GB2603746A

GB2603746A - Well apparatus and associated methods

Info

Publication number: GB2603746A
Application number: GB2100232.4A
Authority: GB
Inventors: Lees Iain
Original assignee: Resolute Energy Solutions Ltd
Current assignee: Resolute Energy Solutions Ltd
Priority date: 2021-01-08
Filing date: 2021-01-08
Publication date: 2022-08-17
Anticipated expiration: 2041-01-08
Also published as: GB2603746B; GB202100232D0

Abstract

A method of applying a swellable coating on an apparatus deployed in a bore comprises applying the swellable coating. An apparatus coated in the swellable coating is also claimed and can be a valve, a packer, an intervention tool, a tubular, a casing, a bridge, a patch, a clamp, a control line, a wireline, a coiled tubing or a screwthread. The swellable coating may be particulate and may be applied using an adhesive.

Description

WELL APPARATUS AND ASSOCIATED METHODS

TECHNICAL FIELD

This disclosure concerns wells, boreholes, well apparatus and associated methods. For example, the disclosure concerns well apparatus and associated methods for sealing in a well. In particular, but not exclusively, examples of the disclosure concern methods of treating or preparing apparatus for use downhole.

BACKGROUND

Drilled bores, such as for accessing subterranean hydrocarbon reserves, are often cased or lined to assist in the transport of fluids through the bores. Viable bores are typically lined or cased with tubular steel members, such as casing and/or liners, which is often cemented in place.

Various operations are performed in the bore, such as for completion of the bore, ready for production. Similarly, once production has commenced, other operations can be performed in the bore. For example, operations may be undertaken to adapt production, such as to accommodate variations in production fluids or circumstances. Likewise, remedial operations may be undertaken, such as to accommodate changes in production fluids or downhole equipment. For example, where production occurs, remedial action may be taken to mitigate flowing water in the production fluid to surface. Accordingly, intervention apparatus may be deployed downhole for such operations. In some bores, downhole equipment may require revision or replacement after a period of time downhole.

To enable many intervention operations, the bore may be plugged, especially downhole of the location of the intervention operation. Often a double plug is employed to mitigate a failure of a single plug. Particularly after production from the bore has been completed, or where the bore has become no longer viable, the bore may be plugged and abandoned. The plugging and abandonment of bores is generally performed to mitigate against the unintended transport of fluid through the bore. For example, where the bore has accessed a pressurised subterranean hydrocarbon reserve, the redundant post-production bore is plugged and abandoned to prevent an undesired release of oil or gas into the surrounding environment, such as an adjacent seabed.

The subject matter of at least some examples of the present disclosure may be directed to overcoming, or at least reducing the effects of, one or more of the problems of the prior art, such as may be described above.

SUMMARY

According to a first aspect there is provided a method of applying a swellable. The method may comprise sealing. The method may comprise sealing in a bore. The method may comprise applying a swellable to the bore. The method may comprise applying the swellable to an apparatus for deployment in the bore. The apparatus may comprise an oil/gas apparatus, such as a downhole apparatus (e.g. tool or the like). The method may comprise applying the swellable as a coating. The coating may comprise a continuous coating. The swellable may be comprised as a constituent in a mixture. The swellable may be comprised as a particulate in the coating.

The coating may be applied by deposition. The coating may be applied by spraying. The coating may be applied by vapour deposition, such as physical vapour deposition (PVD). The method of applying the coating may comprise sputtering and/or evaporation. The coating may be applied by pouring. The coating may be applied by moulding, such as injection-moulding, extrusion moulding, compression moulding or the like.

The method may comprise applying at least a portion of the coating in fluid form. The method may comprise applying at least a portion of the coating as a liquid. The method may comprise applying the coating as a fluid and hardening or setting the fluid to or on the apparatus. The method may comprise the application of a thermoform, such as a thermoform polymer swellable and/or carrier fluid.

In at least some examples, the method may comprise entraining the swellable in a carrier fluid for application to the apparatus. In at least some examples, the method may comprise applying the swellable as a particulate within a mixture. The method may comprise providing the swellable as a particulate in the mixture prior to application to the apparatus. For example, the method may comprise mixing the swellable particulate with the fluid, such as the carrier fluid, prior to application to the apparatus.

The fluid may comprise an adhesive. In at least some examples, the fluid may comprise a setting fluid. The fluid may be configured in dependence on the apparatus, such as the substrate properties of the apparatus (e.g. chemical material properties and/or surface roughness or the like). The fluid may be selected to provide adherence to the apparatus.

The fluid may be selected to provide adherence of the swellable to the apparatus.

The method may comprise applying the swellable and/or carrier fluid in a first state, such as a liquid and/or gas state; and transforming the swellable and/or carrier fluid to a second state, such as solid. The method may comprise reconfiguring the state of the swellable and/or carrier fluid before and/or during and/or after application to the apparatus. For example, the method may comprise heating and pressurising the swellable and carrier fluid as a mixture prior to application. Additionally, the method may comprise reconfiguring the coating after application to the apparatus. For example, the method may comprise treating or curing the coating; or at least a constituent thereof. The reconfiguration may be active, such as a powered, active heating (e.g. baking or curing the coating). Additionally, or alternatively, the reconfiguration may be passive, such as attributable to an environmental condition or factor (e.g. cooling to or at an atmospheric temperature). The carrier fluid may form or remain as part of the swellable coating, such as where the carrier fluid is set, cured or hardened. In other methods, the carrier fluid may form a substrate for the swellable coating, effectively forming a sub-coating beneath the swellable. Additionally, or alternatively, the carrier fluid, or a component/s thereof, may be removed or diminished at or after application of the swellable, For example, at least a component of the carrier fluid and/or swellable mixture may be removed or diluted in quantity (e.g. by evaporation, mechanically, melting, heating or the like).

The method may comprise providing a layer on top of the swellable coating. In at least some examples, the layer may comprise a protective layer, such as to protect the swellable coating from the environment. The layer may comprise a sacrificial layer. The layer may comprise a temporary layer. The method may comprise protecting the swellable coating, such as in transit to a well site and/or into the wellbore at the well site.

