axis X to place the ports 217 in different positions circumferentially relative to the cam ring 230, so as to provide forward, clockwise rotation of the rotatable assembly 220 in one position and reverse, anti-clockwise rotation in another position. The distributor ring 286 is fixed to the arm 202 in the selected position, for either reverse or forward rotation, by screws. In configuring the motor 203 for operation, the screws 295 are removed to release the distributor ring 286 and the distributor ring 286 is rotated to the other position where it is again fixed to the body 205 by the screws 295. The rotatable assembly is put in place, so as to be rotatable about the boss 210, and the device otherwise prepared for operation. Hydraulic oil is supplied to the chamber 258 for driving rotation for operating the motor 203.

For performing operations in a wellbore such as a well intervention, a tool string coupled to a wireline is prepared and includes multiple tractor sections each carrying a motor 3, 103, 203 for driving a wheel on an extractable end of an arm 2, 102, 202. In at least one of the tractor sections, i.e. drive sections, the oil distributor assembly 12, 112, 212 has the high-pressure supply ports 17, 117, 217 set in a first position relative to the cam profile that can produce rotation in a forward direction. In at least one other tractor section, the oil distributor assembly 12, 112, 212 has the high-pressure supply ports 17, 117, 217 set in a second position relative to the cam profile that can produce rotation in a forward direction. The forward rotation section(s) may be separately selected for driving the tractor downhole, and the reverse rotation section(s) may be selected for driving the tractor uphole.

Various modifications and improvements may be made without departing from the scope of the invention herein described.

Claims

CLAIMS

1. A device (1, 101, 201) for hydraulically operating a drive wheel of a wellbore tractor, the device comprising:

at least one cam (30, 130, 230);

a distributor (12, 112, 212); and

a rotatable assembly (20, 120, 220) arranged to be rotatable with respect to the cam and the distributor about an axis of rotation (X), the assembly comprising at least one piston (22, 122, 222); and

characterized in that

the distributor comprises:

an inner part (10, 110, 286);

an outer part (16, 116, 284) arranged around the inner part; and

a chamber (58, 158, 258) between the inner and outer parts;

either the inner part or the outer part of the distributor comprising at least one supply port (17, 117, 217) for supplying hydraulic fluid therethrough from the chamber to the piston for energizing the piston, wherein

in a first rotational configuration of said inner or outer part with respect to the other of the inner and outer parts the supply port is arranged in a first position relative to the cam, and

in a second rotational configuration of said inner or outer part with respect to the other of the inner and outer parts the supply port is arranged in a second position relative to the cam;

wherein, in the first position, the piston can connect to the supply port and be energized to impart force against the cam for producing forward rotation of the assembly, and

wherein, in the second position, the piston can connect to the supply port and be energized to impart force against the cam for producing reverse rotation of the assembly.

2. A device as claimed in claim 1, further comprising a coupling (5) for transmitting rotation to the drive wheel in correspondence with the reverse or forward rotation of the rotatable assembly, the coupling being provided via planetary gears.

3. A device as claimed in claim 1 or 2, wherein the rotatable assembly comprises a plurality of pistons (22, 122, 222) and the outer or the inner part of the distributor com prises a plurality of supply ports (17, 117, 217) for supplying hydraulic fluid from the chamber to the pistons of the rotatable assembly.

4. A device as claimed in any preceding claim, wherein either or both of the outer and inner parts of the distributor are in the form of a ring or a sleeve.

5. A device as claimed in claim 4, wherein the supply ports are radial ports extending through a wall of the sleeve or ring.

6. A device as claimed in claim 4 or 5, wherein the supply ports are spaced apart circumferentially around the sleeve or ring.

7. A device as claimed in any preceding claim, wherein the chamber comprises an annular chamber (58, 158, 258).

8. A device as claimed in any preceding claim, wherein the piston is operable to extend linearly and radially away from the axis of rotation.

9. A device as claimed in any preceding claim, wherein the rotatable assembly is supported on a supporting structure (2, 102, 202).

10. A device as claimed in claim 9, wherein the supporting structure of the device comprises an annular space (40, 140, 240) for receiving the rotatable assembly.

