CLAMP APPARATUS

Abstract

The present disclosure generally relates to anode clamp apparatus for a subsea cathodic protection system, the anode clamp apparatus comprising: a frame, the frame being arranged to at least partly define a receiving space for receiving at least part of a subsea object to be clamped, at least one contact pin coupled to the frame and arranged to protrude at least partly into the receiving space, the contact pin being electrically conductive; and a tensioning unit coupled to the contact pin, the tensioning unit arranged to bias the contact pin towards the receiving space. The present disclosure further relates to a subsea structure comprising the coupling apparatus, and a method using the apparatus. Unlocking insights from geodata, the present disclosure further relates to improvements in sustainability and environmental developments: together we create a safe and liveable world. (Fig. 1)

Description

TECHNICALFIELD

[0001] This disclosure relates to anode for a subsea cathodic protection system. The disclosure further relates to a method of using the anode . The disclosure further relates to a subsea structure and / or a cathodic protection system for a subsea structure. Unlocking insights from Geo-Data, the present invention further relates to improvements in sustainability and environmental developments: togetherwe create a safe and liveable world. BACKGROUND

[0002] There is a general and ongoing need to improve the efficiency and quality of subsea operations and the provision of subsea structures and infrastructure. Subsea operations are becoming an increasingly important part of the energy transition. However, these operations and structures also face an increased demand on durability and reliability in extreme environmental conditions, leading to a need for improved approaches. In particular, there is a need for apparatus, systems and / or methods that can be used for cathodic protection of such systems.

[0003] In typical subsea structures such as those for gas, oil orwind power, corrosion may negatively affect the strength, durability, and / or integrity of the structure if not appropriately mitigated. In particular, if a subsea structure has components of two suff1ciently dissimilar metals, with an electrically conductive path between them, then the seawater may act as an electrolyte and enable currentow through the water from an anode site (a more active site) to a cathode site (a less active site), thereby causing an electrochemical reaction that leads to corrosion of at least one ofthe metals. In many cases, such corrosion can occur in a single piece of steel that has metallurgical differences across its surface and which can experience a current ow through the waterfrom a more active site on the surface to a less active site on the surface.

[0004] Conventional approaches for preventing this corrosion use cathodic protection systems that are based on providing sacrif1cial galvanic anodes that are more electrochemically active than the metal(s) (e.g., steel) of the subsea structure. Providing anodes in this manner effectively converts the anodic active sites on the metal surface of the subsea structure to cathodic (passive) sites, thereby protecting the subsea structure from corrosion. The subsea structure is designed with these anodes welded or bolted to the structure in order to provide the electrical connection that is required to enable them to function as a sacricial component that prevents corrosion from occurring to the main structure. Such welding or bolting takes place prior to installation or placement ofthe structure into the water.

[0005] In cathodic protection systems, it is imperative to establish a reliable electrical connection between the sacricial anode and the structure being protected. This connection must remain intact and effective throughout the operational life of the system to ensure continuous protection against corrosion. The integrity of this connection is crucial, as any disruption can lead to localized corrosion and potential structural failure.

[0006] However, each anode has a nite lifetime over which it can protect the main structure. Accordingly, the overall structure lifetime and / or durability can be limited by the properties of the anodes attached prior to installation. Likewise, changing operational or environmental conditions may mean that the anodes provided at the installation ofthe subsea structure may no longer provide the desired protection. However, maintenance or repair of anodes can be highly costly and can be operationally challenging. It is therefore challenging to extend or prolong the operational lifetime of subsea structures.

[0007] Known devices for providing a physical connection with a subsea structure utilize a xed frame with a threaded pin with a pointed end, which is forced onto the subsea structure to form the contact point. A problem associated with these devices is that the contact point which engages with the main structure may corrode over time. The corrosion of the contact point and / or the frame to which the threaded pin is connected, or corrosion ofthe material of the subsea structure, can result in a reduction of the force exerted on the subsea structure and could lead to the connection being lost. In more disadvantageous situations, this may lead to the frame falling from the subsea structure completely and it being lost. Vibrations from wave or currentmotions can also cause the threaded connection to come undone, and / or to accelerate the corrosive degradation ofthe device.