The method may comprise providing the swellable as entrained and enclosed particles within the coating. Accordingly, the swellable particles may be protected from the immediate environment when applied in the coating, at least initially when applied. The method may comprise providing an external layer, such as on top of or external to the swellable particles. For example, in at least some methods, an additional layer or coating may be applied on top of at least a portion of the swellable coating. The additional layer or coating may comprise a temporary layer or coating, such as for transit and/or time delay prior to possible swelling of the swellable. The additional layer or coating may be sacrificial. The additional layer or coating may comprise a similar material or property of at least a component of the swellable coating or layer. For example, the additional layer or coating may comprise a same fluid as the carrier or adhesive fluid for the swellable. Alternatively, the additional layer or coating may comprise a different material and/or property. For example, the additional layer or coating may comprise a removable layer or coating, such as a soft and/or soluble layer or coating. The method may comprise coating the particulate swellable with the additional layer or coating. For example, the method may comprise coating the swellable particles with the additional layer or coating to inhibit or delay swelling. The additional layer or coating may be configured to allow the application of the swellable without activation of the swellable. The additional layer or coating may assist in the application or deployment of the apparatus. For example, where the swellable is an oil-swellable, the swellable particles may be coated so as to prevent initial swelling such as to allow the apparatus to be run-in in the presence in the presence of an oil-based fluid. The additional layer or coating may enable a delay or timing management of the activation of the swellable. The additional layer or coating may be an adaptable coating, such as to be mechanically and/or thermally and/or chemically adapted, such as by or during the application or apparatus deployment process -or a subsequent process (such as by flushing with an agent to act on the additional layer or coating). The additional layer or coating may be adaptable so as to be at least partially removed from the swellable particles and/or so as to be at least partially activatable so as to set or mechanically join or bond with the coating portion/s of other coated swellable particles and/or the swellable. In at least some examples, the additional layer or coating may be adaptable so as to set to form a matrix to hold the swellable particles in place (e.g. prior to and/or subsequent to swelling of the swellable particles).

The method may comprise treating the coating/s, such as the swellable coating, during and/or after application. The method may comprise adapting, such as machining, the coating/s during and/or after application. For example, the method may comprise machining the swellable coating, particularly when the swellable coating is solid (e.g. after hardening). The method mayc comprise machining the coating to a particular size or dimension, such as to a predefined tolerance. In at least some examples, the machining may comprise machining the coating to a target thickness and/or target dimension, such as a target outer diameter. In at least some methods, the application process of applying the coating may comprise an application process with an undesired tolerance range, such that it may be desirable to apply an excess of coating to ensure sufficient coverage and then achieve a target tolerance or dimension by subtraction from the coating (e.g. by machining).The method may comprise machining the swellable coating prior to application of an additional layer/s or coating/s on top of the swellable coating or layer. Optionally, the method may comprise machining the additional layer/s or coating/s, such as after application on top of the swellable. The method may comprise machining the swellable during application, such as prior to a treatment, curing, setting or finishing step of th application process.

The method may comprise exposing at least a portion of the/each swellable particle. In at least some examples, the method may comprise ensuring that at least some of the/each swellable particle/s has an external surface exposed. For example, portion/s of the swellable particles may define at least a portion of an exterior surface of the coating.

The exterior surface of the coating may be that/those not adjacent or adhering to the apparatus. As such the exterior surface/s of the coating may form at least a portion/s of the exterior surface/s of the apparatus, once coated.

The method may comprise applying the swellable as an exterior coating on the apparatus. Additionally, or alternatively, the method may comprise providing the swellable as an interior coating on the apparatus. In at least some examples, the method may comprise providing the swellable as an intermediate coating in the apparatus. For example, the method may comprise applying the swellable as a coating a first portion of an apparatus, such as a first component. The method may further comprise post-coating construction of the apparatus, such as an assembly of portions or components of the apparatus. For example, the method may comprise coating at least one surface of a first component and then assembling that first component in, on or to a second component. In at least some examples, the method may comprise coating a plurality of components of the apparatus. The method may comprise coating the plurality of components separately and/or individually, such as prior to assembly. Additionally, or alternatively, the method may comprise coating the plurality of components in an assembled configuration.

The method may comprise applying the swellable so as to (substantially) fill a recess.

The recess may comprise a local depression, cavity, blind opening or the like in a component. The recess may comprise a gap. For example, the method may comprise filling a gap, such as in a component, or between two or more components. The method may comprise filling a seal recess with the swellable so as to provide at least a portion of a seal as a swellable seal, such as one or more of filling an o-ring groove; or a recess for a seal stack with the swellable.

In at least some examples, the method may comprise providing the swellable as a backup, redundant or emergency coating. For example, the swellable coating may be provided in addition to another seal on or of the apparatus. The other seal may comprise a swellable seal and/or may comprise a non-swellable seal, such as a resilient seal (e.g. an 0-ring, gasket, or the like).

The apparatus may comprise one or more of: a valve; a packer; an intervention tool; a plug; a tubular; a casing; a bridge; a sleeve; a patch; a clamp; a control line; a wireline apparatus; a coiled-tubing apparatus. In at least some examples, the method comprises applying the coating to at least a portion of a screwthread. The swellable coating may be applied to at least one of the components of the screwthread (e.g. male and/or female) prior to mating of the screwthreads. Additionally, or alternatively, the swellable coating may be applied during and/or after the mating of the screwthreads.

The method may comprise providing the swellable coating as a layer. The layer may be an outermost layer, such as an outermost layer of a surface of the apparatus. The surface of the apparatus may be an internal apparatus surface. For example, the method may comprise applying the swellable coating to an inner surface of a tubular.

The method may comprise the provision of the swellable coating for non-use or non-activation in normal use of the apparatus. The swellable coating may be provided as a remedial, redundant or back-up coating. For example, the coating may be provided on the apparatus for use in an unintended, undesired or emergency situation, such as where a portion or component of the apparatus, or other downhole apparatus, fails. In at least some examples, the swellable coating may be provided as a redundant or back-up seal, such as for use in an event of a failure of another seal.

The swellable may comprise a polymer. The swellable may comprise a polymer-based swellable. The swellable may comprise a swellable polymer. Applying the swellable may comprise applying the swellable in a flow onto the apparatus. In at least some examples the flow may comprise a carrier for the swellable, such as a carrier fluid or liquid. The swellable may be fluidized, at least for application to the apparatus. The swellable may be fluid-borne, at least for application to the apparatus. The method may comprise applying the swellable at an uphole location, such as at a wellhead and/or surface location. In at least some examples, the method may comprise applying the swellable to the apparatus off-site, such as remote from the wellhead (e.g. a in a factory or workshop premises or the like).