11. A device as claimed in claim 10, wherein the rotatable assembly has a generally annular shape.

12. A device as claimed in any preceding claim, wherein the cam comprises a wave profile (31, 231) extending circumferentially around the rotatable assembly.

13. A device as claimed in claim 12, wherein the wave profile comprises six crests and six troughs.

14. A device as claimed in any preceding claim, wherein in the first position, the at least one piston is energized with linear extension to impart force against at least one first surface section (32a, 132a, 232a) of the cam which is inclined with respect to the direction of linear extension of the piston for producing the forward rotation.

15. A device as claimed in claim 14, wherein in the second position, the at least one piston is energized with linear extension to impart force against at least one second surface section (32b, 132b, 232b) of the cam which is inclined with respect to the direction of linear extension of the piston in an opposite sense to the incline of the at least one first surface section, for producing the reverse rotation.

16. A device as claimed any preceding claim, being a hydraulic radial piston motor.

17. A device as claimed in any preceding claim, further comprising a formation about which the assembly is rotatable.

18. A device as claimed in claim 17, wherein the formation comprises the distributor.

19. A device as claimed in any preceding claim, wherein the axis of rotation (X) extends through the assembly.

20. A distributor (12, 112, 212) for distributing hydraulic fluid in the device according to any preceding claim, the device comprising at least one cam (30, 130, 230) and a rotatable assembly (20, 120, 220) which is rotatable about an axis of rotation relative to the cam and the distributor, the rotatable assembly comprising at least one piston (22, 122, 222), the distributor comprising:

an inner part (10, 110, 286);

an outer part (16, 116, 284) arranged around the inner part; and

a chamber (58, 158, 258) between the inner and outer parts;

either the inner part or the outer part of the distributor comprising at least one supply port (17, 117, 217) for transmitting hydraulic fluid therethrough from the chamber to a connected piston of the rotatable assembly for energizing the piston, and being configurable in a first rotational configuration with respect to the other of the inner and outer parts for positioning the supply port in a first position relative to the cam for forward rotation of the rotatable assembly, and in a second rotational configuration with respect to the other of the inner and outer parts for positioning the supply port in a second position relative to the cam for reverse rotation of the rotatable assembly.

21. A distributor as claimed in claim 20, wherein the outer part is lockable to obtain a fixed relationship with respect to the inner part in either the first or the second position.

22. A distributor as claimed in claim 21, which further comprises a locking device (61, 161) for locking the inner part in fixed relationship with respect to the outer part in the first or second position.

23. A distributor as claimed in claim 22, wherein the locking device comprises a locking ring (61, 161) and a fastener for fastening the locking ring to either the inner or outer part, so that the locking ring prevents relative movement between the inner and outer parts.

24. A distributor as claimed in any of claims 20 to 23, wherein the outer part comprises a ring or sleeve (16, 116) around the inner part.

25. A distributor as claimed in any of claims 20 to 24 wherein the outer part is slidably disposed around the inner part for slidably rotating the outer part circumferentially around the inner part between the first and second positions.

26. A distributor as claimed in any of claims 20 to 25, further comprising a pair of seals (59a, 59b; 159a, 159b; 259a, 259b) extending around the inner part, the annular chamber being defined between the seals, the supply ports comprising an opening through a wall of the outer part for communicating with the chamber.

27. A distributor as claimed in any of claims 20 to 26, wherein the outer part is arranged to be releasable from locked configuration with the inner part by hand.

28. A distributor as claimed in any of claims 20 to 27, wherein the outer part is arranged to be rotatably movable from the first position to the second position relative to the inner part by hand.

29. A distributor as claimed in any of claims 20 to 28, wherein either or both of the inner and outer parts are adapted to be electrically or hydraulically actuable for rotating the inner part relative to the outer part between the first position and the second position.

30. A distributor as claimed in any of claims 20 to 29, wherein the one part that comprises the ports includes at least one formation (19) for defining a drain path away for fluid expelled from the piston in part of the rotation cycle of the assembly.

31. A distributor as claimed in claimed in the claim 30, wherein the formation comprises a groove or notch (19) for providing a flow conduit for draining fluid between the assembly and the part.