[0008] There is a need for an improved apparatus and methods for a subsea cathodic protection system. This disclosure aims to solve at least one ofthe abovementioned problems. OVERVIEW

[0009] Disclosed herein is an anode that can generally facilitate tting, replacement and / or retrotting ofsacricial anodes for cathodic protection to a subsea structure in a safe and secure manner, thereby enabling the operational lifetime of the subsea structure to be extended. Additionally or alternatively, the anode disclosed herein may be used for electrically grounding a subsea obj ect. For example, the anode may be clamped to a subsea structure and / or object to provide electrical continuity between that object and a ground or earth connection and / or point. In a particular example, the anode disclosed herein may be used for instating or re-instating an earth point connection between apparatus such as an SCM (subsea control module) and a subsea structure or frame.

[0010] Anode for a subsea cathodic protection system is disclosed. The anode comprises: a frame, the frame being arranged to at least partly dene a receiving space for receiving at least part of a subsea object to be clamped, at least one contact pin coupled to the frame and arranged to protrude at least partly into the receiving space, the contact pin being electrically conductive, and a tensioning unit coupled to the contact pin, the tensioning unit arranged to bias the contact pin towards the receiving space.

[0011] The anode enables an improved approach for simply and securely retrotting anodes to subsea cathodic protection systems. Advantageously, the tensioning unit being arranged to bias the contact pin towards the receiving space enables electrical continuity with a clamped subsea structure to be maintained even in conditions that would otherwise disrupt or degrade the initial contact between the pin and structure, such as corrosion-induced loss ofmaterial. Accordingly, the durability and reliability of cathodic protection systems can be improved, thereby extending the possible lifetime ofan associated subsea structure.

[0012] As used herein, the term anode refers to examples of an apparatus that comprises an anode itself (and thus can function as a standalone sacricial anode) and examples ofan apparatus that does not comprise an anode butmay be used to clamp an anode or associated structure (such as cabling for an anode or anode sled) to a subsea structure. In other words, the anode itself need not necessarily comprise an anode component for a subsea cathodic protection system, but in some examples may indeed comprise an anode.

[0013] In some examples, the tensioning unit comprises at least one spring arranged concentrically around the contact pin.

[0014] Advantageously, arranging the spring concentrically around the contact pin enables a constant force to be applied directly to the contact pin by the spring. Furthermore, by using a spring arranged around the contact pin, a compact tensioning unit can be provided that does not take up much space in the apparatus. Accordingly, the overall shape of the anode can be formed in a large variety ofways, which may each be specic to a purpose and / or geometry, thereby enabling a wider variety of cathodic protection systems to be implemented. By having the at least one spring provided around the contact pin, and thus reducing the complexity, the durability ofthe system is improved.

[0015] In some examples, the at least one spring is a Belleville washer.A Belleville washer may also be known as one or more of: a coned-disc spring, conical spring washer, disc spring, Belleville spring, or cupped spring washer.

[0016] Advantageously, this type of spring can be particularly reliable, with a high service life, can be compact in size, and can provide concentric force transmission on the contact pin.

[0017] In some examples, the tensioning unit comprises a cover arranged to house at least a portion of the contact pin, the portion of the contact pin comprising a protruded rim, the at least one spring being arranged between an inner surface ofthe cover and the protruded rim to bias the contact pin towards the receiving space.

[0018] Advantageously, such examples enable the tensioning unit to be pre-tensioned. The spring can therefore be compressedwhen the anode is closed around an object and the contact pin is pressed against the object. Ifthe pressing ofthe contact pin on the object is reduced, such as due to movement ofthe apparatus underwater and / or due to the surface of the object losing material due to corrosion, the spring can relax from its compressed state and push the contact pin towards the object.

[0019] In some examples, the contact pin extends through an opening in the frame and the contact pin comprises a protruded rim, the at least one spring being arranged between a surface ofthe frame and the protruded rim to bias the contact pin towards the receiving space.