The method may comprise applying the swellable as a plurality of elements. The method may comprise applying the swellable to the apparatus in a non-annular form. The method may comprise applying the swellable to the apparatus in an indefinite form. The swellable may comprise an indefinite form prior to application. The indefinite form may comprise a fluid form. The indefinite form may comprise a pourable form. The swellable may comprise a non-preformed swellable prior to application. The method may comprise applying the swellable to the apparatus in particulate form. The particulate form may comprise one or more of: granules, pellets, powder/s. The particulate form may comprise an indeterminate or non-defined arrangement or relationship between the particles of the swellable, at least prior to application. The method may comprise not pre-forming the swellable prior to application to the apparatus. The method may comprise entraining the swellable, such as for fluidized application.

The method may comprise applying the swellable so as to form an annular coating. The annular coating may define one or more of: a ring; a disc; a circle; an o-ring; a gasket; a sleeve-seal.

The method may comprise applying the swellable in a mixture. The method may comprise applying the swellable in a carrier, such as a carrier fluid. The fluid may comprise a solvent. In at least some examples, the carrier may comprise an inert fluid. The carrier may comprise an activating fluid. Additionally, or alternatively, the carrier may comprise a spacer or matrix material. Additionally, or alternatively, the carrier may comprise a settable fluid. Additionally, or alternatively, the carrier may comprise a hardening material. The hardening material may comprise a settable polymer. In at least some examples, the method may comprise applying the swellable as part of a singular coating operation. Applying the swellable as part of the coating may comprise applying the carrier fluid and the swellable simultaneously, such as a carrier/swellable mixture. In other examples, the swellable may be applied non-simultaneously, such as sequentially or alternately with the carrier fluid. For example, where the carrier fluid comprises an adhesive, the adhesive may be applied discretely prior to the application of the swellable. The carrier fluid may be applied in fluid form; then the particulate swellable applied to the carrier fluid (wherein the carrier fluid has formed a pre-coating on the apparatus at the location/s desired to be coated with the swellable). The particulate may be applied as a powder, such as sprayed, dipped and/or otherwise deposited onto the adhesive substrate.

B

The swellable may be selected from one or more of: a synthetic swellable; a polymer swellable; a polymer-based swellable; a water-swellable swellable; an oil-swellable; a hydrocarbon oil swellable; a swellable acfivatable by a non-water-based fluid; a swellable activatable by a non-oil-based fluid; an elastomer; a rubber. In at least some examples, the swellable may comprise all of said aforementioned properties or features. In such examples, the swellable may comprise an oil-and water-swellable synthetic elastomeric rubber polymer. In at least some other examples, the swellable may comprise only a limited number of said aforementioned properties or features. For example, in such other examples, the swellable may comprise a water-swellable synthetic elastomeric rubber polymer that is not oil-swellable. In yet other examples, the swellable may comprise an oil-swellable synthetic elastomeric rubber polymer. In at least some examples, the swellable may comprise a swellable in a matrix for application, such as a swellable polymer gel composition for application.

The method may comprise applying the swellable such as to form a seal to prevent a flow of fluid/s longitudinally along the apparatus and/or a bore within which the apparatus is to be located. For example, the method may comprise applying the swellable as an annular coating around or at an interior and/or exterior surface of the apparatus so as to enable or assist a sealing engagement with or by the apparatus. The method may comprise applying the swellable such as to form a swellable seal along a longitudinal section or length of the apparatus such as with a continuous or discontinuous axial length of the swellable coating axially along at least a portion of the apparatus. In at least some examples, the swellable coating may comprise a length of at least 1 metre, or more than 2, 3 or 5 metres. In at least some examples, the swellable coating may comprise a length of at least 50 centimetres. In at least some examples, the swellable coating may comprise an axial length of at least 100 centimetres. Preventing a flow of fluid/s along the apparatus may comprise preventing a flow of fluids out of and/or into a bore or annulus or other passage of the apparatus, such as axially out of, into and/or axially along a central or annular bore of the apparatus.

In at least some examples, the seal may prevent or assist in preventing the flow of fluids laterally into and/or out of and/or along the apparatus.

The method may comprise applying the swellable as a layer or zone within or on the apparatus. The layer or zone may comprise an axial layer or zone. The method may comprise applying a plurality of layers or zones of swellable. The plurality of layers or zones of swellable may comprise swellables of different properties. For example, a first layer or zone may comprise a first type of swellable; and a second layer or zone may comprise a second type of swellable, the second type of swellable being different from the first type of swellable. Additionally, or alternatively, in at least some example methods, a plurality of layers or zones of the same type of swellable may be applied. For example, distinct layers or zones of swellable may be applied, such as sequentially. The plurality of layers or zones of swellable may be separated by an intermediate layer/s or zone/s, such as separated by spacers, uncoated portions of the apparatus or other types of material (e.g. other types of sealing material, such as another type of swellable). The method may comprise sandwiching one or more layers or zones. For example, the to method may comprise applying alternate layers of swellable and carrier fluid; and/or of two different types of swellable. Each layer or zone may comprise a particular axial length and/or coating thickness.

The swellable may comprise an indefinite or undefined shape prior to application, such as prior to insertion into the apparatus. In at least some examples, the swellable comprises an injectable or pumpable form prior to application, such as a swellable comprised of multiple discrete particles, elements, granules, pellets and/or powder.

In at least some examples, the method may comprise a further step of sealing, such as with the swellable coating on the apparatus located downhole. The sealing may be for one or more of; temporary sealing; permanent sealing; remediation sealing; emergency sealing; reactive sealing; preventative sealing; abandonment.

The method may comprise actively swelling the swellable such as to form the seal. The method may comprise actively swelling the swellable to seal with an activating fluid. The method may comprise actively swelling the swellable by exposing the swellable to the activating fluid. The method may comprise actively swelling the swellable by introducing or injecting the activating fluid. The method may comprise actively swelling the swellable by opening a flowpath for the activating fluid. The method may comprise applying the activating fluid from uphole, such as from surface or a wellhead. Additionally or alternatively, the method may comprise applying the activating fluid from downhole, such as from the reservoir or adjacent formation. The method may comprise applying the activating fluid longitudinally to the swellable, such as from topside or an uphole end of the swellable section.

The method may comprise curing the swellable. The method may comprise swelling the swellable pre-curing and/or post-curing. In at least some examples, the method may comprise providing a swellable coating that is swellable post-curing such as to be swellable to be self-sealing (e.g. to fill cracks, microannuli, or voids after complete curing). The method may comprise the provision of swellable particles sized and proportioned so as to contact and/or pressurise an adjacent space, such as a gap in, at or adjacent the apparatus. For example, the coating may be configured to swell to seal or at least assist in sealing cracks and microannuli or other potential flowpaths for fluid, such as hydrocarbon fluid. The method may comprise the provision of particles with at least a portion with a radius respectively less than 10 mm; less than 5mm; less than 2 mm; less than 1mm; less than 0.1mm; less than 0.01mm. In at least some example to methods, the swellable may comprise a diameter less respectively less than 10 mm; less than 5mm; less than 2 mm; less than 1mm; less than 0.1mm; less than 0.01mm (or doubles thereof). The diameter may comprise a nominal diameter; or a maximum diameter in different methods of applying the swellable coating. The method may comprise providing a range of sizes of swellable.