32. A wellbore tractor including the device (1, 101, 201) of any of claims 1 to 19 or the distributor (12, 112, 212) of any of claims 20 to 31.

33. A wellbore tractor as claimed in claim 32, wherein the device is provided in an extractable arm (2, 102, 202) of the tractor.

34. A wellbore tractor as claimed in claim 32 or 33, wherein the tractor comprises at least one drive wheel (4, 104, 204) and the rotatable assembly (20, 120, 220) of the device is coupled to the drive wheel to produce forward or reverse rotation of the drive wheel in dependence upon the rotation of the rotatable assembly.

35. A wellbore string including at least one tractor section, wherein the tractor section includes a drive wheel (4, 104, 204) mounted on an end of an arm (2, 102, 202) which is extractable from a body of the tractor section, the tractor section further including a device (1, 101, 201) as claimed in any of claims 1 to 19 for operating the drive wheel.

36. A wellbore string as claimed in claim 35, including a plurality of tractor sections respectively including at least one drive wheel mounted on an end of an arm (2, 102, 202) which is extractable from a body of the tractor section, wherein at least one of the tractor sections has a device (1, 101, 201) as claimed in any of claims 1 to 19 in which the at least one port (17, 117, 217) is set in the first position for operating a corresponding drive wheel in a forward direction, and at least one other of the tractor sections has a device (1, 101, 201) as claimed in any of claims 1 to 19 in which the at least one port (17, 117, 217) is set in the second position for operating another corresponding drive wheel in a reverse direction.

37. A wellbore string as claimed in claim 35 or 36 which is configured to be coupled to a wireline.

38. A wellbore string as claimed in claim 36 or 37 including at least one well intervention tool.

39. A method of operating a tractor in a wellbore, the tractor having at least one section comprising at least one drive wheel (4, 104, 204) mounted on an end of an arm (2, 102, 202) which may be extractable from a body of the section, and the arm including a device (1, 101, 201) according to any of claims 1 to 19, the method comprising the steps of:

extracting the arm to push the drive wheel against a surrounding wall of the wellbore;

supplying hydraulic fluid to the chamber (58, 158, 258) of the device to generate rotation of the tractor wheel in either the forward or reverse direction corresponding to the position of the port or ports (17, 117, 217), the hydraulic fluid supplied to the chamber through the arm.

40. A method of configuring a wellbore tractor, the tractor having at least one section which comprises at least one device (1, 101, 201) according to any of claims 1 to 19 or the distributor (12, 112, 212) according to any of claims 20 to 31, the method comprising the step of moving the port (17, 117, 217) between the first position and the second position to set the port in either the first position for generating forward motion of the drive wheel (4, 104, 204) or the second position for generating reverse motion of the drive wheel.

Patentkrav

1. Anordning (1, 101, 201) for hydraulisk betjening av et drivhjul på en brønntraktor, idet anordningen omfatter:

minst én kam (30, 130, 230);

en fordeler (12, 112, 212); og

en roterbar sammenstilling (20, 120, 220) anordnet til å være roterbar med hensyn til kammen og fordeleren om en rotasjonsakse (X), idet sammenstillingen omfatter minst ett stempel (22, 122, 222); og

k a r a k t e r i s e r t v e d at

fordeleren omfatter:

en innerdel (10, 110, 286);

en ytterdel (16, 116, 284) anordnet om innerdelen; og

et kammer (58, 158, 258) mellom inner- og ytterdelene;

enten innerdelen eller ytterdelen av fordeleren omfatter minst én tilførselsport (17, 117, 217) for å tilføre hydraulikkfluid derigjennom fra kammeret til stempelet for å energisere stempelet, hvor

i en første rotasjonskonfigurasjon av nevnte inner- eller ytterdel med hensyn til den andre av inner- og ytterdelene er tilførselsporten anordnet i en første posisjon i forhold til kammen, og

i en andre rotasjonskonfigurasjon av nevnte inner- eller ytterdel med hensyn til den andre av inner- og ytterdelene er tilførselsporten anordnet i en andre posisjon i forhold til kammen;

hvor, i den første posisjonen, stempelet kan kobles til tilførselsporten og bli energisert for å overføre kraft mot kammen for å frembringe fremoverrotasjon av sammenstillingen, og

hvor, i den andre posisjonen, stempelet kan kobles til tilførselsporten og bli energisert for å overføre kraft mot kammen for å frembringe bakoverrotasjon av sammenstillingen.