[0020] Advantageously, such examples likewise enable the tensioning unit to be pre- tensioned.

[0021] In some examples, the frame comprises a rst arm and a second arm, the rst arm and the second arm being connected via a hinge, wherein the rst arm and the second arm are arranged to at least partly dene respective sides ofthe receiving space.

[0022] Advantageously, use of a hinge and arms enables a mechanical compression force to be provided onto the clamped object from two sides, and that force is independent of the tensioning on the contact pin, thereby further helping to ensure that the contact pin remains in contact with the object.

[0023] In some examples, the rst and the second arm each comprise a distal end and a proximal end, the contact pin is coupled to the frame towards the distal end of at least one of the rst and second arms, and the hinge is arranged away from the distal end ofthe respective rst and second arms.

[0024] Advantageously, such examples enable a pinch-like positioning of the contact pin on the frame ofthe anode , which may be particularly suitable for attaching to a subsea object in challenging environmental conditions.

[0025] In some examples, at least one ofthe rst arm and the second arm comprises a slot arranged further towards the respective proximal end than the hinge is arranged, the slot arranged to receive a clamp adjustment mechanism.

[0026] Advantageously, such examples enable the clamping function of the anode to be adjusted from the proximal end, reducing the risk ofinterfering with the contact pin during installation and / or adjustment.

[0027] In some examples, at least one ofthe rst arm and the second arm comprises a slot arranged further towards the respective distal end than the hinge is arranged, the slot arranged to receive a clamp adjustment mechanism.

[0028] Advantageously, such examples can be particularly suitable for clamping to larger objects.

[0029] In some examples, the contact pin is arranged at a rst side oftwo opposing sides ofthe receiving space and a second contact pin is arranged at a second side ofthe two opposing sides ofthe receiving space, the second contact pin being electrically conductive.

[0030] Advantageously, such examples enable improved reliability ofconnection between the contact pin and a clamped object, through enabling connection to be made on two sides of an obj ect.

[0031] In some examples, the contact pin is arranged at a rst side oftwo opposing sides ofthe receiving space and a second contact pin is arranged at the rst side ofthe two opposing sides, the second contact pin being electrically conductive.

[0032] Advantageously, such examples enable improved reliability ofconnection between the contact pin and a clamped object, through enabling redundant connections on the same side ofan obj ect.

[0033] In some examples, the tensioning unit is arranged to bias each of the contact pins towards the receiving space.

[0034] Advantageously, such examples enable yet further improved reliability of electrical connection between the anode and the clamped obj ect.

[0035] In some examples, the anode further comprises a clamp adjustment mechanism for tightening and / or loosening the frame around a subsea object to be clamped

[0036] Advantageously, such examples enable improved usability of the anode , and allow the clamping force to be appropriately adjusted to the environment.

[0037] In some examples, the clamp adjustment mechanism comprises a plastic bushing arranged around a threaded fastener, the threaded fastener being coupled to the frame for tightening and / or loosening the frame around a subsea object to be clamped.

[0038] Advantageously, the bushing can provide resistance to any thread back-off of the threaded fastener due to vibration or other environmental forces, thereby ensuring the fastener stays in the intended position and that therefore the frame stays clamped around the obj ect.

[0039] In some examples, the clamp adjustmentmechanism comprises: atorque connector, a lead screw comprising a threaded section extending between a distal and a proximal end, and a drive unit arranged between the frame and the torque connector and arranged to engage with the threaded section ofthe lead screw such that rotation ofthe lead screw results in movement ofthe drive unit along the lead screw in relation to the frame, the lead screw being rotationally coupled to the frame and longitudinally extending away from the drive unit and towards and extending into the torque connector such that a torque can be applied to the lead screw, the drive unit being coupled to the frame such that relative movement between the frame and the drive unit in a rst direction causes the receiving space at least partly dened by the frame to widen and relative movement between the frame and the drive unit in a second direction causes the receiving space at least partly dened by the frame to narrow.