The method may comprise providing a defined thickness of coating. The thickness of the coating may comprise a sub-millimetre coating, such as of a thickness of 100 microns, 200 microns, 500 microns, or more. Alternatively the coating may comprise a thickness of 1 mm or more, such as of 1.5mm; 2mm; 5mm; 10mm or more. The coating may be provided at a first thickness and configured to swell to a second thickness, the second thickness being greater than the first thickness. The second thickness may be a factor greater than the first thickness. For example, the swellable coating may be configured to increase thickness by swelling of 100% or more. The second thickness may be 50% greater than the first thickness; 150% greater; 200% greater; or more. For example, where a swellable coating of 2mm is provided on the apparatus; the coating may swell to a second thickness of 4mm or more. It will be appreciated that in some methods the coating may be constrained such that the swelling of the coating may not be purely translated to a dimensional or geometric expansion, but may additionally or alternatively translate to an exertion of pressure and/or force. For example, the swellable coating may press against a surface, or surface, on swelling; or press more on swelling.

The coating may be configured to provide and/or compensate for a fit and/or clearance. For example, the coating may be configured for one or more of: a close fit; an interference fit; a clearance fit. Accordingly, the method may comprise applying the coating to at least a portion of the apparatus that is to be assembled or located in such a fit. The fit may be of the assembled apparatus at surface (e.g. the coating may be in the fit gap at surface). Additionally, or alternatively, the fit may be of the apparatus when located downhole. In at least some examples, the method comprises coating at least a portion of the apparatus where the apparatus is intended to be landed or mated downhole, such as with other apparatus run-in, or to be run-in, and/or other apparatus already present downhole In at least some methods, the coating is provided at a first thickness whereby a clearance fit is enabled. The coating may be configured to swell so as to compensate or overcome the clearance fit. For example, the clearance fit may enable or assist an assembly or mating; whereafter the swelling may fill the clearance such that there is no gap between the assembled or mated components. The assembly or mating may take place at surface and/or downhole.

In at least some examples, the method may comprise providing an irreversibly swellable coating. For example, the swellable may expand upon exposure to a particular chemical or material, or genus or type thereof. In other examples, the method may comprise providing a reversibly swellable coating. The swellable may be reversible by applying an antidote product, such as by applying an antidote fluid. The antidote fluid product may comprise an antidote chemical, such as a particular acid or agent that chemically and/or thermally and/or mechanically damages the swellable and/or a matrix, adhesive, filler or other substance that may hold the swellable in position.

The method may comprise measuring the coating. The method may comprise measuring one or more coating parameters, such as during and/or after application of the swellable and/or after activation of the swellable. The method may comprise validating the coating. In at least some example methods, the coating may be tested, such as with a pressure test to evaluate coating and/or sealing integrity.

In at least some examples, the method may comprise the repair of an apparatus. The method may comprise repairing a damaged or worn apparatus. The method may comprise repairing and/or supplementing an existing coating or component of the apparatus. The method may comprise applying the coating to the damaged or worn portion.

The method may comprise retro-fitting. For example, the method may comprise applying the coating to a used, pre-existing or aged apparatus.

The method may comprise the use, reuse or recycling of components or materials. For example, the method may comprise the use, reuse or recycling of swellable components or materials. The method may comprise using leftover production materials, such as from the production processes for: swellable packers; gaskets or other pre-formed swellable products. The method may comprise the reuse of excess or waste material from the production of other prefabricated swellable product/s. The method may comprise the pre-processing or pre-treatment of such material prior to application to the apparatus. For example, the method may comprise the refinement or granulisation of the material, such as to provide particles, pellets or granules of a predetermined size and/or shape for application to the apparatus. The method may comprise conditioning the particulate swellable. The method may comprise one or more of: categorisation; separation; adaption of the swellable particulates to provide swellable particulates of a particular size/s and or shape/s.

In at least some examples, the coating and/or swellable may comprise a resistance to one or more of: chemicals; hydrogen sulphide; acid; high temperature hydrocarbons; high pressure hydrocarbons; temperatures up to 500F, 650F, respectively; pressures up to 18,000psi; temperatures below freezing, such as down to -60C.

The method may comprise a selection of an optimum swellable characteristic/s. The optimum swellable characteristic/s may comprise one or more of: swellable particle size; swellable chemical composition; swellable particle shape; swellable activation fluid (e.g. oil-based and/or water-based); chemical resistivity; thermal resistivity or combinations hereof, such as mixture/s of particle sizes and/or particle shapes. The method may comprise performing the selection with the aid of calculation and/or simulation; such as a simulation based upon a model of one or more bore characteristics.

The method may comprise providing the swellable coating to obstruct a throughbore, such as a central throughbore. Additionally, or alternatively, the method may comprise providing the swellable coating to the apparatus so as to obstruct an annulus, such as an annular passage between the apparatus and a casing or other tubular; or the apparatus and the borewall or another apparatus, such as longitudinally overlapping (e.g. concentric) apparatus, or axially abutting apparatus.

The method may comprise providing a swellable at a downhole control line. For example the apparatus to be or being coated may comprise at least a portion of control line. The control line may comprise a cable and/or conduit. The conduit may comprise a fluid passage, such as for a hydraulic line or an injection line. The control line may comprise a plurality of lines, such as a plurality of conduit/s and/or wire/s or cable/s. The control line may comprise a bumper line. The method may comprise using the swellable to provide a permanent or temporary sheath or protection around a cable/control line. The method may comprise providing the sheath prior to running-in the control line. For example, the control line may be provided with the swellable coating prior to installation of the control line. The method may comprise preventing a potential leak path at or along the control line. The method may comprise providing a seal around a downhole control line/s. In at least some examples, the provision of the swellable may mitigate against the existence or development of a potential leakpath, such as where a more conventional to cable or control line coating, such as with a non-swellable polymer, may otherwise leave a potential leak path. In at least some examples, the method may provide an alternative to the removal of at least sections of control line during abandonment. For example, the provision of the swellable may negate a requirement to remove a minimum length of control line from a well to be abandoned, potentially saving considerable time for removing the control line, and saving associated expense. For example, the method may facilitate the abandonment of a well comprising all or substantially comprising all of the casing and/or liner and/or control line and/or production tubing. In at least some examples, the method may comprise an abandonment operation. The operation may not require or comprise removing any of: casing; and/or liner; and/or control line; and/or production tubing. The method may comprise leaving the casing; liner and/or control line downhole. The method may comprise not pulling a length of control-line, and optionally associated casing or liner, to provide a control-line free length of bore for abandonment.

