Key information

Title
Individual or paired arm control in a wellbore tractor
Application number
20230011
Case type
National
Status
21.10.2024 Patent meddelt (B1)
Filed
06.01.2023
Effective date
06.01.2023
Publicly available
08.07.2024
Next annual fee due
31.01.2027
Applicant
WELL INNOVATION AS (NO)
Owner
Gowell Technology Norway AS (NO)
Inventor
John Robert Loxley Wood (NO)
Agent
BRYN AARFLOT AS (NO)
Granted
21.10.2024
Patent number
348235
Expiry date
06.01.2043

Abstract and drawing

Disclaimer: This text has been machine-scanned and may contain errors – please refer to "Publications" for legally binding content.
The present invention relates to an individual or paired arm control (20) in a wellbore tractor (10) being run in a borehole (30) penetrating a formation (40), as well as a wellbore tractor (10) with such an individual or paired arm control (20).

Publications

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Documents

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Date
 Date Doc. No. Process Case number In/Out Journal description To/from
 16.06.2025 02-01 Overdragelse av søknad/rettighet 2025/07310 UT GH Forespørsel BRYN AARFLOT AS
 09.06.2025 01-02 Overdragelse av søknad/rettighet 2025/07310 INN Norway - General Power of Attorney BRYN AARFLOT AS
 09.06.2025 01-01 Overdragelse av søknad/rettighet 2025/07310 INN Generell henvendelse BRYN AARFLOT AS
 02.12.2024 12-01 Saksbehandling 20230011(348235) UT PT Varsel om betaling av første årsavgift (3317) (PT20230011) BRYN AARFLOT AS
 25.10.2024 11-01 Saksbehandling 20230011(348235) UT PT Registreringsbrev nasjonal patent (15) (PT20230011)
31.07.2024 10-01 Saksbehandling 20230011 UT Intention to grant BRYN AARFLOT AS
 10.05.2024 09-05 Saksbehandling 20230011 INN 141854-Response NIPO BRYN AARFLOT AS
 10.05.2024 09-04 Saksbehandling 20230011 INN 141854-claims-no BRYN AARFLOT AS
 10.05.2024 09-03 Saksbehandling 20230011 INN 141854-amended-v2-tracked BRYN AARFLOT AS
 10.05.2024 09-02 Saksbehandling 20230011 INN 141854-amended-v2-clean BRYN AARFLOT AS
 10.05.2024 09-01 Saksbehandling 20230011 INN Korrespondanse (Hovedbrev inn) BRYN AARFLOT AS
 22.03.2024 08-01 Saksbehandling 20230011 UT Substantive examination BRYN AARFLOT AS
 20.12.2023 07-04 Saksbehandling 20230011 INN Response NIPO BRYN AARFLOT AS
 20.12.2023 07-03 Saksbehandling 20230011 INN 141854-application-amended-tracked BRYN AARFLOT AS
 20.12.2023 07-02 Saksbehandling 20230011 INN 141854-application-amended-clean BRYN AARFLOT AS
 20.12.2023 07-01 Saksbehandling 20230011 INN Korrespondanse (Hovedbrev inn) BRYN AARFLOT AS
 31.10.2023 06-01 Saksbehandling 20230011 UT PT Bekreftelse på fristutsettelse BRYN AARFLOT AS
 05.05.2023 05-02 Saksbehandling 20230011 UT PT report 10:29:00
05.05.2023 05-01 Saksbehandling 20230011 UT Substantive examination BRYN AARFLOT AS
 30.01.2023 04-02 Saksbehandling 20230011 INN Erklæring - signert BRYN AARFLOT AS
 30.01.2023 04-01 Saksbehandling 20230011 INN Korrespondanse (Hovedbrev inn) BRYN AARFLOT AS
 06.01.2023 03-01 Saksbehandling 20230011 UT Formal Examination 1 BRYN AARFLOT AS
 06.01.2023 02-01 Saksbehandling 20230011 UT Infobrev til oppfinner BRYN AARFLOT AS
 06.01.2023 01-04 Saksbehandling 20230011 INN Signert Generalfullmakt NO BRYN AARFLOT AS
 06.01.2023 01-03 Saksbehandling 20230011 INN 141854-figures-final BRYN AARFLOT AS
 06.01.2023 01-02 Saksbehandling 20230011 INN 141854-application BRYN AARFLOT AS
 06.01.2023 01-01 Saksbehandling 20230011 INN Søknadsskjema Patent BRYN AARFLOT 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
TECHNICAL FIELDThe present invention relates to newer generation wellbore conveyance systems, also known as wellbore tractors. The invention relates further to an individual or paired arm control in a wellbore tractor as well as a wellbore tractor with such an individual or paired arm control.BACKGROUND OF THE INVENTIONA wellbore tractor is a conveyance tool used in a horizontal section of an oil well to “convey” a “payload” further into the well. The “payload” could typically be logging tools for inspection of the well, perforating tools for making radially holes in the well to allow for oil to emerge, setting tools for setting plugs/patches/straddle, clean-out tools for removing debris, or manipulation tools for opening/closing valves, etc.The wellbore tractors work in a harsh environment with temperatures downhole typically in the range of 80 - 200 ºC and at pressures ranging up to typically 137,9 MPa / 1379 bar or 172,4 MPa / 1724 bar (20000 or 25000 psi). And even more extreme wells exist.A typical wellbore tractor normally has the shape of a cylindrical base where “arms” with (drive) wheels or belts, at the end, pivot out from the cylindrical body until the wheels / belts reach the inner wall of the well. The wheels or belts on the arms typically face down into the well (also called “downstream”) since if they were facing up towards the surface (also called “upstream”) they would have a higher potential of getting stuck inside the wellbore while pulling out of hole (POOH). The powertrain of the tractor is typically electro-hydraulically or electro-mechanically driven.The typical up-to-date wellbore tractor is usually powered from the surface and utilizes telemetry for communication between a surface system and a downhole tool string via an electrically powered wireline winch, also known as e-line. As previously described the purpose of the wellbore tractor is to convey various tools with different functionality to a relevant location in the well where normal tool strings relying only on gravity will not reach.The typical wellbore tractor has 2, 4, 6 or 8 wheels, where a pair of wheels are forced in opposite directions to create sufficient