[0040] Advantageously, such examples enable improved usability of the anode and provide a reliable mechanism for applying torque under the sea in order to have the anode close about an object by narrowing the receiving space, so as to secure the anode in the desired position.

[0041] In some examples, the clamp adjustment mechanism is arranged to be operated by a remotely operated vehicle.

[0042] Advantageously, such examples enable an improvement to the versatility of approaches that can be used for retrotting the anode . In particular, operation by a remotely operated vehicle can improve safety during tting ofthe anode .

[0043] In some examples, the clamp adjustment mechanism further comprises an anode.

[0044] Advantageously, such examples enable a particularly compact implementation of a retrotted anode for a subsea cathodic protection system because the anode can be tted as part ofthe anode and can be directly clamped to a subsea object. Accordingly, the anode can be less challenging to retrot to a subsea object or structure.

[0045] In some examples, the anode comprises at least one of: a zinc based anode and / or an aluminium based anode.

[0046] In some examples, the anode is formed as a disc.

[0047] In some examples, the anode further comprises an electrically conductive wire arranged to electrically couple the contact pin to the anode.

[0048] Advantageously, the electrically conductive wire enables improved electrical connection between the contact pin and the anode.

[0049] In some examples, the anode is a rst anode and the anode further comprises a second anode, the rst anode being coupled to the frame on a rst side of the receiving space and the second anode being coupled to the frame on a second side of the receiving space.

[0050] Advantageously, such examples enable redundancy of connection between a clamped object and an anode, and thus improved reliability ofcathodic protection.

[0051] In some examples, the at least one contact pin comprises a plurality ofcontact pins and each ofthe rst and the second anode is electrically coupled to a respective contact pin.

[0052] Advantageously, such examples enable redundancy of connection between a clamped object and an anode, and thus improved reliability ofcathodic protection.

[0053] Also disclosed is a cathodic protection system for a subsea structure, the cathodic protection system comprising the anode disclosed herein.

[0054] Also disclosed is a subsea structure comprising the anode disclosed herein.

[0055] Also disclosed is a method ofusing the anode disclosed herein, the method comprising using the anode in a subsea cathodic protection system.

[0056] The term apparatus as used herein may refer to either a single apparatus or plural apparatus and should not be understood as being particularly limited to either a single discrete apparatus or a plurality of discrete apparatus unless a particular apparatus is further described as such.

[0057] The term subsea structure as used herein is used to refer to structure(s) and / or infrastructure(s) that are at least partially submerged orimmersed in water, such as a sea, ocean, and / or lake. Such structure(s) and / or infrastructure(s) may also be considered to be offshore. Similarly, the term subsea object is used herein to refer to at least part of such a subsea structure that is immersed or submerged.

[0058] The term coupled as used in at least some instances herein refers to a mechanical arrangement in which components may be directly or indirectly connected to one another. For example, in relation to a contact pin coupled to a frame, the contact pinmay be at least partially held in place by the frame itself, or some other component (such as a tensioning unit and / or housing) can be arranged between the frame and the contact pin, attached to the frame, and used to hold the contact pin in place, thereby providing coupling between contact pin and frame. The coupling or connection between the components need not be rigid (although in some instances it may be) and, for example, the contact pin may have a range of possible motion relative to the frame and the frame may be arranged to retain the contact pin within that range ofmotion.

[0059] The above mentioned and other features and advantages of the disclosure will be best understood from the following description referring to the attached drawings. In the drawings, like reference numerals denote identical parts or parts performing an identical or comparable function or operation. BRIEF DESCRIPTIONOF THEDRAWINGS

[0060] In order to describe the manner in which the above-recited and other advantages and features of the disclosure can be obtained, a more particular description ofthe principles briey described above will be rendered by reference to specic embodiments thereofwhich are illustrated in the appended drawings. Understanding that these drawings depict only exemplary embodiments ofthe disclosure and are therefore not to be considered to be limiting of its scope, the principles herein are described and explained with additional specicity and detail through the use ofthe accompanying drawings in which:

[0061] FIG. 1 shows a subsea structure with a cathodic protection system.

