Autonomous systems and methods for wellbore intervention

An autonomous intervention system configured to perform an intervention operation in a wellbore comprises a tool housing having a tool storage compartment configured to house an intervention tool. A valve arrangement permits selective communication of tools and fluid between the tool housing and the wellbore. The intervention system is configured to move in response to an activation event between a tool storage configuration in which the tool housing is isolated from the wellbore by the valve arrangement and an activated configuration in which the valve arrangement is open and the tool housing communicates with the wellbore to permit deployment of the intervention tool by a tool deployment arrangement.

This application claims priority to PCT Patent Appln. No. PCT/GB2018/052407 filed Aug. 24, 2018, which claims priority GB Patent Appln. No. 1713714.2 filed Aug. 25, 2017, which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Technical Field

This relates to autonomous systems and methods for wellbore intervention.

2. Background Information

In the oil and gas industry, well boreholes (“wellbores”) are drilled in order to access subsurface hydrocarbon-bearing formations. In order to control production from a given wellbore, a valve arrangement known as a Christmas tree is typically disposed on the wellhead, the valve arrangement comprising a number of flow control valves and safety valves configured amongst other things to control production, permit well isolation and control access of downhole tools and equipment into/from the wellbore.

During the operational life of a given well, it may be necessary to access the wellbore in order to perform remedial operations, known generally in the industry as intervention or workover operations.

However, while necessary, intervention operations pose a number of challenges for operators. For example, wellbores may be located in remote or relatively inaccessible locations, making them difficult and time consuming to access, particularly for intervention operations which require significant man-power to operate and/or which require equipment which by virtue of size or weight may be restricted or prevented by local infrastructure laws. Wellbores may also be located in areas of particular scientific or environmental sensitivity. The given location may also pose challenges in terms of how to protect the environment, intervention equipment and personnel.

An operator may wish to carry out intervention operations a number of times in order to mitigate deferred production or otherwise maintain production at optimal levels. One such intervention operation involves the removal of paraffin wax, asphaltenes and/or other solids, residues and the like which can accumulate in the wellbore over time and which reduce production or otherwise reduce the optimal operation of the well. In some instances, a given field may include a significant number of wells, some fields having hundreds of wells, making intervention operations difficult and in some cases prohibitively expensive to carry out regularly given the above factors and demands on personnel and equipment.

SUMMARY OF THE INVENTION

According to a first aspect, there is provided an autonomous intervention system for a wellbore, the intervention system comprising: a tool housing configured to house an intervention tool for deployment into the wellbore; a tool deployment arrangement for deploying the intervention tool into the wellbore, wherein the intervention system is configurable between a tool storage configuration in which the tool housing is isolated from the wellbore and an activated configuration in which the tool housing communicates with the wellbore and permits deployment of the intervention tool by the tool deployment arrangement; and a controller configured to permit autonomous control of operation of the intervention system between the tool storage configuration and the activated configuration to facilitate deployment of the intervention tool into the wellbore.

Beneficially, embodiments of the intervention system permit wellbore integrity to be managed and production maintained safely and efficiently while at the same time permitting intervention operations, such as paraffin wax cleaning operations for example, to be carried out autonomously. Moreover, embodiments of the intervention system may reduce the environmental impact on the surrounding environment, for example reducing the requirement for large and heavy vehicles; reduce carbon emissions, and noise. Vehicle fleet management and personnel costs may also be reduced. The system may be configured to operate automatically and independently of any manual intervention, and configured to deploy specialist tools or tooling, for example to prevent solids build up, gather data or reconfigure a wellbore completion, saving costs, reducing health and safety and optimizing or at least improving production up-time.

In use, the intervention system may be configured to provide selective communication between the tool housing and the wellbore to permit deployment of the intervention tool into the wellbore by the tool deployment arrangement. The intervention system may permit a plurality of intervention operations to be carried out on the wellbore.

In particular embodiments, the intervention system may comprise a permanent installation. By providing a permanent installation the intervention system may be stationed during construction and/or commissioning of the wellbore and may be retained in place for the operational life of the wellbore; obviating or at least mitigating the need to transport intervention equipment to site and thereby minimizing disruption to the local environment, wildlife and infrastructure.

Alternatively, the intervention system may comprise a semi-permanent installation. For example, the intervention system may be retained in place for one or more phases of the operational life of the wellbore.

The intervention system may be configured to automatically move between the tool storage configuration and the activated configuration.

The intervention system may also or alternatively be configured to move in response to a control command from an operator. Beneficially, embodiments of the intervention system permit autonomous operation while also permitting manual intervention where required.

The controller may be configured to activate the intervention system in response to a given activation event. The activation event may be pre-determined.

The activation event may take a number of different forms.

The activation event may relate to fluid flow.

The fluid flow rate may comprise production flow rate for example.

In particular embodiments, the activation event may comprise a fluid flow rate dropping below a selected threshold. The intervention system may for example be configured to activate in response to the production flow rate from the well dropping below a threshold in order to increase production from a well. Beneficially, such operations can be carried out autonomously and without the requirement to repeatedly transport personnel and equipment to/from site, reducing the costs and challenges associated with the intervention operation and environmental impact on the surrounding environment, wildlife and infrastructure.