traction when pulling a wireline into a deviated / horizontal section of the well. Different pair of wheels can be offset by 90 degrees to improve centralization providing force in both radial axes. A pair of arms will typically either have a common pivot point or individual pivot points axially shifted in near proximity. In both cases a typical tractor would activate all arms simultaneously typically from a common hydraulic source.The wellbore tractor could work in an open hole or cased hole environment. A cased hole environment in a deviated well will typically consist of a vertical, cased wellbore with a tapered production tubing, meaning that the wellbore tractor on its way into the well will experience transitions from a larger outer diameter to a smaller outer diameter (OD). In addition, there exists other types of OD restrictions in the well, such as safety valves or other inserts that the wellbore tractor will have to maneuver through.First generation wellbore tractors were generally powered by a simple electrohydraulic drive mechanism where adjusting the power to the electromotor would allow change of speed. All wheels work simultaneously, and if one wheel fails, then all will fail. In order to provide grip towards the wellbore (typically a cased hole production tubing or even an open hole) a single hydraulic power circuit would be typically utilized to force all the arms and wheels towards the wall of the well for the purpose of creating traction for the wheels. The first-generation tractors were fully electro-hydraulic with no or very limited communication via telemetry. The typical electro-hydraulic tractor will only allow tractoring into the well (excluding reverse tractoring).Second generation wellbore tractors would typically utilize a similar electro-hydraulic (alternatively electro-mechanical) powered arm to force an individual arm or a pair of arms and wheels towards the wall of the well and use one or multiple electromotors to power either individual, paired or all wheels simultaneously for propulsion in the wellbore. Once multiple electromotors are utilized, the ability to control and get feedback from the different electromotors appears. But still, the arms are controlled simultaneously as one unit, for example via hydraulic circuitry. The second generation wellbore tractors would typically feature a telemetry function that would enable limited sensor feedback and control to surface. Here reverse tractoring is possible but not typical.Third generation wellbore tractors are fully electronically controlled robots with a local downhole master controller and higher bandwidth telemetry. The arms are still typically electro-hydraulically (alternatively electro-mechanically) actuated to provide force to the wheels. The arms, however, are typically still operated as a single system, all being activated simultaneously. The wheels are powered for propulsion in the wellbore by electromotors controlled by electronics and sensors. The speed and torque of the motors are setpoint adjusted from the surface but controlled locally by algorithms in the controller in the tractor. Reverse tractoring can be safely implemented by the use of wireline tension feedback and other sensor inputs, preventing backing over the wireline cable.WO 2018/094368 A1 describes systems for improving performance and operational efficiency of wireline tractors. A cooling system is used to improve power capabilities of electrical motors mounted in wheels, which are mounted on a linkage pivotably connected to an arm extended from a tractor tool body, in an in-line arm configuration. The linkage and arm mechanism significantly improve the tractor's ability to traverse wellbore obstructions. The hydraulic system of the tractor ensures further adequate wellbore centralization.WO 2018/067018 A1 concerns a downhole tractor having at least one hydraulic drive section, comprising a first hydraulic supply line for actuating at least one hydraulic cylinder for actuating at least one tractor arm, and a second hydraulic supply line for driving at least one hydraulic motor for rotating at least one tractor wheel. The downhole tractor further comprises a hydraulic power pack configured for supplying hydraulic fluid to the hydraulic supply lines. The hydraulic power pack comprises a pressure-setting valve provided in between the first hydraulic supply line and the second hydraulic supply line, wherein the pressure-setting valve is configured for feeding excess hydraulic fluid in the first hydraulic supply line to the second hydraulic supply line in order to increase the speed of the downhole tractor.US 2016/0290047 A1 relates to a downhole tool that has a plurality of arm assemblies. Each of the arm assemblies has an arm configured to expand and retract and an actuator. The downhole tool further comprises a hydraulic bus in fluid communication with the plurality of arm assemblies, and a plurality of flow control devices. The flow control devices are configured to selectively isolate one or more arm assemblies of the plurality of arm assemblies from the hydraulic bus while maintaining the other arm assemblies of the plurality of arm assemblies in communication with the hydraulic bus.INTRODUCTION TO THE INVENTIONAs mentioned, the wellbore tractor is utilized to convey other tools, via an electrically powered wireline winch, into an oil and gas well. The tools can typically be logging packages, perforation guns or other well intervention equipment. The wellbore will typically be a long vertical wellbore ending up in a deviated and/or horizontal section where propulsion assistance will be required in order to reach a target. When entering the wellbore and on its way into the