[0062] FIG. 2 shows an exemplary anode for a subsea cathodic protection system, according to the present disclosure,

[0063] FIG. 3 shows the anode from a different perspective,

[0064] FIG. 4 shows the anode from another different perspective,

[0065] FIG. 5 shows a cross sectionview ofthe anode ,

[0066] FIG. 6 shows an example of a tensioning unit according to the present disclosure,

[0067] FIG. 7 shows another example of a tensioning unit according to the present disclosure, and

[0068] FIG. 8 shows a schematic diagram showing a method of using an anode , according to the present disclosure. DETAILED DESCRIPTION

[0069] Examples contemplated by the present disclosure will now be described in more detail with reference to the accompanying drawings. The disclosed subject matter should not be construed as limited to only the embodiments set forth herein. Rather, the illustrated embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0070] FIG. 1 shows a subsea structure 100 with a cathodic protection system. The subsea structure 100 comprises a subsea object 101. In the example ofFIG. 1, the subsea object 101 is partially submerged below a water surface 102 of a body ofwater such as the sea. However, it will be understood that the present disclosure is not limited only to partially submerged subsea objects and that in other examples the subsea object and / or structure may be fully submerged below the water surface 102.

[0071] The subsea object 101 may be, for example, a structural component ofthe structure 100, such as a pipeline or a support component for an offshore platform, that is at least partly made ofmetal and is susceptible to corrosion.A typical form of such corrosion is the corrosion of steel in seawater wherein the seawater acts as an electrolyte. In such conditions, ifthe steel has metallurgical differences across its surface, at a more active part of surface, iron (2Fe) may convert into iron ions plus free electrons (2Fe++ + 4e'). The free electrons may be conducted by the steel to the less active site(s) on the surface, where a reaction to convert oxygen gas to oxygen ions by combining with the free electrons takes place to form hydroxyl ions. Consequently, at the active surface, the iron in the steel may combine with oxygen and water to form ferrous hydroxide, a corrosion product. This process can also be considered as a current ow through the water from the more active anode site(s) on the surface ofthe metal to the less active cathode site(s). As will beunderstoodby the skilled person, other subsea corrosion reactions may also take place, whichmay depend on the metals and / or alloys used in the subsea obj ect. For example, a corrosion reaction may take place iftwo dissimilar metals are used in a subsea object and the two dissimilar metals have an electrically conductive path between them.

[0072] In order to prevent and / or reduce this corrosion, a subsea cathodic protection system can be used. The subsea cathodic protection system comprises an anode 103 and an electrically conductive connection 104 between the anode 103 and the subsea object 101. The subsea cathodic protection system is submerged below the water surface 102 and the electrically conductive connection 104 is connected to the subsea object 101 at a part ofthe subsea object 101 that is submerged below the water surface 102.

[0073] The anode 103 functions as a sacricial galvanic anode that is more electrochemically active than the metal(s) (e.g., steel) ofthe subsea object 101. The electrically conductive connection 104 between the anode 103 and the subsea object 101 effectively converts the anodic active sites on the metal surface of the subsea object 101 to cathodic (passive) sites, thereby protecting the subsea object 101 from corrosion. Conventionally, the subsea structure is designed with these anodes welded and / or bolted to the structure below the water surface in order to provide the electrical connection that is required to enable them to function as a sacricial component that prevents corrosion from occurring to the main structure. Such welding or bolting takes place prior to installation or placement ofthe structure into the water. In some approaches, an anode sled may be used, and the anode sled may comprise a cable that functions as the electrically conductive connection 104.

[0074] As an example, ifan aluminium anode is used to protect a steel-based subsea object, the reaction at the aluminium surface will convert aluminium (4A1) to aluminium ions (4Al++) plus (12) free electrons. Those free electrons are conducted to the surface of the steel. At the surface ofthe steel, oxygen gas will combine with the free electrons andbe converted to oxygen ions which combine with water to form hydroxyl ions. However, so long as the free electrons arrive at the steel surface faster than oxygen does, no corrosion will occur.