The activation event may comprise a fluid flow rate reaching or exceeding a selected threshold.

The activation event may comprise a fluid flow rate decrease.

The activation event may comprise a fluid flow rate dropping below a selected threshold.

The activation event may comprise a time event. For example, the intervention system may be configured to activate after a selected time has elapsed, or at a given time of day. Beneficially, embodiments of the intervention system may permit an intervention operation schedule to be implemented autonomously and without the requirement to repeatedly transport personnel and equipment to/from site, reducing the costs and challenges associated with the intervention operation and environmental impact on the surrounding environment and wildlife.

The activation event may comprise a pressure event.

The pressure event may comprise a differential pressure.

In particular embodiments, the activation event may comprise a pressure, such as differential pressure, reaching or exceeding a selected threshold.

In some embodiments, the activation event may comprise a pressure, such as differential pressure, dropping below a selected threshold.

The activation event may comprise a temperature event.

In particular embodiments, the activation event may comprise a temperature reaching or exceeding a selected threshold.

In some embodiments, the activation event may comprise a temperature dropping below a selected threshold.

The intervention system may be activated in response to a single activation event or a plurality of activation events, for example, but not exclusively, one or more of the activation events described above.

The controller may be configured to activate the intervention system in response to a single activation event or a plurality of activation events, for example, but not exclusively, one or more of the activation events described above.

As described above, the tool housing is configured to house one or more intervention tool for deployment into the wellbore.

In particular embodiments, the tool housing may comprise a lubricator.

The tool housing may be configured for location on, or may form part of, a wellhead.

In embodiments where the tool housing is adapted for location on the wellhead, the intervention system, e.g. the tool housing, may comprise a coupling arrangement for coupling the tool housing, e.g. the lubricator, to the wellhead.

In particular embodiments, the tool housing may be configured for location on a well valve arrangement, in particular but not exclusively a Christmas tree, disposed on the wellhead.

The intervention system may be configured to prevent fluid communication between the tool housing and the wellbore.

The intervention system may be configured to prevent fluid communication between the tool housing and the wellhead and/or the well valve arrangement when the intervention system defines the tool storage configuration and may be configured to permit fluid communication between the tool housing and the wellhead and/or the well valve arrangement when the intervention system defines the activated configuration.

The intervention system may comprise, may be operatively associated with, or may be coupled to, a valve arrangement. The valve arrangement may form part of the tool housing e.g. lubricator. The valve arrangement may be configured to prevent fluid communication between the tool housing and the wellbore, wellhead and/or the well valve arrangement (e.g. Christmas tree) when the intervention system defines the tool storage configuration. The valve arrangement may be configured to permit fluid communication between the tool housing and the wellhead and/or the well valve arrangement (e.g. Christmas tree) when the intervention system defines the activated configuration.

The valve arrangement may comprise a single valve. However, in particular embodiments, the valve arrangement may comprise a plurality of valves. In some embodiments, the valve arrangement may comprise two valves. In some embodiments, the valves arrangement may comprise three valves. The valves may be disposed in series. Beneficially, the provision of a valve arrangement comprising a plurality of valves in series provides at least a double barrier between the wellbore and the tool housing to ensure well integrity is maintained. Embodiments of the intervention system may thus permit a top valve of the well valve arrangement, e.g. the Christmas tree, to be maintained in an open position. This may permit the intervention system to interact with and/or have control over part or all of the well valve arrangement, such as a choke valve or the like, and/or control production from the well.

The valve arrangement may be configured to move between a closed configuration and an open configuration. The intervention system may define the tool storage configuration when the valve arrangement defines the closed configuration. The intervention system may define the activated configuration when the valve arrangement defines the open configuration.

The valve arrangement may be biased to the closed configuration. Beneficially, embodiments of the intervention system may be biased to the closed configuration to provide fail-safe operation. The controller may control operation of the valve arrangement. In some embodiments, the valve arrangement may comprise an independent control arrangement, such as an independent programmable logic controller.

As described above, the tool deployment arrangement is configured to deploy the intervention tool into the wellbore.

The intervention system may permit the intervention tool to be pumped into the wellbore under pressure.

The intervention system may permit the intervention tool to drop into the wellbore under the influence of its weight.

The tool deployment arrangement may comprise an automatic tool deployment arrangement.

The tool deployment arrangement may comprise a conveyance for transporting the intervention tool into and/or retrieving the intervention tool from the wellbore.

The conveyance may comprise a conductor line.

The conveyance may comprise a wireline.

The conveyance may comprise an E-line.

The conveyance may comprise a slickline.

The conveyance may comprise coiled tubing.

The intervention system may comprise a sealing system. The sealing system may be operatively associated with the conveyance. The sealing system may be disposed between the tool housing and the conveyance. In use, the sealing system may be configured to prevent leakage between the tool housing and the conveyance. Beneficially, the sealing system ensures that well control is maintained.