In at least some examples, the swellable coating may comprise a length at least as long as a corresponding length of control line that may otherwise be required to be removed for bore abandonment. Following application, the swellable coating may comprise an axial length of 150 metres or more.

According to a further aspect there is provided an apparatus comprising the coating. The coating may be as described in any other aspect, embodiment, example or claim of this

disclosure.

According to a further aspect there is provided a coating. The coating may comprise the coating as described in any other aspect, embodiment, example or claim of this disclosure.

According to a further aspect there is provided a swellable for sealing in a bore. The swellable may be that as described in any other aspect, embodiment, example or claim of this disclosure. The swellable may be configured for application to the apparatus. In at least some examples, the swellable may comprise a particulate form, such as one or more of: pellet; granule; and/or powder.

According to a further aspect there is provided a method of manufacturing the device or apparatus of any other aspect, example, embodiment or claim. The method may comprise additive or 3D printing. The method may comprise transferring manufacturing instructions, such as to or from a computer (e.g. vie internet, e-mail, file transfer, web or the like).

The invention includes one or more corresponding aspects, embodiments or features in isolation or in various combinations whether or not specifically stated (including claimed) in that combination or in isolation. For example, it will readily be appreciated that features recited as optional with respect to the first aspect may be additionally applicable with respect to the other aspects without the need to explicitly and unnecessarily list those various combinations and permutations here (e.g. the device of one aspect may comprise features of any other aspect). Optional features as recited in respect of a method may be additionally applicable to an apparatus or device; and vice versa.

In addition, corresponding means for performing one or more of the discussed functions are also within the present disclosure.

It will be appreciated that one or more embodiments/aspects may be useful in at least partially sealing.

The above summary is intended to be merely exemplary and non-limiting.

Various respective aspects and features of the present disclosure are defined in the appended claims.

It may be an aim of certain embodiments of the present disclosure to solve, mitigate or obviate, at least partly, at least one of the problems and/or disadvantages, such as described herein or elsewhere.

BRIEF DESCRIPTION OF THE DRAWINGS

to These and other aspects of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an example flow chart of an example method; Figure 2 is a schematic cross-sectional side view of a portion of an apparatus according to an example; Figure 3 is a schematic cross-sectional side view of a portion of an apparatus according

to another example;

Figure 4 is a detail schematic view of a portion of an apparatus according to another example Figure 5 is a schematic sectional side view of a portion of a well in accordance with an 20 example; Figure 5a shows a detail of the well of Figure 5 in a first configuration; Figure 5b shows the detail of the well of Figure 5 in a second configuration; and Figure 6 is a schematic cross-sectional side view of a portion of an apparatus according to another example.

DETAILED DESCRIPTION

Referring first to Figure 1, there is shown an example flow chart of a method 2 according to the present disclosure. The method 2 comprises a first step 4 of applying a swellable coating; and a second step 6 of swelling the swellable. In at least some examples, the method 2 includes a further step 8 of providing a seal. The seal may be provided by the swelling of the swellable. For example, the swellable coating may swell to close a gap or a space, so as to create a seal. Additionally, or alternatively, the seal may be provided separately. For example, the swellable coating may be provided as an enhancement or a back-up for another seal.

As described in greater detail below, the swellable coating may be applied to, or deposited on, an apparatus. The apparatus may comprise one or more of: a sleeve, patch, tubular, tubular member or cylindrical body. The apparatus may be a liner or casing string. The swellable coating may be applied to a tool. The swellable coating may be applied to an apparatus prior to being run downhole into an oil/gas wellbore. The swellable coating may be in an inactive or non-activated state when applied to an apparatus.

The swellable coating may be applied to an apparatus by spraying. Alternatively, the swellable coating may be applied by dipping an apparatus, or a portion thereof, into the swellable coating. The swellable coating may be applied by injecting into a portion or region of an apparatus, e.g. between cooperating or engaging threads. The swellable coating may be applied to an apparatus by a combination of spraying and dipping.

The swellable coating may be applied so as to form a substantially uniform layer. Alternatively, the swellable coating may be applied so as to have regions or zones having different thicknesses. The swellable coating may be applied along the entire length of an apparatus, e.g. a cylindrical body. The swellable coating may be applied along only a portion of the length of the apparatus. The swellable coating may be applied as a plurality of elements, e.g. describing regions or layers having different swellable materials, coatings or particles.

The swellable coating may comprise a non-preformed swellable material prior to application. The method may comprise applying the swellable coating to an apparatus in particulate form, e.g. consisting of swellable particles.

The particulate form may comprise one or more of: granules, pellets, powder/s. The particulate form may comprise an indeterminate or non-defined arrangement or relationship between swellable particles of the swellable coating, at least prior to application to an apparatus. The method may comprise not pre-forming the swellable coating prior to application to an apparatus. The method may comprise entraining the swellable particles, such as for fluidized application or spraying.

The swellable coating may be applied in one or more band(s), layer(s) or zone(s), e.g. annular bands. The one or more bands, layers or zones may be arranged along the length, or a portion of the length, of the apparatus. Each band, layer or zone may have a different swellable coating, e.g. configured to swell or expand to different degrees when activated. The bands, layers or zones may be spaced from one another by regions, or further bands, layers or zones free of swellable coating.

The swellable coating may comprise swellable material in a carrier or carrier fluid. The carried fluid may have a swellable material or swellable particles entrained therein. The carried fluid may be or comprise a resin, such as a fluid adhesive resin. The carrier fluid or resin may be configured to adhere to a surface of the apparatus. The carrier fluid may comprise a sellable fluid.

Each layer, band or zone may comprise a different swellable coating, swellable material or swellable particles.

The swellable coating or carrier fluid, once applied to an apparatus, may harden, cure or set. The swellable coating or carrier fluid may comprise a hardening material. Once hardened, cured or set, the swellable coating may be resistant to temperature or impact. The swellable coating may maintain its form, shape, degree of swellability or one or more other properties up to a predetermined threshold temperature.

The swellable coating and/or swellable materials or particles may comprise a resistance to one or more of: chemicals; hydrogen sulphide; acid; high temperature hydrocarbons; high pressure hydrocarbons; temperatures up to 500F, 650F, respectively; pressures up to 18,000psi; temperatures below freezing, such as down to -600.