2. Anordning ifølge krav 1, videre omfattende en kobling (5) for å overføre rotasjon til drivhjulet i overensstemmelse med bakover- eller fremoverrotasjonen av den roterbare sammenstillingen, idet koblingen er tilveiebrakt via planetgir.

3. Anordning ifølge krav 1 eller 2, hvor den roterbare sammenstillingen omfatter en flerhet av stempler (22, 122, 222) og ytter- eller innerdelen av fordeleren omfatter en flerhet av tilførselsporter (17, 117, 217) for å tilføre hydraulikkfluid fra kammeret til stemplene til den roterbare sammenstillingen.

4. Anordning ifølge et hvilket som helst av de foregående kravene, hvor den ene eller begge av ytter- og innerdelene av fordeleren er i form av en ring eller en hylse.

5. Anordning ifølge krav 4, hvor tilførselsportene er radielle porter som strekker seg gjennom en vegg i hylsen eller ringen.

6. Anordning ifølge krav 4 eller 5, hvor tilførselsportene er plassert med avstand fra hverandre periferisk om hylsen eller ringen.

7. Anordning ifølge et hvilket som helst av de foregående kravene, hvor kammeret omfatter et ringformet kammer (58, 158, 258).

8. Anordning ifølge et hvilket som helst av kravene, hvor stempelet kan betjenes for å strekke seg lineært og radielt bort fra rotasjonsaksen.

9. Anordning ifølge et hvilket som helst av de foregående kravene, hvor den roterbare sammenstillingen støttes på en støttestruktur (2, 102, 202).

10. Anordning ifølge krav 9, hvor støttestrukturen til anordningen omfatter et ringrom (40, 140, 240) for å romme den roterbare sammenstillingen.

11. Anordning ifølge krav 10, hvor den roterbare sammenstillingen er generelt ringformet.

12. Anordning ifølge et hvilket som helst av de foregående kravene, hvor kammen omfatter en bølgeprofil (31, 231) som strekker seg periferisk om den roterbare sammenstillingen.

13. Anordning ifølge krav 12, hvor bølgeprofilen omfatter seks topper og seks daler.

14. Anordning ifølge et hvilket som helst av de foregående kravene, hvor i den første posisjonen er det minst ene stempelet energisert med lineær ekstensjon for å overføre kraft mot minst én første overflateseksjon (32a, 132a, 232a) på kammen som er vinklet med hensyn til retningen av lineær ekstensjon av stempelet for å frembringe fremoverrotasjonen.

15. Anordning ifølge krav 14, hvor i den andre posisjonen er det minst ene stempelet energisert med lineær ekstensjon for å overføre kraft mot minst én andre overflateseksjon (32b, 132b, 232b) på kammen som er vinklet med hensyn til retningen av lineær ekstensjon av stempelet i en motsatt forstand av vinklingen til den minst ene første overflateseksjonen for å frembringe bakoverrotasjonen.

16. Anordning ifølge et hvilket som helst av de foregående kravene, idet den er en hydraulisk radialstempelmotor.

17. Anordning ifølge et hvilket som helst av de foregående kravene, videre omfattende en formasjon om hvilken sammenstillingen er roterbar.

18. Anordning ifølge krav 17, hvor formasjonen omfatter fordeleren.

19. Anordning ifølge et hvilket som helst av de foregående kravene, hvor rotasjonsaksen (X) strekker seg gjennom sammenstillingen.