The tool deployment arrangement may comprise a winch. The winch may be configured to pay out and/or reel in the conveyance, e.g. the wireline.

In some embodiments, the winch may be disposed on the tool housing.

In other embodiments, the winch may be located on the ground, on a vehicle, a platform, a support arrangement of the intervention system or other location remote from the tool housing.

The tool deployment arrangement may comprise a pulley. In particular embodiments, the tool deployment arrangement may comprise a plurality of pulleys. The pulleys may be used to guide the conveyance between the winch and the tool housing to facilitate deployment and/or retrieval of the intervention tool into the wellbore.

The intervention system may comprise, may be operatively associated with, or may be provided in combination with, a drive arrangement. The drive arrangement may comprise a motor. The drive arrangement may comprise an electric motor. The drive arrangement may comprise a direct drive electric motor. The drive arrangement may comprise a worm drive.

The intervention system may be self-supporting, that is the intervention system may not require external support during operation, such as from an intervention vehicle, wireline truck or the like.

The intervention system may comprise a support arrangement.

The support arrangement may comprise a support mast.

The winch may be disposed on the support arrangement.

The intervention system may comprise a monitoring arrangement.

The monitoring arrangement may be configured to obtain information relating to a condition in the wellbore.

The monitoring arrangement may comprise a sensor arrangement.

The sensor arrangement may comprise a sensor. The sensor may comprise a plurality of sensors.

The sensor, or at least one of the sensors, may comprise a flow sensor.

The sensor, or at least one of the sensors, may comprise a pressure sensor.

The monitoring arrangement may be configured to obtain information relating to a condition of the intervention system.

The monitoring arrangement may comprise a visual monitoring system.

For example, the monitoring arrangement may comprise a camera system.

The camera system may comprise a camera for monitoring the condition of the conveyance. The camera may be disposed on the support arrangement.

The intervention system may comprise a communication arrangement. The communication arrangement may communicate the information obtained by the monitoring arrangement to a remote location. The communication arrangement may communicate with and transmit data from the monitoring arrangement. The communication arrangement may comprise a transmitter configured to transmit information wirelessly. Alternatively or additionally, the communication arrangement may comprise a transmitter configured to transmit information via wired communication, optical communication or other suitable means for transmission.

The remote location may comprise at least one of a vessel, a buoy, a platform or a rig. Alternatively, or in addition, the remote location may comprise an onshore facility, control room or the like.

The communication arrangement may comprise a satellite communication system. In use, information obtained by the monitoring arrangement may be transmitted to the remote location via satellite.

The communication arrangement may be configured to receive information instructing a change in the status of the intervention system. For example, the communication arrangement may be configured to receive information instructing that the system turn off, turn on and/or enter a stand-by or hibernation state.

The intervention system may comprise a receiver.

The intervention system may comprise a power supply for supplying to the intervention system.

In particular embodiments, the power supply may comprise one or more battery. Beneficially, the use of a battery permits the environmental impact of the intervention system to be reduced.

The power supply may comprise one or more rechargeable battery.

The intervention system may comprise an energy capture device arrangement.

The energy capture device arrangement may comprise one or a plurality of energy capture devices.

In particular embodiments, the energy capture device may comprise a solar energy capture device, such as a solar cell arrangement comprising one or more solar cell. In other embodiments, the energy capture device may comprise a wind energy capture device, such as a wind turbine.

The energy capture device arrangement may be configured to supply power to the intervention system.

The energy capture device arrangement may be configured to supply power to the power supply of the intervention system.

The energy capture device arrangement may recharge the power supply.

According to a second aspect, there is provided a well system comprising: the intervention system of the first aspect; and a wellbore.

The well system may comprise a wellhead valve arrangement. The wellhead valve arrangement may be disposed on a wellhead of the wellbore. In particular embodiments, the wellhead valve arrangement may comprise a Christmas tree.

The intervention system may be configured for coupling to the wellhead valve arrangement.

The tool housing may be configured for coupling to the wellhead valve arrangement. The tool housing may be disposed on top of the wellhead valve arrangement.

The intervention system may include the wellhead valve arrangement.

The well system may comprise a plurality of wellbores.

The well system may comprise a plurality of intervention systems. An intervention system may be provided for at least one of the plurality of wellbores. In particular embodiments, an intervention system may be provided for each of the plurality of wellbores.

According to a third aspect, there is provided a method comprising: providing an intervention system for a wellbore, the intervention system comprising: a tool housing configured to house an intervention tool for deployment into the wellbore; a tool deployment arrangement for deploying the intervention tool into the wellbore, wherein the intervention system is configurable between a tool storage configuration in which the tool housing is isolated from the wellbore and an activated configuration in which the tool housing communicates with the wellbore and permits deployment of the intervention tool by the tool deployment arrangement; and a controller configured to permit autonomous control of operation of the intervention system between the tool storage configuration and the activated configuration to facilitate deployment of the intervention tool into the wellbore; activating the intervention system from the tool storage configuration to the activated configuration; and operating the tool deployment arrangement to deploy the intervention tool into the wellbore.