The carrier fluid or resin may describe or form an adhesive layer. The adhesive layer may describe a matrix. The adhesive layer may be substantially free of swellable particles. The adhesive layer or matrix may be configured to adhere to swellable particles, e.g. so as to form a swellable layer distinct from the adhesive layer.

The swellable coating may be applied to an apparatus by first applying the adhesive layer, e.g. using one or more of the methods as described above. The swellable layer may then be applied by spraying swellable particles onto the adhesive layer. The swellable layer may be applied by dipping the adhesive layer into swellable particles.

In the case where the swellable coating is applied in one or more bands, layers or zones, the adhesive layer may be applied in one or more bands, layers or zones. Different swellable particles may be applied to each band, using one or more methods described above.

The swellable particles may comprise one or more swellable materials. The swellable coating may comprise a mixture of swellable particles or swellable materials. The swellable coating, swellable particles, or one or more swellable materials, may be activated or activatable. The swellable coating, swellable particles, or one or more swellable materials, may be activated in the presence of, in response to, or when they come into contact with an activating material or agent. The activating material or agent may be oil, water or one or more chemicals. Activation of the swellable coating, swellable particles, or one or more swellable materials, may cause them to swell, increase in size or expand, e.g. three-dimensionally so as to press against each other. The activation of swellable particles may cause the swellable coating to increase in size or expand.

to The swellable particles or swellable materials may comprise a coating configured to inhibit or delay swelling. The coating may be sacrificial.

The swellable coating, swellable particles or swellable material(s) may be configured to partially swell in response to contact with a first activating material or agent. The swellable coating, swellable particles or swellable material(s) may be configured to undergo further swelling in response to contact with a subsequent or second activating material or agent.

The swellable coating may be configured to create a seal, e.g. between a casing string and a wellbore, between a casing string and a further casing string, between a liner and a casing string and/or between a tool and a wellbore, casing string or liner string. The swellable coating may be configured to provide an annular seal. The swellable coating may be configured to provide a seal in the case of emergency, e.g. in the event of ingress of water into the wellbore. The swellable coating may be configured to provide a friction or clamping force, e.g. upon activation. The swellable coating may be configured to provide an interference fit, e.g. between adjacent tubular members, upon activation.

The seal may comprise an adaptive seal, such as capable of adapting to changes such as environmental or conditional changes over time. For example, the swellable coating may be configured to swell in the presence of an activating material or agent, e.g. oil and/or water, so as to re-seal or further seal or increase sealing in a subsequent presence of the same of different activating material or agent, e.g. oil and/or water, such as may be associated with changes in the bore subsequent to sealing. By way of example, where downhole pressure changes, such as in a reservoir associated with the bore, establish a fluid path; or where cracks or changes in an associated formation or section of sealed bore, the swellable coating may adapt to re-seal such as by swelling (e.g. to fill the crack/s / block the fluid path).

The swellable coating may be configured to provide a plurality of annular seals, spaced from one another, e.g. when applied in bands as described above. The swellable coating may be configured to isolate a zone, e.g. when applied in bands as described above.

The longitudinal length of the seal provided by the swellable coating, material or particles, may be determined by an amount of swellable coating applied to an apparatus.

The swellable coating may be configured to create a seal upon activation. The swellable to coating may be configured to create a seal when in the presence of, or when in contact with, an activating material or agent.

The swellable coating, swellable particles, or one or more swellable materials, may comprise a polymer. The swellable coating may comprise polymer-based swellable particles or swellable materials.

The swellable coating, swellable particles or one or more swellable materials may be selected from one or more of: a synthetic swellable; a polymer swellable; a polymer-based swellable; a water-swellable swellable; an oil-swellable; a hydrocarbon oil swellable; a swellable activatable by a non-water-based fluid; a swellable activatable by a non-oil-based fluid; an elastomer; a rubber. In at least some examples, the swellable may comprise all of said aforementioned properties or features. In such examples, the swellable may comprise an oil-and water-swellable synthetic elastomeric rubber polymer. In at least some other examples, the swellable may comprise only a limited number of said aforementioned properties or features. For example, in such other examples, the swellable may comprise a water-swellable synthetic elastomeric rubber polymer that is not oil-swellable. In yet other examples, the swellable may comprise an oil-swellable synthetic elastomeric rubber polymer. In at least some examples, the swellable may comprise a swellable in a matrix for application, such as a swellable polymer gel composition for application.

For instance, the swellable coating may comprise a plurality of different types of swellable particles, e.g. oil-swellable particles mixed with water-swellable particles.

The swellable material or swellable particles may have at least a portion with a radius respectively less than 10 mm; less than 5mm; less than 2 mm; less than 1mm; less than 0.1mm; less than 0.01mm. In at least some example methods, at least some swellable particles comprise a diameter less respectively less than 10 mm; less than 5mm; less than 2 mm; less than 1mm; less than 0.1mm; less than 0.01 mm (or doubles thereof). Here, the diameter comprises a nominal diameter.

Referring now to Figure 2, there is shown a schematic cross-sectional side view of a portion of an apparatus 10 according to a first example. Here, the apparatus 10 comprises a cylindrical body 14, the cylindrical body 14 having a central axis 16 and defining a substrate for a swellable coating 12. The cylindrical body 14 describes a central passage 140, e.g. for conveying fluid. The swellable coating 12 is applied along the entire axial length of the cylindrical body 14, in particular, to an outer surface 141 thereof. The swellable coating 12 is in an inactive or non-activated state in this example.

The swellable coating 12 has a substantially uniform thickness along the length of the cylindrical body 14. However, it will be appreciated that this need not be the case.

In at least some examples, the apparatus 10 is a sleeve or a tubular for deployment downhole in an oil/gas wellbore. The swellable coating 12 may be applied at surface, e.g. using one or more of the methods described above, prior to deployment of the apparatus 10. The apparatus 10 may be deployed with the swellable coating 12 in an inactive or non-activated state. The swellable coating 12 may be activated once in contact with, in the presence of or in response to an activating material or agent, once deployed. In the present example, once activated, the swellable coating 12 will expand radially, away from the central axis 16 cylindrical body 14.

It will be appreciated in the case of apparatus 10, the swellable coating 12 is intended to seal, when activated, against a body or member located externally of the apparatus 10. The swellable coating 12 is intended to seal, when activated, against a body or member having a larger diameter than that of apparatus 10, e.g. a wellbore or casing string.