wellbore the tractor will have to function properly and will also have to pass potential restrictions and transitions from larger outer diameter to smaller outer diameter wellbores. If not successfully negotiated the mission fails. The mission into the wellbore will typically take many hours, so any improvement related to efficiency and risk reduction will be highly beneficial.During a mission there are multiple other things that can go wrong which again, depending on severity, could cause a mission abort.If for example an individual wheel fails, the wheel would be stuck towards the cased hole preventing efficient propulsion, causing excessive friction and subsequently potential mission abort. Loss of propulsion in general will likely cause mission failure. SUMMARY OF THE INVENTIONThe present invention relates to the latest third generation of wellbore tractors, where the wheels are powered either individually or in pairs of 2 (but also a set of 3 and 4 wheels) and controlled by a local downhole master controller and also featuring / having a higher bandwidth telemetry.It is an object of the invention to provide individual or paired arm control, mainly for the purpose and advantage of improved negotiation of wellbore restrictions.Another object of the invention is to provide tailored sets of arms for different applications or different wellbore sizes.Yet another object of the invention is to allow a failed wheel to be retracted and disabled individually (or in pairs of 2, 3, 4 wheels) for the purpose of being able to continue tractor operation.The main features of the present invention are given in the independent claims. Additional features of the invention are given in the dependent claims.According to a first aspect of the invention this is achieved with an individual or paired arm control in a wellbore tractor.According to a second aspect of the invention this is achieved with a wellbore tractor with an individual or paired arm control.The present invention teaches an independent or paired arm control system configured for a wellbore tractor configured to be run in a borehole penetrating a formation. The control system comprises:- a 3-port/2-way normally open solenoid valve arranged in a drive module of the wellbore tractor, the drive module having at least one arm with at least one wheel or belt, - a hydraulic cylinder-piston assembly comprising a hydraulic cylinder with an actuator piston and a retraction spring arranged therein, the hydraulic cylinder-piston assembly arranged within the drive module,- a hydraulic pressure line connected to a hydraulic pump configured to provide high pressure by means of a hydraulic fluid,- a return hydraulic line connected to a reservoir configured for containing the hydraulic fluid,- wherein a control port of the 3-port/2-way normally open solenoid valve is connected to the hydraulic cylinder of the hydraulic cylinder-piston assembly, a return port of the 3-port/2-way normally open solenoid valve is connected to the return hydraulic line, and a pressure port of the 3-port/2-way normally open solenoid valve is connected to the hydraulic pressure line.The independent or paired arm control system can further comprise a 3-port/2-way normally closed fail-safe solenoid valve, wherein a control port of the 3-port/2-way normally closed fail-safe solenoid valve is connected to the 3-port/2-way normally open solenoid valve via the pressure port of the 3-port/2-way normally open solenoid valve; a return port of the 3-port/2-way normally closed fail-safe solenoid valve is connected to the return hydraulic line; and a pressure port of the 3-port/2-way normally closed fail-safe solenoid valve is connected to the hydraulic pressure line having the hydraulic pump.The hydraulic pump can be driven by an electrical motor that can be controlled by a motor controller.The independent or paired arm control system can further comprise a pressure safety valve connected between the hydraulic pressure line and the return hydraulic line.The independent or paired arm control system can further comprise a check valve arranged in the hydraulic pressure line and between the hydraulic pump and the 3-port/2-way normally closed fail-safe solenoid valve. The independent or paired arm control system can further comprise a pressure/temperature sensor connected to the hydraulic pressure line and configured to monitor the pressure in the hydraulic pressure line.The independent or paired arm control system can further comprise a pressure compensation unit comprising the (oil sump) reservoir (containing the hydraulic fluid), a spring activated piston (i.e. a compensator spring and a compensator piston) and a ventilation port.Said at least one arm can be arranged in at least one pair of arms having at least one of: i) a common pivot point and/or ii) individual pivot points axially shifted in near proximity. The common pivot point type or version can have a single actuator (or also called “actuator unit”) for a pair of arms. The axially shifted type or version can have an individual actuator (unit) for each arm.The invention teaches also a wellbore tractor configured to be run in a borehole penetrating a formation, wherein the wellbore tractor comprises said independent or paired arm control system.BRIEF DESCRIPTION OF THE DRAWINGSThese and other aspects of the invention are apparent from and will be further elucidated, by way of example(s), with reference to the drawings, wherein:Figures 1A-1G show the working principle of the present invention.Figures 2A-2C show a drive module of a wellbore tractor according to the invention under different operational conditions.Figures 2D-2F show a solenoid valve in the drive module of the wellbore