The intervention system may be activated from the tool storage configuration to the activated configuration in response to a given activation event.

The activation event may take a number of different forms.

The activation event may relate to fluid flow. The fluid flow rate may comprise production flow rate for example.

In particular embodiments, the activation event may comprise a fluid flow rate dropping below a selected threshold. The intervention system may for example be activated in response to the production flow rate from the well dropping below a threshold in order to increase production from a well. Beneficially, such operations can be carried out autonomously and without the requirement to repeatedly transport personnel and equipment to/from site, reducing the costs and challenges associated with the intervention operation and environmental impact on the surrounding environment, wildlife and infrastructure.

The activation event may comprise a fluid flow rate reaching or exceeding a selected threshold.

The activation event may comprise a fluid flow rate decrease. The activation event may comprise a fluid flow rate dropping below a selected threshold.

The activation event may comprise a time event. For example, the intervention system may be configured to activate after a selected time has elapsed, or at a given time of day. Beneficially, embodiments of the intervention system may permit an intervention operation schedule to be implemented autonomously and without the requirement to repeatedly transport personnel and equipment to/from site, reducing the costs and challenges associated with the intervention operation and environmental impact on the surrounding environment and wildlife.

The activation event may comprise a pressure event.

The pressure event may comprise a differential pressure.

In particular embodiments, the activation event may comprise a pressure, such as differential pressure, reaching or exceeding a selected threshold.

In some embodiments, the activation event may comprise a pressure, such as differential pressure, dropping below a selected threshold.

The activation event may comprise a temperature event.

In particular embodiments, the activation event may comprise a temperature reaching or exceeding a selected threshold.

In some embodiments, the activation event may comprise a temperature dropping below a selected threshold.

The intervention system may be activated in response to a single activation event or a plurality of activation events, for example, but not exclusively, one or more of the activation events described above.

The method may comprise monitoring whether the activation event has occurred. The method may comprise using a monitoring arrangement of the intervention system to monitor whether the activation event has occurred.

Activating the intervention system from the tool storage configuration to the activated configuration may comprise operating a valve arrangement forming part of, operatively associated with, or coupled to, the intervention system between a closed configuration and an open configuration. In the closed configuration, the valve arrangement may prevent fluid communication between the tool housing and the wellbore. In the open configuration, the valve arrangement may permit fluid communication between the tool housing and the wellbore.

The valve arrangement may comprise a single valve. However, in particular embodiments, the valve arrangement may comprise a plurality of valves. The valves may be disposed in series.

The method may comprise operating a first valve of the plurality of valves between a closed configuration and an open configuration.

The method may comprise operating a second valve of the plurality of valves between a closed configuration and an open configuration.

The method may comprise monitoring the intervention system after the first valve has been moved to the open configuration before opening the second valve.

The method may comprise communicating the information obtained by the monitoring arrangement.

The method may comprise communicating the information relating to the intervention system using a communication arrangement. The method may comprise communicating the information relating to the intervention system to a remote location using the communication arrangement.

The method may comprise monitoring the intervention system after the second valve has been moved to the open configuration.

The method may comprise communicating the information obtained by the monitoring arrangement. The method may comprise communicating the information relating to the intervention system using the communication arrangement. The method may comprise communicating the information relating to the intervention system to the remote location using the communication arrangement.

The method may comprise monitoring the intervention system after the second valve has been moved to the open configuration before deploying the intervention tool.

The method may comprise communicating the information obtained by the monitoring arrangement. The method may comprise communicating the information relating to the intervention system using the communication arrangement. The method may comprise communicating the information relating to the intervention system to the remote location using the communication arrangement.

The method may comprise running the intervention tool into the wellbore.

The method may comprise performing an intervention operation in the wellbore.

The method may comprise retrieving the intervention tool from the wellbore.

The method may comprise retrieving the intervention tool into the tool housing.

The method may comprise operating the second valve between the open configuration and the closed configuration after the intervention tool has been retrieved from the wellbore.

The method may comprise monitoring the intervention system after the second valve has been moved to the closed configuration. The method may comprise communicating the information obtained by the monitoring arrangement. The method may comprise communicating the information relating to the intervention system using a communication arrangement. The method may comprise communicating the information relating to the intervention system to the remote location using the communication arrangement.

The method may comprise operating the first valve between the open configuration.

The method may comprise monitoring the intervention system after the first valve has been moved to the closed configuration.

The method may comprise venting well pressure from the tool housing.

According to a fourth aspect, there is provided a method comprising: deploying an intervention tool of a wellbore intervention system into a wellbore to perform a first intervention operation on the wellbore; retrieving the intervention tool from the wellbore; and producing from the wellbore, wherein the intervention system remains coupled to the wellbore during production.

The method may comprise deploying the intervention tool into the wellbore to perform a second intervention operation on the wellbore.