Referring now to Figure 3, there is shown a schematic cross-sectional side view of a portion of another apparatus 110 according to a second example. The apparatus 110 is generally similar to that 10 shown in Figure 2, with like features denoted by like reference numerals, incremented by 100. Accordingly, the apparatus 110 comprises a cylindrical body 114 having a central axis 116 and defining a substrate for a swellable coating 112.

Here, in contrast to Figure 2, the coating 112 is only applied to a portion of the axial length of the apparatus 110. Similarly, rather than being located on an external surface 114a, the coating here is positioned on an inner wall 114b of the cylindrical body 114. As is the case in Figure 2, the swellable coating 112 is shown in an inactive or non-activated state in this example.

As is the case in Figure 2, the swellable coating 112 has a substantially uniform thickness. However, it will be appreciated that this need not be the case. It will be appreciated that the apparatus 110 is a sleeve or a tubular for deployment downhole in an oil/gas wellbore. The swellable coating 112 may be applied at surface, e.g. using one or more of the methods described above, prior to deployment of the apparatus 110. The apparatus 10 may be deployed with the swellable coating 112 in an inactive or non-activated state. The swellable coating 112 may be activated once in contact with, in the presence of or in response to an activating material or agent, once deployed. In the present example, once activated, the swellable coating 112 will expand radially, away from the cylindrical body 114 towards the central axis 116.

It will be appreciated in the case of apparatus 110, contrary to the arrangement of Figure 2, the swellable coating 112 is intended to seal, when activated, against a body or member located internally of the apparatus 110. The swellable coating 112 is intended to seal, when activated, against a body or member having a smaller diameter than that of apparatus 110, e.g. a casing string or liner.

In some examples, the apparatus 110 is a used apparatus 110 that has previously been deployed and has been worn or damaged, with the coating 112 providing a means for accommodating play or undesired tolerances or tolerance breaches associated with the wear or damage.

Referring now to Figure 4, there is shown a schematic cross-sectional sideview of a portion of an apparatus according to another example. The example shows a swellable coating 212 applied to an apparatus 214, e.g. a sleeve or tubular, forming a substrate. Here, an additional coating 218 is applied as external layer on top of the swellable coating 212. The additional coating 218 may comprise a temporary coating, such as to protect the swellable coating 212 during deployment, transport to a well location and/or run-in downhole. The additional coating 218 may be configured to protect the swellable coating 212 from impact or damage during deployment, transport to a well location and/or when run-in downhole.

Alternatively, the additional coating may comprise a long-term coating, such that the swellable coating 212 remains concealed, protected or at least unexposed during at least a portion of use of the apparatus 210. For example, the swellable coating 212 may be provided as a remedial, redundant or back-up coating. The additional coating 218 may comprise a further swellable coating. The swellable coating 212 may be provided as a secondary swellable coating. The secondary swellable coating may provide a remedial or back-up coating, e.g. configured to provide or reinforce a seal in the event that the additional coating 218 wears or deteriorates. The distinct coatings 212, 218 may be swellable in response to the same and/or different activating fluids. For example, the outer coating 218 may be swellable in the presence of oil; whilst the swellable coating 212 may be swellable in a presence of water (and optionally also oil).

The additional coating 218 may comprise a protective coating, shield or barrier layer.

The additional coating may be configured to protect the swellable coating 212 from an activating material or agent, e.g. so as to maintain the swellable coating 212 in an inactive or non-activated state until desired. The additional coating 218 may be or comprise a sacrificial layer. The additional coating 218 may be configured to at least partly dissolve, deteriorate, disintegrate, dissipate or break-down in the presence of an activating material or agent. The additional coating 218 may be configured to at least partly dissolve, deteriorate, disintegrate, dissipate or break-down over a predetermined period of time, e.g. so as to provide timing management, a time period or window in which the apparatus can be located or deployed without activating the swellable material.

The additional coating 218 may be a porous or substantially porous material. The additional coating 218 may be configured to allow an activating material or agent to reach or contact the swellable material. The additional coating 218 may be a permanent layer. The additional coating 218 may be configured to seal against a wellbore or other tubular member upon activation of the swellable material 212. The additional coating 218 may be configured to provide a more effective seal than the swellable material 212. The additional coating 218 may be or comprise an elastomeric material. The additional coating may be configured to be forced against another tubular member upon activation of the swellable material 212.

Figure 5 is a schematic sectional side view of a portion of a well in accordance with an example. The apparatus 310 here comprises a casing or tubing patch, such as for bridging a damaged section of tubing or casing. The damaged section of tubing or casing may have been removed (as shown in Figure 5), such as by milling, drilling or the like, leaving an upper tubing or casing section 320 and a lower tubing or casing section 322 separated by an open section 324. Alternatively, the damaged section of tubing or casing may remain in situ, with the patch 310 being located radially internally thereof.

Here, the apparatus 310 comprises a cylindrical body 314. The cylindrical body 314 has a central axis 316 that coincides with the central axes of upper and lower sections 320, 322. In the present example, the cylindrical body 314 has a smaller diameter than the upper and lower sections 320, 322. A portion at either end of the cylindrical body 314 overlaps with a respective upper and lower section 320, 322 by a distance L. Together, the cylindrical body 314, upper section 320 and lower section 322 define a conduit C for conveying fluid.

The cylindrical body 314 describes a similar arrangement to that of Figure 2, and defines a substrate for a swellable coating 312. The swellable coating 312 is applied along the entire axial length of the cylindrical body 314, in particular, to an outer surface 314a thereof. The swellable coating 312 is in an inactive or non-activated state in this example.

As shown in greater detail in Figure 5a, the well of Figure 5 is in a first configuration, with the swellable coating 312 in an inactive or non-activated state. In this state, a gap or space G is described between the outer surface 314a of the cylindrical body 314, and an internal surface 320a of the upper section 320. It will be appreciated that in the present example, the gap or space G is annular, and present between the cylindrical body 314 and both the upper section 320 and lower section 322. In the present configuration, with the swellable coating 312 in an inactive or non-activated state, the conduit C is not fluid fight, and therefore is not suitable for conveying fluid.

The swellable coating 312 has a substantially uniform thickness along the length of the cylindrical body 314. However, it will be appreciated that this need not be the case.

Once the cylindrical body 314 is correctly positioned, the swellable coating 312 can be activated to as to seal against an internal surface of each of the upper section 320 and lower section 322. The seal is configured to provide a fluid tight conduit C. An activating material or agent is brought into contact with the swellable coating 312, which subsequently expands away from the central axis 316 towards the internal surface of each of the upper section 320 and lower section 322. Figure 5b shows the detail of the well of Figure 5 in a second configuration, with the coating 312 in an activated state. In this case, the swellable coating 312 is in contact with, and seals against the internal surface 320a of the upper section 320. It will be appreciated that the swellable coating 312 will also contact, and seal against, the internal surface of the lower section 322, in a similar manner.