20. Fordeler (12, 112, 212) for fordeling av hydraulikkfluid i anordningen ifølge et hvilket som helst av de foregående kravene, idet anordningen omfatter minst én kam (30, 130, 230) og en roterbar sammenstilling (20, 120, 220) som er roterbar om en rotasjonsakse i forhold til kammen og fordeleren, idet den roterbare sammenstillingen omfatter minst ett stempel (22, 122, 222), idet fordeleren omfatter:

en innerdel (10, 110, 286);

en ytterdel (16, 116, 284) anordnet om innerdelen; og

et kammer (58, 158, 258) mellom inner- og ytterdelene;

idet enten innerdelen eller ytterdelen av fordeleren omfatter minst én tilførselsport (17, 117, 217) for å overføre hydraulikkfluid derigjennom fra kammeret til et tilkoblet stempel av den roterbare sammenstillingen for å energisere stempelet, og kan konfigureres i en første rotasjonskonfigurasjon med hensyn til den andre av inner- og ytterdelene for å posisjonere tilførselsporten i en første posisjon i forhold til kammen for fremoverrotasjon av den roterbare sammenstillingen, og i en andre rotasjonskonfigurasjon med hensyn til den andre av inner- og ytterdelene for å posisjonere tilførselsporten i en andre posisjon i forhold til kammen for bakoverrotasjon av den roterbare sammenstillingen.

21. Fordeler ifølge krav 20, hvor ytterdelen er låsbar for å oppnå et fast forhold med hensyn til innerdelen i enten den første eller den andre posisjonen.

22. Fordeler ifølge krav 21, som videre omfatter en låseanordning (61, 161) for å låse innerdelen i fast forhold med hensyn til ytterdelen i den første eller andre posisjonen.

23. Fordeler ifølge krav 22, hvor låseanordningen omfatter en låsering (61, 161) og en festeanordning for å feste låseringen til enten inner- eller ytterdelen, slik at låseringen forhindrer relativ bevegelse mellom inner- og ytterdelene.

24. Fordeler ifølge et hvilket som helst av kravene 20 til 23, hvor ytterdelen omfatter en ring eller hylse (16, 116) om innerdelen.

25. Fordeler ifølge et hvilket som helst av kravene 20 til 24, hvor ytterdelen er glidbart anordnet om innerdelen for å glidbart rotere ytterdelen periferisk om innerdelen mellom de første og andre posisjonene.

26. Fordeler ifølge et hvilket som helst av kravene 20 til 25, videre omfattende et par med pakninger (59a, 59b; 159a, 159b; 259a, 259b) som strekker seg om innerdelen, idet det ringformede kammeret er definert mellom pakningene, idet tilførselsportene omfatter en åpning gjennom en vegg av ytterdelen for kommunikasjon med kammeret.

27. Fordeler ifølge et hvilket som helst av kravene 20 til 26, hvor ytterdelen er anordnet til å være løsgjørbar fra låst konfigurasjon med innerdelen for hånd.

28. Fordeler ifølge et hvilket som helst av kravene 20 til 27, hvor ytterdelen er anordnet til å være roterbart bevegelig fra den første posisjonen til den andre posisjonen i forhold til innerdelen for hånd.

29. Fordeler ifølge et hvilket som helst av kravene 20 til 28, hvor den ene eller begge av inner- og ytterdelene er tilpasset til å være elektrisk eller hydraulisk aktuerbare for å rotere innerdelen i forhold til ytterdelen mellom den første posisjonen og den andre posisjonen.

30. Fordeler ifølge et hvilket som helst av kravene 20 til 29, hvor den ene delen som omfatter portene, inkluderer minst én formasjon (19) for å definere en dreneringsbane bort for fluid som drives ut av stempelet i en del av rotasjonssyklusen til sammenstillingen.

31. Fordeler ifølge krav 30, hvor formasjonen omfatter et spor eller et hakk (19) for å tilveiebringe en strømningskanal for drenering av fluid mellom sammenstillingen og delen.

32. Brønntraktor inkludert anordningen (1, 101, 201) ifølge et hvilket som helst av kravene 1 til 19 eller fordeleren (12, 112, 212) ifølge et hvilket som helst av kravene 20 til 31.

33. Brønntraktor ifølge krav 32, hvor anordningen er tilveiebrakt i en uttrekkbar arm (2, 102, 202) på traktoren.

34. Brønntraktor ifølge krav 32 eller 33, hvor traktoren omfatter minst ett drivhjul (4, 104, 204) og den roterbare sammenstillingen (20, 120, 220) til anordningen er koblet til drivhjulet for å frembringe fremover- eller bakoverrotasjon av drivhjulet avhengig av rotasjonen til den roterbare sammenstillingen.