Beneficially, the intervention system may be stationed during construction and/or commissioning of the wellbore and may be retained in place for the operational life of the wellbore; obviating or at least mitigating the need to transport intervention equipment to site and thereby minimizing disruption to the local environment, wildlife and infrastructure.

Prior to deploying the intervention tool, the method may comprise activating the wellbore intervention system from a tool storage configuration in which the intervention system is isolated from the wellbore to an activated configuration in which the wellbore intervention system communicates with the wellbore and permits deployment of the intervention tool into the wellbore.

Prior to producing from the wellbore, the method may comprise reconfiguring the intervention system from the activated configuration to the tool storage configuration.

The method may comprise the step of coupling the intervention system to the wellbore. The intervention system may be coupled to a wellhead of the wellbore, either directly or as in particular embodiments via a well valve arrangement, such as a Christmas tree.

The intervention system may comprise a permanent installation. Alternatively, the intervention system may comprise a semi-permanent installation. For example, the intervention system may be retained in place for one or more phases of the operational life of the wellbore.

The intervention system may comprise an intervention system according to the first aspect.

According to another aspect, there is provided a processing system configured to implement one or more of the previous aspects.

The processing system may comprise at least one processor. The processing system may comprise and/or be configured to access at least one data store or memory. The data store or memory may comprise or be configured to receive operating instructions or a program specifying operations of the at least one processor. The at least one processor may be configured to process and implement the operating instructions or program.

The at least one data store may comprise, and/or comprise a reader, drive or other means configured to access, optical storage or disk such as a CD or DVD, flash drive, SD device, one or more memory chips such as DRAMs, a network attached drive (NAD), cloud storage, magnetic storage such as tape or magnetic disk or a hard-drive, and/or the like.

The processing system may comprise a network or interface module. The network or interface module may be connected or connectable to a network connection or data carrier, which may comprise a wired or wireless network connection or data carrier, such as a data cable, powerline data carrier, Wi-Fi, Bluetooth, Zigbee, internet connection or other similar connection. The network interface may comprise a router, modem, gateway and/or the like. The system or processing system may be configured to transmit or otherwise provide the audio signal via the network or interface module, for example over the internet, intranet, network or cloud.

The processing system may comprise a processing apparatus or a plurality of processing apparatus. Each processing apparatus may comprise at least a processor and optionally a memory or data store and/or a network or interface module. The plurality of processing apparatus may communicate via respective network or interface modules. The plurality of processing apparatus may form, comprise or be comprised in a distributed or server/client based processing system.

According to another aspect, there is provided a computer program product configured such that when processed by a suitable processing system configures the processing system to implement one or more of the previous aspects.

The computer program product may be provided on or comprised in a carrier medium. The carrier medium may be transient or non-transient. The carrier medium may be tangible or non-tangible. The carrier medium may comprise a signal such as an electromagnetic or electronic signal. The carrier medium may comprise a physical medium, such as a disk, a memory card, a memory, and/or the like.

According to another aspect, there is provided a carrier medium, the carrier medium comprising a signal, the signal when processed by a suitable processing system causes the processing system to implement one or more of the previous aspects.

It will be well understood by persons of ordinary skill in the art that whilst some embodiments may implement certain functionality by means of a computer program having computer-readable instructions that are executable to perform the method of the embodiments. The computer program functionality could be implemented in hardware (for example by means of a CPU or by one or more ASICs (application specific integrated circuits)) or by a mix of hardware and software.

Whilst particular pieces of apparatus have been described herein, in alternative embodiments, functionality of one or more of those pieces of apparatus can be provided by a single unit, processing resource or other component, or functionality provided by a single unit can be provided by two or more units or other components in combination. For example, one or more functions of the processing system may be performed by a single processing device, such as a personal computer or the like, or one or more or each function may be performed in a distributed manner by a plurality of processing devices, which may be locally connected or remotely distributed.

It should be understood that the features defined above or below may be utilized, either alone or in combination, with any other defined feature.

DETAILED DESCRIPTION OF THE INVENTION

Referring first toFIGS. 1 to 2of the accompanying drawings, there is shown an intervention system10, the intervention system10configured to perform an intervention operation in a wellbore12.

In the illustrated embodiment, the wellbore12is land-based having a wellhead valve arrangement in the form of a Christmas tree14disposed on a wellhead16.

The intervention system10is configured to deploy an intervention tool18(shown inFIG. 6) into the wellbore12and in the illustrated embodiment the intervention tool18comprises a paraffin wax removal tool for cleaning paraffin deposits from the wellbore12and associated infrastructure and equipment. However, it will be recognized that the intervention system10may be configurable to perform a number of different intervention operations using a suitable intervention tool.

As shown inFIGS. 1 and 2, the intervention system10comprises a tool housing in the form of a lubricator20. In the illustrated embodiment, the lubricator20comprises a stand of three connected heavy wall tubing sections, the interior of the lubricator20defining a tool storage compartment21(shown inFIG. 5) configured to house the intervention tool18.