tractor of figures 2A-2C under different operational conditions.Figures 3A-3B show a hydraulic power module (HPM) of the wellbore tractor according to the invention in two different states.Figure 4 shows a detailed piping and instrumentation diagram (P&ID) of the wellbore tractor according to the invention. DETAILED DESCRIPTION OF THE EMBODIMENTSBelow there will be described several scenarios pointing out the advantages of the present invention.Scenario 1: The wellbore tractor is struggling to get into a restriction in the wellbore, and traditionally would need to abort mission and pull out. Prior to aborting the mission, the operator has likely performed multiple attempts to succeed. These attempts are associated with high risk of excessive wear, or even damage, to both the tractor / tool string, restriction and wellbore. With an individual or paired arm control according to the invention a first individual arm or first pair / set of arms could be retracted to allow easier and less aggressive access into the restriction. The remaining arms will provide traction into the restriction. Once the first arm or pair of arms is inside or has passed the restriction, the arm(s) can be activated again. The process can then be repeated for the next individual or pair of wheels and so on, until all wheels have passed through the restriction. This has traditionally been solved by running two tractors in “tandem”.Scenario 2: If, for some reason the wellbore tractor has a failure that causes a wheel to stop, this would traditionally need to abort the mission and pull out. With the individual or paired arm control according to the invention, the affected wheel and arm or the affected pair of wheels and arms can be retracted and disabled, allowing the remaining wheels a better chance of completing the mission.Scenario 3: During the “run-in-hole” period the focus for the wireline tractor is speed and sufficient torque to convey the tool string into the deviated portions of the well. But, for fine adjustments close to target it could be envisioned that the focus should be ultra-fine speed and high torque, below the range of what would be possible with a high-speed motor. This could for example be solved by introducing a gearbox for “high” and “low” gear, but this might not be feasible due to the size constraints (fixed limited diameter, length can more easily be adjusted). It could therefore be envisioned that the individual or paired arm control according to the present invention could be utilized to power for example two different sets of arms with different characteristics, typically “high speed/limited torque” and “low speed/high torque”. A second possibility is that this function could also be utilized for different sizes of the wellbore, where the different arm sets are tailored specifically for different wellbore sizes or a range of wellbore sizes.This individual or paired arm control action could be electronically controlled as an algorithm but could also be performed manually via a communication system (e.g., telemetry) from the surface.The present invention gives the ability of disabling / enabling any arm from being driven in or out of the tool independently to have the ability to either: disable an arm, in the event of a motor/gear/electrical failure without aborting the tractor operation, or to be able to independently disable/enable arms when overcoming an obstruction in the well which normally would prohibit the tractor from passing or would alternatively require two tractors to run in “tandem” in order to achieve the same result.The present invention also opens up to equip a tractor with multiple sets of arms with different characteristics tailored for e.g. different size wellbores, speeds, push/pull force(s).The main principle of the present invention will be described below with respect to the first scenario mentioned above and with reference to some of the drawings (figures 1A-1G).A wellbore tractor can comprise a system control module (SCM) 24 having electronics, several drive modules (DM) and a hydraulic power module (HPM). The wellbore tractor 10 is connected to the surface via a wireline 60.Figure 1A illustrates a wellbore tractor 10 having, in this example, four drive modules (DM) 13A, 13B, 13C, 13D with drive arms 12A, 12B, 12C, 12D with wheels 11A, 11B, 11C, 11D. The drive arms 12A, 12B, 12C, 12D with drive wheels 11A, 11B, 11C, 11D are illustrated enabled or extracted thus providing grip towards a wall 35 of a wellbore 30 in a formation 40. The wellbore tractor 10 uses an independent or paired arm control 20 (figures 2A-2C) to pass through an obstruction 50, which normally would prevent a typical wellbore tractor from getting through the obstruction 50 as the wheels of the typical wellbore tractor are not able to climb the obstruction 50 by themselves.When a lower-most or first wheel 11A of the wellbore tractor 10 hits the obstruction 50 the independent or paired arm control 20 (figures 2A-2C) will disable simultaneously a lower-most or first arm 12A and its neighbor or second arm 12B (i.e. a lower-most or first pair of arms 12A, 12B) and these two arms 12A, 12B will be retracted, as illustrated in figure 1B.Then the wellbore tractor 10, with the help of the other two drive modules 13C, 13D having arms 12C, 12D with wheels 11C, 11D, will be able to run further into the obstruction 50 with the length of the two disabled drive modules 13A, 13B, as illustrated on figure 1C.Then the first and second arms 12A, 12B will be enabled, i.e. extracted, to provide grip towards a wall 55 of the obstruction 50, as illustrated on figure 1D.When the third wheel 11C of the third drive arm 12C hits the obstruction 50 (figure 1D) the independent