Referring now to Figure 6, there is shown a schematic cross-sectional sideview of a portion of an apparatus 410 according to another example. The apparatus 410 is generally similar to apparatus 310 shown in Figure 5, with like features denoted by like reference numerals, incremented by 100.

Accordingly, the apparatus 410 comprises a cylindrical body 414 having a central axis 416 and defining a substrate for a swellable coating 412.

to The apparatus 410 shown in Figure 6 comprises a screwthread portion 418, configured to engage a cooperating screwthread portion 422 of a tubular member 420. The tubular member 420 may be a tubing, casing or liner section, e.g. having a threaded free-end. The apparatus 410 may comprise a corresponding tubing, casing or liner section. The apparatus 410 and tubular member 420 are connected via the cooperating screwthread portions 418, 422.

In examples, the apparatus 410 may comprise or be a valve or control mechanism, configured to be connected with a tubular member 420. The swellable coating 412 can be applied to at least one of the components of the screwthread 418, 422 (e.g. male and/or female) prior to mating of the screwthreads 418, 422. Additionally, or alternatively, the swellable coating 412 may be applied during and/or after the mating or engaging of the screwthreads 418, 422. The swellable coating 412 may be applied by injecting into the region between the screwthreads 418, 422. The swellable coating 412 may be applied according to any method heretofore mentioned, or any other suitable method.

In the present example, the swellable coating 412 is depicted as being located between the screwthreads 418, 422, and in contact with each. The swellable coating 412 is in an inactive or non-activated state when applied to one or each of screwthreads 418, 422. The swellable coating 412, in the present example, may be activated either prior to, or after, locating the apparatus 410 and tubular member 420, e.g. in a downhole location.

The swellable coating 412 may be activated by applying an activating material or agent thereto. Once activated, the swellable coating 412 will expand between the screwthreads 418, 422, e.g. so as to provide a fluid tight seal at the connection between the apparatus 410 and tubular member 420.

It will be appreciated that any of the aforementioned devices may have other functions in addition to the mentioned functions, and that these functions may be performed by the same device The applicant hereby discloses in isolation each individual feature described herein and any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the present specification as a whole in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features solve any problems to disclosed herein, and without limitation to the scope of the claims.

The applicant indicates that aspects of the present disclosure may consist of any such individual feature or combination of features. It should be understood that the embodiments described herein are merely exemplary and that various modifications may be made thereto without departing from the scope of the disclosure. For example, it will be appreciated that although shown here as a bore with a vertical orientation, other bores may have other orientations. For example, other example bores may have at least non-vertical portions, such as deviated or horizontal sections or bores.

It will be appreciated that example or embodiments can be realized in the form of hardware, software or a combination of hardware and software. Any such software may be stored in the form of volatile or non-volatile storage, for example a storage device like a ROM, whether erasable or rewritable or not, or in the form of memory; for example RAM, memory chips, device or integrated circuits or on an optically or magnetically readable medium, for example a CD, DVD, magnetic disk or magnetic tape or the like. It will be appreciated that the storage devices and storage media are embodiments of machine-readable storage that are suitable for storing a program or programs comprising instructions that, when executed, implement embodiments of the present disclosure.

Accordingly, examples or embodiments provide a program comprising code for implementing apparatus or a method as claimed in any one of the claims of this specification and a machine-readable storage storing such a program. Still further, such programs may be conveyed electronically via any medium, for example a communication signal carried over a wired or wireless connection and embodiments suitably encompass the same.

Claims

CLAIMS1. A method of applying a swellable to an apparatus for deployment in a bore, wherein the method comprises applying the swellable as a coating.
2. The method of claim 1 wherein the method comprises applying the swellable as a particulate in the coating.
3. The method of claim 1 or claim 2, wherein the coating is applied by deposition.
4. The method of any preceding claim, wherein the method comprises applying the coating as a fluid and hardening or setting the fluid to or on the apparatus.
The method of any preceding claim, wherein the method comprises entraining the swellable in a carrier fluid for application to the apparatus; and applying the swellable as a particulate within a mixture.
6 The method of claim 5, wherein the fluid comprises an adhesive; and the method comprises adhering the swellable to the apparatus as a substrate with the adhesive.
7. The method of any preceding claim, wherein the method comprises providing a layer on top of the swellable coating.
8. The method of claim 7, wherein the layer comprises a protective layer, such as to protect the swellable coating from the environment.
9. The method of claim 7 or 8, wherein the layer comprises a temporary layer.
10. The method of any preceding claim, wherein the method comprises exposing at least a portion of the/each swellable particle.
11. The method of any preceding claim, wherein the method comprises applying the swellable as an exterior coating on the apparatus.
12. The method of any preceding claim, wherein the method comprises providing the swellable as an interior coating on the apparatus.
13. The method of any preceding claim, wherein the method comprises coating a plurality of components of the apparatus prior to assembly and/or when in an assembled configuration.
14. The method of any preceding claim, wherein the method comprises providing the swellable as a back-up, redundant or emergency coating.
15. The method of any preceding claim, wherein the method comprises applying the coating to at least a portion of a screwthread.
16. The method of any preceding claim, wherein the method comprises applying the swellable so as to form an annular coating.
17. The method of any preceding claim, wherein the method comprises providing the coating at a first thickness and configuring the coating to swell to a second thickness, the second thickness being greater than the first thickness; and the coating is configured to provide and/or compensate for a fit and/or clearance.
18. The method of any preceding claim, wherein the method comprises the repair of an apparatus.
19. The method of any preceding claim, wherein the method comprises retro-fitting the coating to a used, pre-existing or aged apparatus.
20. The method of any preceding claim, wherein the method comprises providing a swellable at a downhole control line to provide a permanent or temporary sheath or protection around the control line.
21. The method of any preceding claim, wherein the method comprises machining the coating during and/or after application.
22. The method of any preceding claim, wherein the method comprises applying the swellable so as to fill a gap.
23. An apparatus comprising the coating of any preceding claim.
24. The apparatus of claim 23, wherein the apparatus comprises one or more of: a valve; a packer; an intervention tool; a plug; a tubular; a casing; a bridge; a patch; a clamp; a control line; a wireline apparatus; a coiled-tubing apparatus.
25. The apparatus of claim 23 or claim 24, wherein the apparatus comprises a screwthread with the swellable coating applied.