As shown inFIGS. 1 and 2, the lubricator20is coupled to and disposed on top of the Christmas tree14. A valve arrangement22—which in the illustrated embodiment forms part of the lubricator20—permits selective communication of tools and fluid between the lubricator20and the Christmas tree14(or between the lubricator20and the wellbore12where no Christmas tree14is provided).

As shown inFIGS. 2 and 3, the valve arrangement22has an upper control valve24and a lower control valve26. In the illustrated embodiment, the valve arrangement22has an upper valve24and a lower valve26which can be controlled independently. The valve arrangement22provides a dual barrier between the lubricator20and the wellhead valve arrangement14, and permits an upper valve28of the Christmas tree14to be maintained in an open condition.

The intervention system10is configurable between a tool storage configuration in which the tool housing20is isolated from the wellbore12by the valve arrangement22and an activated configuration in which the valve arrangement22is open and the tool housing20communicates with the Christmas tree14and the wellbore12to permit deployment of the intervention tool18by a tool deployment arrangement30, as will be described below.

The tool deployment arrangement30is provided for deploying the intervention tool18into the wellbore12. The tool deployment arrangement30comprises a conveyance in the form of wireline32which is coupled to the intervention tool18and which extends through an upper end portion of the lubricator20via stuffing box34—in the illustrated embodiment a dual chamber stuffing box—to ensure pressure integrity of the tool housing20and monitors any fluid/gas wire bypass. An enlarged view of the stuffing box34is shown inFIGS. 4 and 5.

The tool deployment arrangement further comprises pulleys36,38for supporting the wireline32. In the illustrated embodiment shown inFIG. 1, pulley36is disposed on the tool housing20above the stuffing box34and pulley38is tied to wellhead16, although it will be recognized that the pulleys36,38may be disposed at other suitable locations.

A winch40is provided and is operatively coupled to a drive42which in the illustrated embodiment takes the form of a direct drive electric motor. In use, the drive42rotates the winch40in order to pay out the wireline32when it is desired to deploy the intervention tool18into the wellbore12and reel in the wireline32when it is desired to retrieve the intervention tool18from the wellbore12.

As shown inFIG. 2, in the illustrated embodiment a control desk44permits manual interface with the intervention system10by an onsite operative, where desired.

A power supply arrangement which in the illustrated embodiment takes the form of a battery unit46supplies power to the system10. Power conduit48supplies power from the battery unit46to the drive42and winch40. Power conduit50supplies power from the battery unit46to the valve arrangement22. Power to the power supply arrangement46in the illustrated embodiment is provided by an energy capture arrangement—represented generally by52—including an energy capture device which in the illustrated embodiment takes the form of a solar panel54.

The intervention system10further comprises a controller56in the form of a programmable logic controller (PLC) configured to permit autonomous control of operation of the intervention system10. It will be recognized that the controller56, or parts of the controller56, may be located at any suitable location, for example but not exclusively on the lubricator20or at the wellhead16.

A support arrangement in the form of support mast58supports the Christmas tree14and the lubricator20.

A monitoring arrangement is provided. In the illustrated embodiment, the monitoring arrangement comprises a flow sensor60and a pressure sensor62. However, it will be recognized that in other embodiments the intervention system10may comprise one or other of the flow sensor60and the pressure sensor62, or other sensors alone or in combination. The monitoring arrangement also comprises a visual monitoring system in the form of a camera64which in the illustrated embodiment is disposed on the support mast58. In use, the camera64facilitates remote visual monitoring of the tool deployment arrangement.

A communication arrangement—in the illustrated embodiment a transceiver66—is provided for communicating information to a remote location68either directly or as shown via satellite70. In use, the transceiver66communicates information obtained by the monitoring arrangement to the remote location68. In the illustrated embodiment, the transceiver66is configured for two-way communication; permitting commands to be sent to the intervention system10.

Operation of the intervention system10will now be described with reference toFIGS. 1 to 7of the accompanying drawings.

The intervention system10is initially disposed in the tool storage configuration with the intervention tool18disposed in the tool storage compartment21of the lubricator20. In this configuration, the upper and lower control valves24,26are configured in their closed configurations, thereby providing a dual barrier between the lubricator20and the Christmas tree14/wellbore12. As described above, the provision of the dual barrier beneficially permits the upper control valve28of the Christmas tree14to be maintained in an open configuration.

As illustrated inFIG. 7, on identifying that an activation event has occurred (e.g. the sensor detecting that the well flow rate has dropped below a threshold valve) the controller56will reconfigure the intervention system10from the well storage configuration to the activated configuration to permit deployment of the intervention tool18into the wellbore12by opening the lower and upper control valves24,26.

In the illustrated embodiment, the lower control valve26is opened first and then the upper control valve24. However, it will be recognized that in some instances the upper control valve26may be opened first or the valves may be opened simultaneously.

The monitoring arrangement monitors the intervention system to ensure that the control valves24,26have opened correctly and that pressure integrity has been maintained.

The controller56then activates the electric motor and winch of the tool deployment arrangement to pay out the wireline and deploy the intervention tool18into the wellbore12to perform the intervention operation.