or paired arm control 20 (figures 2A-2C) will disable simultaneously the third arm 12C and the fourth arm 12D (i.e. the second pair of arms 12C, 12D) getting these two arms 12C, 12D retracted (figure 1E). This allows the wellbore tractor 10, with the help of the first and second drive modules 13A, 13B, to run further into the obstruction 50 with the length of the two disabled drive modules 13C, 13D (figure 1F). Finally, the third and fourth arms 12C, 12D will be enabled / extracted to provide grip towards the wall 55 of the obstruction 50 (figure 1G) and the tractor 10 will continue its journey down the wellbore 30.In another embodiment of the invention, the independent or paired arm control 20 can be configured to individually control each arm 12A, 12B, 12C, 12D of the wellbore tractor 10, and not a pair of arms as described above. Of course, the independent or paired arm control 20 can be configured to individually control a set of several (more than two) arms of the wellbore tractor 10.Figures 2A-2C show one of the drive modules 13A, 13B, 13C, 13D of the wellbore tractor 10 under different operations or working conditions.The drive module 13A, 13B, 13C, 13D comprises an actuator (also called “an actuator unit” or “a hydraulic cylinder-piston assembly”) comprising a hydraulic cylinder 17 having an actuator piston 36 and a retraction spring 18 arranged therein. The retraction spring 18 can retract the arm 12A, 12B, 12C, 12D when it is disabled, i.e. when it loses hydraulics. Also, in a default position, the retraction spring 18 in the cylinder 17 of the actuator unit keeps the arm 12A, 12B, 12C, 12D retracted (figure 2A).The individual or paired arm control 20 is making the control by utilizing a set of solenoid valves 14 located in each drive module 13A, 13B, 13C, 13D. These solenoid valves 14 are connected to a tractor/system controller 26 (located in the system control module (SCM) 24 of the wellbore tractor 10). The solenoids / solenoid valves 14 can be controlled based on sensor inputs (such as, but not limited only to, for example motor torque, motor speed, accelerometer, gyro, tension, proximity, pressure, etc.) and/or algorithms and/or manually from the surface via a communication system (telemetry).The solenoid valve 14 in each drive module 13A, 13B, 13C, 13D is by default not activated (i.e. without supplied power thereto) as shown in figure 2A. Then, in order to facilitate normal operation of the tractor 10, pressure from system hydraulics will go through a hydraulic pressure line 21 to the actuator with the piston 36 and cylinder 17 that will activate the arm 12A - 12D as shown in figure 2B. When any of the solenoid valves 14 is activated (i.e. power is supplied thereto), the valve 14 will then close the access of the system hydraulics to the respective cylinder 17 and the hydraulic fluid will be guided through a return hydraulic line 22 back to a reservoir 19 (figure 3A) in the hydraulic power module (HPM) 25. Then the selected cylinder(s) 17 will lose pressure, and the corresponding arm(s) 12A - 12D will be deactivated and so retracted by means of the retraction spring(s) 18 back into the drive module(s) 13A - 13D as illustrated on figure 2C.According to one embodiment, the above-mentioned process can be controlled from the surface, where an operator will, after the obstruction 50 is located and/or observed, stop and reverse the tractor 10 a controlled distance up from the obstruction 50. Then the operator will deactivate the first set of arms (e.g.12A, 12B), either individually or in pairs, in order to drive the tractor 10 into the obstruction 50 with the remaining arms (e.g.12C, 12D) which are activated. The tractor 10 will proceed further with the same controlled distance plus a selected distance in order to ensure that the deactivated arms (e.g.12A, 12B) have passed the obstruction 50. Then the arms (e.g.12A, 12B) that have passed the obstruction 50 are activated by the operator, and the operator will deactivate the next set of arms (e.g.12C, 12D) that will then pass the obstruction 50. The next set of arms (e.g.12C, 12D) that have passed the obstruction 50 will then, along with any available activated arms above and/or below (e.g.12A, 12B) the obstruction 50, be used to drive the tractor 10 through the obstruction 50. See also figures 1A-1G.Alternatively, according to another embodiment, the above-described process can be an automated process carried out by use of algorithm(s) based on sensor inputs (such as, but not limited only to, for example motor torque, motor speed, accelerometer, gyro, tension, proximity, pressure, etc.). This can also or alternatively be incorporated as a fully automated process based on sensor inputs and/or wellbore characteristics where the system automatically selects the optimal algorithm for negotiating known or unknown obstruction(s) / feature(s) in the well. A known obstruction can be planned based on wellbore characteristics (and real-time sensor inputs), but an unknown obstruction would rely solely on real-time sensor inputs. The advantages of implementing such a system would allow for a less aggressive (and more gentle) operation resulting in less downtime and wear/damage to the wellbore and tractor / tool string.Figures 2D-2F show the different states and ports (P: pressure, C: control and R: return) of the solenoid valve 14. Figure 2D shows the default state (where the solenoid valve 14 is not activated, no pressure, and the arms are retracted - figure 2A). Figure 2E shows a normal operation (where the solenoid valve 14 is not activated, with pressure on the actuator, and the arms are extended - figure 2B). And figure 2F shows the individual arm control state (where the solenoid