[0075] It will be understood that, in other implementations, different materials and / or reactions may be used. For example, the sacricial anode may be formed of zinc, rather than aluminium.

[0076] Changing operational or environmental conditions may mean that the anodes provided at the installation ofthe subsea structuremay no longer provide the desired protection. However, maintenance or repair of anodes can be highly costly and can be operationally challenging. Disclosed herein is an anode that can generally facilitate replacement and / or retrotting of sacricial anodes to a subsea structure in a safe and secure manner, thereby enabling the operational lifetime ofthe subsea structure to be extended.

[0077] FIG. 2 shows an exemplary anode 200 according to the present disclosure. FIG. 3 shows the anode 200 ofFIG. 2 from a different perspective.

[0078] The anode 200 is for a subsea cathodic protection system like those described herein, such as the subsea cathodic protection system of FIG. 1. For example, the anode 200 may be used in the subsea cathodic protection system and / or to secure the subsea cathodic protection system to a subsea object and / or structure such as the subsea object 101 and subsea structure 100 ofFIG. 1. Accordingly, the anode 200 is suitable for installation and use on part of a subsea object (such as the subsea object 101 ofFIG. 1) below the water surface.

[0079] The anode 200 may be formed in different arrangements, as described herein, depending on the desired application, and, depending on the implementation, may be suitable for use on subsea objects including but not limited to parts of oil and gas platforms, well-heads, renewable monopiles, objects having at surfaces, objects having a tubular shape, mooring chains, pipes, pipelines, and / or columns.

[0080] The anode 200 comprises a frame 210, the frame 210 being arranged to at least partly dene a receiving space 211 for receiving at least part of a subsea object to be clamped. The subsea objectmay correspond to the subsea object 101 ofFIG. 1 and related examples described herein. It will be understood that the anode 200 may be moved by an operator such that the subsea object 101 may at least enter the receiving space 211 dened by the frame 210 and the frame 210 may be pressed onto or around the subsea object 101 such that the anode 200 is clamped to the subsea object 101.

[0081] The frame thus denes a receiving space such that the frame may be used to provide a clamp function around the receiving space. For example, in some examples, the frame may be closeable or able to be tightened such that the receiving space is largely or entirely reduced, and may be openable or able to be loosened such that the receiving space is larger and / or wider and able to receive ormove onto an object. It will be understood that the frame may therefore have an effective range of motion or range of congurations that correspond to the frame dening a range of different size receiving spaces. In many examples, particular positions or congurations ofthe frame (particularly those at an intermediate conguration ofany range of congurations ofthe frame) may dene a receiving space in which multiple edges or sides of the receiving space are dened by edges and / or sides of the frame, and an opening into the receiving space for receiving an object to be clamped is also present and left as a gap by the frame.

[0082] The anode 200 further comprises at least one contact pin 220 coupled to the frame 210 and arranged to protrude at least partly into the receiving space 211, the contact pin being electrically conductive. When the frame is appropriately pressed, closed, and / or tightened onto or around the subsea object 101, the at least one contact pin 220 will come into contact and / or press against the subsea object 101. In many implementations, the contact pin 220 will be constructed such that it can penetrate the surface of the subsea object 101 in order to provide electrical continuity between the subsea object 101 and the contact pin 220. In examples described in more detail below, more than one such contact pin may be used.

[0083] The anode 200 further comprises a tensioning unit 230 coupled to the contact pin 220, the tensioning unit 230 arranged to bias the contact pin 220 towards the receiving space 211. The tensioning unit 230 can therefore bias the contact pin 220 towards or into a subsea object 101 that is appropriately located within the receiving space 211.

[0084] In some examples, the tensioning unit comprises at least one spring arranged concentrically around the contact pin 220. The spring may provide a biasing force to push, press and / or bias the contact pin 220 towards the receiving space 211. Exemplary implementations ofthe tensioning unit 230 are further described herein in relation to FIGS. 6 and 7.

[0085] Exemplary further features ofthe anode 200 as shown in FIGS. 2 to 5 will now be described. It will be understood that, in other examples, other arrangements of a frame may be used instead.