35. Borehullsstreng inkludert minst én traktorseksjon, hvor traktorseksjonen inkluderer et drivhjul (4, 104, 204) montert på en ende av en arm (2, 102, 202) som er uttrekkbar fra et legeme av traktorseksjonen, idet traktorseksjonen videre inkluderer en anordning (1, 101, 201) ifølge et hvilket som helst av kravene 1 til 19 for å betjene drivhjulet.

36. Borehullsstreng ifølge krav 35, inkludert en flerhet av traktorseksjoner som henholdsvis inkluderer minst ett drivhjul montert på en ende av en arm (2, 102, 202) som er uttrekkbar fra et legeme av traktorseksjonen, hvor minst én av traktorseksjonene har en anordning (1, 101, 201) ifølge et hvilket som helst av kravene 1 til 19 hvori den minst ene porten (17, 117, 217) er stilt i den første posisjonen for å betjene et samsvarende drivhjul i en fremoverretning, og minst én annen av traktorseksjonene har en anordning (1, 101, 201) ifølge et hvilket som helst av kravene 1 til 19 hvori den minst ene porten (17, 117, 217) er stilt i den andre posisjonen for å betjene et annet samsvarende drivhjul i en bakoverretning.

37. Borehullsstreng ifølge krav 35 eller 36 som er konfigurert til å kobles til en brønnkabel.

38. Borehullsstreng ifølge krav 36 eller 37, inkludert minst ett brønnintervensjonsverktøy.

39. Fremgangsmåte for å betjene en traktor i et borehull, idet traktoren har minst én seksjon som omfatter minst ett drivhjul (4, 104, 204) montert på en ende av en arm (2, 102, 202) som kan trekkes ut fra et legeme av seksjonen, og armen inkluderer en anordning (1, 101, 201) ifølge et hvilket som helst av kravene 1 til 19, idet fremgangsmåten omfatter trinnene:

å trekke ut armen for å skyve drivhjulet mot en omgivende vegg i borehullet; å tilføre hydraulikkfluid til kammeret (58, 158, 258) på anordningen for å generere rotasjon av traktorhjulet i enten fremover- eller bakoverretningen som tilsvarer posisjonen til porten eller portene (17, 117, 217), idet hydraulikkfluidet tilføres kammeret gjennom armen.

40. Fremgangsmåte for å konfigurere en brønntraktor, idet traktoren har minst én seksjon som omfatter minst én anordning (1, 101, 201) ifølge et hvilket som helst av kravene 1 til 19 eller fordeleren (12, 112, 212) ifølge et hvilket som helst av kravene 20 til 31, idet fremgangsmåten omfatter trinnet å bevege porten (17, 117, 217) mellom den første posisjonen og den andre posisjonen for å stille porten i enten den første posisjonen for å generere fremoverbevegelse i drivhjulet (4, 104, 204) eller den andre posisjonen for å generere bakoverbevegelse i drivhjulet.

Drawings

Priority

No priority

Patent classes

IPC classes

E21B 23/04

E21B 23/00

F04B 1/06

F04B 1/107

CPC classes

E21B 23/04

E21B 2023/008

F04B 1/063

F04B 1/1071

Citations

WO 92/10677 A1 (A1)

US 2014/014365 A1 (A1)

Applicants, owners and inventors

Owners

ALTUS INTERVENTION (TECHNOLOGIES) AS

Moseidveien 35

4033 STAVANGER

NO (STAVANGER Municipality, Rogaland county)

Org. number: 915728847

Inventors

Gerald McInally

Alvevegen 5

4344 BRYNE

NO (TIME Municipality, Rogaland county)

Agent

HÅMSØ PATENTBYRÅ AS

Postboks 9

4068 STAVANGER

NO (STAVANGER Municipality, Rogaland county)

Org. number: 918752900

Reference: P28355NO00

Status history

Payment history

Oppositions and appeals

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No administrative limitation

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Only events from 2024.03.04 and onwards are shown.

Device for hydraulically operating a drive wheel of a wellbore tractor, e.g. a motor, and related...