valve 14 is activated, the pressure on the actuator is switched off, and the individual arm is retracted - figure 2C).Figures 3A-3B show the hydraulic power module (HPM) 25 of the wellbore tractor 10, where figure 3A shows a system 3-way fail-safe valve 23 in a default state (where the fail-safe valve 23 is not activated and the arms are retracted - see also figure 2A), and figure 3B shows the 23 fail-safe valve in an active state (where the fail-safe valve 23 is activated and the arms are extended (or the individual arms are retracted if the solenoid valves 14 are activated) - see also figure 2B (and figure 2C)).The hydraulic power module (HPM) 25 comprises an electrical motor 28 driving a hydraulic pump 29 creating high pressure to hydraulic high-pressure line 21. The high-pressure line 21 is monitored by a pressure/temperature sensor 31, which again can be used as sensor input(s) for control of the hydraulic system. The electrical motor 28 can be controlled by a motor controller 15. The motor controller 15 can be arranged close to or adjacent to and is connected to the electrical motor 28.A pre-set hydraulic-mechanic pressure relief valve (also called a pressure safety valve) 27 is further included as a part of the high-pressure line 21 to allow for a quick bleeding of hydraulic fluid in case of an extraordinary pressure build-up.Due to the tractor 10 operating in a high pressure/temperature downhole environment and also due to the tractor 10 also operating over a wide pressure range (from ambient surface pressure/temperature to high pressure/temperature downhole conditions), the hydraulic system needs to be pressure compensated (towards the pressure in the wellbore 30) due to thermal oil expansion and control of differential pressure (between the hydraulic lines in the system and the wellbore pressure). This is achieved with a spring 33 activated piston 34 creating a slightly higher pressure in the oil sump reservoir 19 compared to the pressure in the wellbore 30. A ventilation port 32 allows access to fluid pressure from the wellbore 30 to activate the piston 34.Figure 4 shows a detailed piping and instrumentation diagram (P&ID) of the wellbore tractor 10.The hydraulic schematic system diagram (P&ID) for the wellbore tractor 10 illustrates the option to disconnect one or more of the tractor’s 10 drive arms 12A, 12B, 12C, 12D without affecting the remaining arms so that the remaining arms can continue the operation of the tractor 10.This is done by activating one of the solenoid valves 14, each being 3-port/2-way normally open solenoid valve 14 (abbreviated as 3/2 NO valve), according to the hydraulic schematics diagram (figure 4), so that a cylinder 17 loses pressure and contracts to its starting or closed or deactivated position resulting in that the arm 12 retracts. The contraction can be provided by the built-in retraction spring 18, and the hydraulic fluid that is inside the cylinder 17 bleeds off to the reservoir 19 in the hydraulic power module (HPM) 25 (figures 3A-3B).The system 3-way fail-safe valve (being 3-port/2-way normally closed solenoid valve (abbreviated as 3/2 NC valve)) 23 can be arranged or placed in the hydraulic power module (HPM) 25 of the tractor 10. The system 3-way fail-safe valve 23 is being activated by default under a normal operation (to activate all arms 12A, 12B, 12C, 12D). If this fail-safe valve 23 is being deactivated or loses power, all arms 12A, 12B, 12C, 12D will retract independently of the position of the individual valve 14 (3/2 NO valve) in each arm 12A-12D. This provides as a fail-safe feature in the event of issues or loss of power to the wellbore tractor 10. This fail-safe valve 23 has also ports C, P, R as the solenoid valve 14.A check valve 16 can be arranged as a part of the hydraulic pressure line 21 and between the hydraulic pump 29 and the 3-way fail-safe solenoid valve 23. The check valve 16 is configured to maintain the high pressure when the hydraulic pump 29 is not active. The pre-set hydraulic-mechanic pressure relief valve (pressure safety valve) 27, included as a part of the high-pressure line 21, allows for a quick bleeding of the hydraulic fluid if a tractor arm 12A-12D unexpectedly should collide with the obstruction 50 in the well 30 so that an extraordinary pressure will be built-up as a result of excessive flow resistance. The pressure safety valve 27 is set to a selected maximum pressure which will open at this selected maximum pressure so that the system pressure will not become very high and will not damage any components thereof.The present invention covers also tractors 10 with a common pivot point.Two or more wellbore tractors 10 can be run in tandem and controlled in the previously described manner.Additional modifications, alterations and adaptations of the present invention will suggest themselves to those skilled in the art without departing from the scope of the invention as defined in the following patent claims.List of componentsA wellbore tractor 10Wheels 11A, 11B, 11C, 11DArms 12A, 12B, 12C, 12DDrive modules 13A, 13B, 13C, 13DA solenoid valve / 3-port/2-way normally open solenoid valve (3/2 NO valve) 14 A motor controller 15A check valve 16A hydraulic cylinder 17 with a retraction spring 18 therein (a part of an actuator (also called an actuator unit))A retraction spring 18 (a part of the actuator (unit))A reservoir / an oil sump reservoir 19 having a hydraulic fluidAn independent or paired arm control 20A hydraulic pressure line 21 A return hydraulic line 22A 3-way fail-safe solenoid valve 23A system control module (SCM) 24A hydraulic power module (HPM) 25A tractor/system controller 26A pressure safety valve 27An electrical motor 28A pump / a hydraulic pump 29A wellbore 30A pressure/temperature (PT) sensor 31A wellbore ventilation port 32A compensator spring 33 (shown in figure 3A)A compensator piston 34 (shown in figure 3A)A wall 35 of the wellbore 30An actuator piston 36 (a part of the actuator (unit)) A formation 40An obstruction 50A wall 55 of the obstruction 50A wireline 60