[0086] The frame 210 comprises a rst arm 215 and a second arm 216, the rst arm 215 and the second arm 216 being connected via a hinge 217, wherein the rst arm 215 and the second arm 216 are arranged to at least partly dene respective sides of the receiving space 211. The hinge 217 allows the rst arm 215 to rotate with respect to the second arm 216, and / or vice versa, such that the arms together can operate as a clamp that is openable or closeable (or, in other words, can be loosened or tightened) around a subsea obj ect.

[0087] The rst arm 215 comprises a proximal end 215a and a distal end 215b. The second arm 216 comprises aproximal end216a and a distal end 216b. In some examples (and as shown in FIGS. 2 to 5) wherein the rst and the second arm each comprise a distal end and a proximal end, the contact pin is coupled to the frame towards the distal end of at least one ofthe rst and second arms, and the hinge is arranged away from the distal end of the respective rst and second arms. It will be understood that the hinge being arranged away from the distal end of the respective rst and second arms means that the hinge is arranged on each of the rst and second arms further away from the distal end than where the contact pin is arranged on whichever ofthe rst or second arms the contact pin is arranged on. The hinge may be located towards, at, or near the proximal end of the respective rst and second arms, rather than towards, at, or near the distal end of the respective rst and second arms. In some examples, the hinge may be located towards a central point located equidistant between the proximal end and distal end ofthe respective arms, which may still be considered to be away from the distal end.

[0088] In some examples, at least one of the rst arm 215 and the second arm 216 comprises a slot 218 arranged further towards the respective proximal end than the hinge 217 is arranged, the slot 218 arranged to receive a clamp adjustment mechanism. In the examples ofFIGS. 2 to 5, such a slot 218 is shown in the rst arm 215 and contains a drive pin 219 ofa clamp adjustment mechanism 270.

[0089] In some examples, the position of the slot 218 along the respective rst or second arm may be different to that shown in FIGS. 2 to 5. In some examples, at least one ofthe rst arm 215 and the second arm 216 comprises a slot arranged further towards the respective distal end than the hinge 217 is arranged, the slot arranged to receive a clamp adjustment mechanism.

[0090] The anode 200 may comprise any suitable number ofcontact pins like the contact pin 220. In the example shown in FIGS. 2 to 5, four contact pins 220, 221, 222, 223 are used (note that each gure may show only a subset ofthe four contact pins).

[0091] Ifmultiple pins are used, those pins may be positioned differently depending on the implementation. For example, in some examples, the contact pin is arranged at a rst side of two opposing sides ofthe receiving space and a second contact pin is arranged at a second side of the two opposing sides of the receiving space, the second contact pin being electrically conductive. Such an arrangement may take the form ofan anode such as that of FIGS. 2 to 5 in which, for example, only contact pins 220 and 222 are present. In that example, by arranging each contact pin 220, 222 on a different respective arm ofthe rst and second arms 215, 216, the contact pins 220, 222 are arranged on respective sides of two opposing sides ofthe receiving space 211.

[0092] In some examples, the contact pin is arranged at a rst side oftwo opposing sides ofthe receiving space and a second contact pin is arranged at the rst side ofthe two opposing sides, the second contact pin being electrically conductive. For example, such examples may correspond to an implementation of the anode 200 ofFIGS. 2 to 5 in which only the contact pins 220, 221 on the rst arm 215 are present, and the contact pins 222, 223 on the second arm 216 are not or vice versa.

[0093] It will be understood that other combinations are also possible. For example, an arrangementmay be used in which a single contact pin is provided on one side ofthe receiving space (and / or on the rst arm) and two or more contact pins are provided on another side of the receiving space (and / or on the second arm).

[0094] Whichever arrangement or number ofcontact pin(s) is used, each contact pin may be arranged to be electrically conductive so as to provide electrical continuity between the clamped subsea object and the anode. Likewise, each contact pin may take any suitable shape or form, and may take the form of a screw. Each contact pin may have a cross-sectional shape of any suitable type, such as round, oval, or square. In many examples, a round cross section pin will be particularly practical.