In the illustrated embodiment, the intervention operation comprises running a paraffin wax removal tool into the wellbore12to remove paraffin wax deposits from the wellbore12and associated infrastructure and equipment.

On completion of the intervention operation, the controller56activates the electric motor and winch of the tool deployment arrangement to reel in the wireline and the coupled intervention tool18until the intervention tool18has been retrieved into the lubricator20.

The controller56then reconfigures the intervention system10from the activated configuration to the tool storage configuration by closing the upper and lower control valves24,26.

Well pressure may then be vented from the lubricator20.

It should be understood that embodiments described herein are merely exemplary and that various modifications may be made thereto without departing from the scope of the invention.

For example, and referring now toFIGS. 8 to 14of the accompanying drawings, there is shown an intervention system110according to a second embodiment. The intervention system110is similar to the intervention system10and like components of the system110to those of the system10are represented by like numerals incremented by 100.

As in the intervention system10, the intervention system110is configured to permit an intervention operation to be carried out on a wellbore112, the wellbore112also being land-based and having a wellhead valve arrangement in the form of a Christmas tree114disposed on wellhead116.

The intervention system110is configured to deploy an intervention tool118(shown inFIG. 13) into the wellbore112and in the illustrated embodiment the intervention tool118comprises a paraffin wax removal tool for cleaning paraffin deposits from the wellbore112and associated infrastructure and equipment. However, it will be recognized that the intervention system110may be configurable to perform a number of different intervention operations using a suitable intervention tool.

As in the intervention system10, the intervention system110comprises a tool housing in the form of a lubricator120. In the illustrated embodiment, the lubricator120comprises a stand of three connected heavy wall tubing sections, the interior of the lubricator120defining a tool storage compartment121(shown in Figure) configured to house the intervention tool118. As shown inFIG. 8, the lubricator120is coupled to and disposed on top of the Christmas tree114.

A valve arrangement122—which in the illustrated embodiment forms part of the lubricator120—permits selective communication of tools and fluid between the lubricator120and the Christmas tree114(or between the lubricator120and the wellbore112where no Christmas tree114is provided).

As shown inFIGS. 9 and 10, the valve arrangement122has an upper control valve124and a lower control valve126. In the illustrated embodiment, the valve arrangement122has an upper valve124and a lower valve126which can be controlled independently. The valve arrangement122provides a dual barrier between the lubricator120and the Christmas tree114, and permits an upper valve128of the Christmas tree114to be maintained in an open condition.

The intervention system110is configurable between a tool storage configuration in which the lubricator120is isolated from the wellbore112by the valve arrangement122and an activated configuration in which the valve arrangement122is open and the lubricator120communicates with the Christmas tree114and the wellbore112to permit deployment of the intervention tool118by a tool deployment arrangement130, as will be described below.

The tool deployment arrangement130is provided for deploying the intervention tool118into the wellbore112. The tool deployment arrangement130comprises a conveyance in the form of wireline132which is coupled to the intervention tool118and which extends through an upper end portion of the lubricator120via stuffing box134—in the illustrated embodiment a dual chamber stuffing box134—to ensure pressure integrity of the tool housing20and monitors any fluid/gas wire bypass. An enlarged view of the stuffing box134is shown inFIGS. 11 and 12.

In the intervention system110, the tool deployment arrangement130comprises a single pulley136which is disposed on the tool housing120above the stuffing box134.

A winch140is provided and is operatively coupled to a drive142which in the illustrated embodiment takes the form of a direct drive electric motor. In use, the drive142rotates the winch140in order to pay out the wireline132when it is desired to deploy the intervention tool118into the wellbore112and reel in the wireline132when it is desired to retrieve the intervention tool118from the wellbore112.

In the system110, it can be seen that the winch140and the drive142are disposed on the lubricator120. This provides a more compact system having a smaller footprint than the system10.

A power supply arrangement which in the illustrated embodiment takes the form of a battery unit146supplies power to the system110. Power conduit148supplies power from the battery unit146to the drive142and winch140. Power conduit150supplies power from the battery unit146to the valve arrangement122. Power to the power supply arrangement146in the illustrated embodiment is provided by an energy capture arrangement—represented generally by152—including an energy capture device which in the illustrated embodiment takes the form of a solar panel154.

The intervention system110further comprises a controller156in the form of a programmable logic controller (PLC) configured to permit autonomous control of operation of the intervention system110. It will be recognized that the controller156, or parts of the controller156, may be located at any suitable location, for example but not exclusively on the lubricator120or at the wellhead116.

A monitoring arrangement is provided. In the illustrated embodiment, the monitoring arrangement comprises a flow sensor160and a pressure sensor162. However, it will be recognized that in other embodiments the intervention system110may comprise one or other of the flow sensor160and the pressure sensor162, or other sensors alone or in combination.

A communication arrangement—in the illustrated embodiment a transceiver166—is provided for communicating information to a remote location168either directly or as shown via satellite170. In use, the transceiver166communicates information obtained by the monitoring arrangement to the remote location168. In the illustrated embodiment, the transceiver166is configured for two-way communication; permitting commands to be sent to the intervention system110.