Claims
CLAIMS1. An independent or paired arm control system (20) configured for a wellbore tractor (10) configured to be run in a borehole (30) penetrating a formation (40), the control system (20) comprising:- a 3-port/2-way normally open solenoid valve (14) arranged in a drive module (13A, 13B, 13C, 13D) of the wellbore tractor (10), the drive module (13A, 13B, 13C, 13D) having at least one arm (12A, 12B, 12C, 12D) with at least one wheel (11A, 11B, 11C, 11D) or belt,- a hydraulic cylinder-piston assembly comprising a hydraulic cylinder (17) with an actuator piston (36) and a retraction spring (18) arranged therein, the hydraulic cylinder-piston assembly (17, 18, 36) arranged within the drive module (13A, 13B, 13C, 13D),- a hydraulic pressure line (21) connected to a hydraulic pump (29) configured to provide high pressure by means of a hydraulic fluid,- a return hydraulic line (22) connected to a reservoir (19) configured for containing the hydraulic fluid, and- a control port (C) of the 3-port/2-way normally open solenoid valve (14) is connected to the hydraulic cylinder (17) of the hydraulic cylinder-piston assembly (17, 18, 36), a return port (R) of the 3-port/2-way normally open solenoid valve (14) is connected to the return hydraulic line (22), and a pressure port (P) of the 3-port/2-way normally open solenoid valve (14) is connected to the hydraulic pressure line (21),wherein the hydraulic cylinder (17) and the actuator piston (36) are configured to keep said at least one arm (12A, 12B, 12C, 12D) activated by means of the high pressure of the hydraulic fluid going, through the hydraulic pressure line (21), to the hydraulic cylinder-piston assembly with the hydraulic cylinder (17) and the actuator piston (36), andwherein when activated the 3-port/2-way normally open solenoid valve (14) is configured to independently deactivate its corresponding at least one arm (12A, 12B, 12C, 12D), resulting in that said corresponding at least one arm (12A, 12B, 12C, 12D) is retracted by means of its corresponding retraction spring (18), and the 3-port/2-way normally open solenoid valve (14) closes the access of the hydraulic fluid to the respective hydraulic cylinder (17), and the hydraulic fluid is guided through the return hydraulic line (22) back to the reservoir (19).2. The independent or paired arm control system (20) according to claim 1, further comprising: a 3-port/2-way normally closed fail-safe solenoid valve (23), wherein a control port (C) of the 3-port/2-way normally closed fail-safe solenoid valve (23) is connected to the 3-port/2-way normally open solenoid valve (14) via the pressure port (P) of the 3-port/2-way normally open solenoid valve (14); a return port (R) of the 3-port/2-way normally closed fail-safe solenoid valve (23) is connected to the return hydraulic line (22); and a pressure port (P) of the 3-port/2-way normally closed fail-safe solenoid valve (23) is connected to the hydraulic pressure line (21) having the hydraulic pump (29).3. The independent or paired arm control system (20) according to claim 1 or 2, further comprising a pressure safety valve (27) connected between the hydraulic pressure line (21) and the return hydraulic line (22).4. The independent or paired arm control system (20) according to any one of the preceding claims, wherein the hydraulic pump (29) is driven by an electrical motor (28).5. The independent or paired arm control system (20) according to any one of the preceding claims, further comprising a check valve (16) arranged in the hydraulic pressure line (21) and between the hydraulic pump (29) and the 3-port/2-way normally closed fail-safe solenoid valve (23).6. The independent or paired arm control system (20) according to any one of the preceding claims, further comprising a pressure/temperature sensor (31) connected to the hydraulic pressure line (21) and configured to monitor the pressure in the hydraulic pressure line (21).7. The independent or paired arm control system (20) according to any one of the preceding claims, further comprising a pressure compensation unit comprising an oil sump reservoir (19), a spring (33) activated piston (34) and a ventilation port (32).8. The independent or paired arm control system (20) according to any one of the preceding claims, wherein said at least one arm (12A, 12B, 12C, 12D) is arranged in at least one pair of arms (12A, 12B, 12C, 12D) having one of: i) a common pivot point and ii) individual pivot points axially shifted in near proximity.9. The independent or paired arm control system (20) according to claim 8, wherein the common pivot point type has a single actuator (17, 18, 36) for a pair of arms (12A, 12B, 12C, 12D) and the axially shifted type has an individual actuator (17, 18, 36) for each arm (12A, 12B, 12C, 12D).10. A wellbore tractor (10) configured to be run in a borehole (30) penetrating a formation (40), wherein the wellbore tractor (10) comprises an independent or paired arm control system (20) according to any one of the preceding claims.PATENTKRAV1. Et uavhengig eller paret armkontrollsystem (20) som er konfigurert for en brønntraktor (10) som er konfigurert til å kjøres inn i et borehull (30) som penetrerer en formasjon (40), idet kontrollsystemet (20) omfatter:- en 3-port/2-veis normalt åpen magnetventil (14) som er anordnet i en drivmodul (13A, 13B, 13C, 13D) for brønntraktoren (10), idet drivmodulen (13A, 13B, 13C, 13D) har minst én arm (12A, 12B, 12C, 12D) med minst ett hjul (11A, 11B, 11C, 11D) eller belte,- en hydraulisk sylinder-stempel-sammenstilling som omfatter en hydraulisk sylinder (17) med et aktuatorstempel (36) og en tilbaketrekkingsfjær (18) anordnet deri, idet den hydrauliske sylinder-stempel-sammenstillingen (17, 18, 36) er anordnet inne i drivmodulen (13A, 13B, 13C, 13D),- en hydraulisk trykkledning (21) som er koblet til en hydraulisk pumpe (29) som er konfigurert til å tilveiebringe høyt trykk ved hjelp av et hydraulisk fluid,- en hydraulisk returledning (22) som koblet til et reservoar (19) som er konfigurert til å inneholde det hydrauliske fluidet, og- en kontrollport (C) til den 3-port/2-veis normalt åpne magnetventilen (14) er koblet til den hydrauliske sylinderen (17) til den hydrauliske sylinder-stempelsammenstillingen (17, 18, 36), en returport (R) til den 3-port/2-veis normalt åpne magnetventilen (14) er koblet til den hydrauliske returledningen (22), og en trykkport (P) til den 3-port/2-veis normalt åpne magnetventilen (14) er koblet til den hydrauliske trykkledningen (21),hvor den hydrauliske sylinderen (17) og aktuatorstempelet (36) er konfigurert til å holde den minst ene arm (12A, 12B, 12C, 12D) aktivert ved hjelp av det høye trykket til det hydrauliske fluidet som går, gjennom den hydrauliske trykkledningen (21), til den hydrauliske sylinder-stempel-sammenstillingen med den hydrauliske sylinderen (17) og aktuatorstempelet (36), oghvor, når den er aktivert, er den 3-port/2-veis normalt åpne magnetventilen (14) konfigurert til å uavhengig deaktivere sin tilsvarende minst ene arm (12A, 12B, 12C, 12D), noe som resulterer i at den tilsvarende minst ene arm (12A) , 12B, 12C, 12D) trekkes tilbake ved hjelp av sin tilsvarende tilbaketrekkingsfjær (18), og den 3-port/2-veis normalt åpne magnetventilen (14) stenger tilgangen til det hydrauliske fluidet til den respektive hydrauliske sylinderen (17) ), og det hydrauliske fluidet ledes gjennom den hydrauliske returledningen (22) tilbake til reservoaret (19).2. Det uavhengige eller parete armkontrollsystemet (20) i henhold til krav 1, videre omfattende: en 3-port/2-veis normalt lukket feilsikker magnetventil (23), hvor en kontrollport (C) til den 3-port/2-veis normalt lukkede feilsikre magnetventilen (23) er koblet til den 3-port/2-veis normalt åpne magnetventilen (14) via trykkporten (P) til den 3-port/2-veis normalt åpne magnetventilen (14); en returport (R) til den 3-port/2-veis normalt lukkede feilsikre solenoidventilen (23) er koblet til den hydrauliske returledningen (22); og en trykkport (P) til den 3-port/2-veis normalt lukkede feilsikre solenoidventilen (23) er koblet til den hydrauliske trykkledningen (21) som har den hydrauliske pumpen (29).3. Det uavhengige eller parete armkontrollsystemet (20) i henhold til krav 1 eller 2, videre omfattende en trykksikkerhetsventil (27) som er koblet mellom den hydrauliske trykkledningen (21) og den hydrauliske returledningen (22).4. Det uavhengige eller parete armkontrollsystemet (20) i henhold til et hvilket som helst av de foregående kravene, hvor den hydrauliske pumpen (29) er drevet av en elektrisk motor (28).5. Det uavhengige eller parete armkontrollsystemet (20) i henhold til et hvilket som helst av de foregående kravene, videre omfattende en tilbakeslagsventil (16) som er anordnet i den hydrauliske trykkledningen (21) og mellom den hydrauliske pumpen (29) og den 3-port/2-veis normalt lukkede feilsikre magnetventilen (23).6. Det uavhengige eller parete armkontrollsystemet (20) i henhold til et hvilket som helst av de foregående kravene, videre omfattende en trykk/temperatur-sensor (31) som er koblet til den hydrauliske trykkledningen (21) og konfigurert til å overvåke trykket i den hydrauliske trykkledningen (21).7. Det uavhengige eller parete armkontrollsystemet (20) i henhold til et hvilket som helst av de foregående kravene, videre omfattende en trykkompensasjonsenhet som omfatter et oljekumreservoar (19), et fjær- (33) aktivert stempel (34) og en ventilasjonsport (32).8. Det uavhengige eller parete armkontrollsystemet (20) i henhold til et hvilket som helst av de foregående kravene, hvor den minst ene arm (12A, 12B, 12C, 12D) er anordnet i minst ett par av armer (12A, 12B, 12C, 12D) som har ett av: i) et felles dreiepunkt og ii) individuelle dreiepunkter som er aksialt forskjøvet i nærheten.9. Det uavhengige eller parete armkontrollsystemet (20) i henhold til krav 8, hvor den felles dreiepunkttypen har en enkelt aktuator (17, 18, 36) for et par av armer (12A, 12B, 12C, 12D) og den aksialt forskjøvne typen har en individuell aktuator (17, 18, 36) for hver arm (12A, 12B, 12C, 12D).10. En brønntraktor (10) som er konfigurert til å kjøres i et borehull (30) som penetrerer en formasjon (40), hvor brønntraktoren (10) omfatter et uavhengig eller paret armkontrollsystem (20) i henhold til et hvilket som helst av de foregående kravene.
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Priority

No priority

Patent classes

IPC classesE21B 23/00E21B 23/14CPC classesE21B 23/001E21B 23/14

Citations

WO 2018/094368 A1 (A1)WO 2018/067018 A1 (A1)US 2016/0290047 A1 (A1)

Applicants, owners and inventors

Owners
Gowell Technology Norway AS
Koppholen 19 4313 SANDNES NO (SANDNES Municipality, Rogaland county)Org. number: 934938844Inventors
John Robert Loxley Wood
Nordhusvika 5 4150 RENNESØY NO (STAVANGER Municipality, Rogaland county)

Agent

BRYN AARFLOT AS
BRYN AARFLOT AS

Org. number: 979993269

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Stortingsgata 8 0161 OSLO NO (OSLO Municipality, Oslo county)
Org. number: 979993269
Reference: 141854/NDN

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