Operation of the intervention system110will now be described with reference toFIGS. 8 to 14of the accompanying drawings.

The intervention system110is initially disposed in the tool storage configuration with the intervention tool118disposed in the tool storage compartment121of the lubricator120. In this configuration, the upper and lower control valves124,126are configured in their closed configurations, thereby providing a dual barrier between the lubricator120and the Christmas tree114/wellbore112. As described above, the provision of the dual barrier beneficially permits the upper control valve128of the Christmas tree114to be maintained in an open configuration.

As illustrated inFIG. 14, on identifying that an activation event has occurred (e.g. the sensor160detecting that the well flow rate has dropped below a threshold valve) the controller156will reconfigure the intervention system110from the well storage configuration to the activated configuration to permit deployment of the intervention tool118into the wellbore112by opening the lower and upper control valves124,126.

In the illustrated embodiment, the lower control valve126is opened first and then the upper control valve124. However, it will be recognized that in some instances the upper control valve126may be opened first or the valves may be opened simultaneously.

The monitoring arrangement monitors the intervention system to ensure that the control valves124,126have opened correctly and that pressure integrity has been maintained.

The controller156then activates the electric motor and winch140of the tool deployment arrangement130to pay out the wireline132and deploy the intervention tool118into the wellbore112to perform the intervention operation.

In the illustrated embodiment, the intervention operation comprises running a paraffin wax removal tool into the wellbore112to remove paraffin wax deposits from the wellbore112and associated infrastructure and equipment.

On completion of the intervention operation, the controller156activates the electric motor and winch140of the tool deployment arrangement130to reel in the wireline132and the coupled intervention tool118until the intervention tool118has been retrieved into the lubricator120.

The controller156then reconfigures the intervention system110from the activated configuration to the tool storage configuration by closing the upper and lower control valves124,126.

Well pressure may then be vented from the lubricator120.

As described above, the intervention systems110is configured to deploy and/or retrieve an intervention tool118into and/or from the wellbore112in order to perform an operation. An exemplary intervention tool118is shown inFIG. 15. It will be recognized that the intervention tool118may also be used as the intervention tool18in the intervention system shown inFIGS. 1 and 2.

As shown, the intervention tool118comprises a connector arrangement—which in the illustrated embodiment takes the form of a rope socket172and a thread connector174—for connecting the intervention tool118to the wireline132. The intervention tool118further comprises a mandrel176—in the illustrated embodiment a jar rod—and an end cap178. A cutter, shown generally at180, is disposed on the mandrel176and is coupled to the mandrel176so as to be axially moveable relative to the mandrel176. In the illustrated embodiment, the cutter180comprises one or more wire cutter elements182. In use, movement of the cutter180relative to the mandrel176acts to remove paraffin deposits or other solids or residues from the wellbore112.

Beneficially, embodiments of the intervention system permit wellbore integrity to be managed and production maintained safely and efficiently while at the same time permitting intervention operations, such as paraffin wax cleaning operations for example, to be carried out autonomously. Moreover, embodiments of the intervention system may reduce the environmental impact on the surrounding environment, for example reducing the requirement for large and heavy vehicles; reduce carbon emissions, and noise. Vehicle fleet management and personnel costs may also be reduced.

A well system1010according to an embodiment is shown inFIG. 16of the accompanying drawings. As shown, the well system1000comprises a plurality of wellbores1012, a first intervention system1010operatively associated with a first of the wellbores1012and a second intervention system1100operatively associated with a second of the wellbores1012. The intervention systems1010,1110may be of the same configuration or different configurations. For example, in the illustrated embodiment, the first intervention system1010corresponds to the intervention system10while the second intervention system1110corresponds to the intervention system110.

In the illustrated embodiment, the intervention systems1010,1110each have their own power supply in the form of battery units1046,1146, controller1056,1156and energy capture arrangement1052,1152. However, it will recognized that the intervention systems1010,1110—in particular but not exclusively those relating to wellbores from the same field—may be coupled to a common power supply, energy capture arrangement and/or controller.

Similarly, the intervention systems1010,1110each have their own communication arrangement1066,1166for communicating information to a remote location1068either directly or as shown via satellite1070.

Beneficially, embodiments of the well system1000permit wellbore integrity to be managed and production maintained safely and efficiently while at the same time permitting intervention operations, such as paraffin wax cleaning operations for example, to be carried out autonomously. Moreover, embodiments of the well system1000may reduce the environmental impact on the surrounding environment, for example reducing the requirement for large and heavy vehicles; reduce carbon emissions, and noise. Vehicle fleet management and personnel costs may also be reduced.

As described above, it should be understood that embodiments described herein are merely exemplary and that various modifications may be made thereto without departing from the scope of the invention.

For example, while in the described embodiments the systems and methods are directed to the removal of paraffin wax from a wellbore and associated infrastructure and equipment, it will be understood that the systems and methods may be used to perform any suitable intervention operation, including not exclusively well logging operations.