[0095] In some examples wherein a plurality of contact pins are used, the tensioning unit is arranged to bias each ofthe contact pins towards the receiving space. In some examples, that may take the form of separate respective tensioning units for each ofthe contact pins, as with the four tensioning units 230, 231, 232, 233 shown in FIGS. 2 to 5 (although note that not all four tensioning units are shown in every gure).

[0096] The anode 200 shown in FIGS. 2 to 5 comprises four anodes 241, 242, 243, 244. However, in other examples, a different number of anodes may be used, including a single anode, or no anodes. As mentioned above, as used herein, the term anode refers to examples of an apparatus that comprises an anode itself (and thus can function as a standalone sacricial anode) and examples of an apparatus that does not comprise an anode but may be used to clamp to an anode or associated structure (such as cabling for an anode or anode sled) to a subsea object and / or structure. For example, the anode 200 may additionally or alternatively be used to clamp an external anode against a subsea object, with both the anode and the subsea object arranged in the receiving space 211. In such examples, having contact pins arranged on opposing sides ofthe receiving space 211 may be particularly benecial, because electrical contact may be made with a clamped anode on one side ofthe receiving space 211 and electrical contactmay be made with a clamped subsea object on the other side ofthe receiving space 211. In another example, the anode 200 may be used to clamp an anode sled or a cable ofan anode sled to a subsea obj ect.

[0097] Whichever arrangement or number ofanodes is used, in some examples, the anode comprises at least one of: a zinc based anode and / or an aluminium based anode. It will be understood that, for other examples, a different anode material may be used. In some examples, the anode is formed as a disc, as shown for the four anodes four anodes 241, 242, 243, 244 in FIGS. 2 to 5. In other words, one or more of at least one anode may have a disc-like shape or may be (at least substantially) disc shaped. In other examples, a different shape, such as a cube or sphere, may be used. In any implementation in which the anode disclosed herein comprises one or more anodes, each ofthe one or more anodes may be xed or coupled to the frame.

[0098] In some examples, the anode 200 further comprises an electrically conductive wire arranged to electrically couple the contact pin to the anode. The electrically conductive wire provides an electrically conductive pathbetween the contact pin and the anode, which in turn enables an electrically conductive path between the anode and the subsea object that the contact pin is in contact with. Examples of respective electrically conductive wires 251, 252, 253, 254 are shown in FIGS. 2 to 5 (although not every wire of the four wires is shown in every gure). Each of the electrically conductive wires 251, 252, 253, 254 shown connects a respective contact pin ofthe contact pins 220, 221, 222, 223 to a respective anode. However, it will be appreciated that in other examples, other arrangements may be used. For example, in some implementations, not every contact pin may use an electrically conductive wire to provide electrical coupling, and in some examples, more than one electrically conductive wire may be used between a particular contact pin and a particular anode in order to provide redundancy of connection. In some examples, an electrically conductive wire may not be used at all, and the anode may be formed such that the at least one contact pin is in electrical contact with an anode simply through using suitable electrically conductive xing structures and / or frames.

[0099] In some examples, the anode 200 comprises a rst anode being coupled to the frame on a rst side ofthe receiving space and a second anode being coupled to the frame on a second side ofthe receiving space, such as the anodes 242 and 243 in FIG. 2.

[0100] FIG. 4 shows the anode 200 of FIGS. 2 and 3 from another different perspective, which may be considered to be a side-view. In FIG. 4, a dashed line through the middle of the anode 200 is shown, marked from A to B. FIG. 5 shows a cross sectionview ofthe anode 200 ofFIGS. 2 to 5. The cross section view ofFIG. 5 corresponds to a cross-sectional plane taken along the dashed line fromA toB ofFIG. 4, that is, with the plane extending into and out ofthe page.

[0101] The anode 200 shown in FIGS. 2 to 5 also comprises a clamp adjustment mechanism 270, although it need not necessarily do so. The clamp adjustment mechanism is for tightening and / or loosening the frame around a subsea object to be clamped.

[0102] The clamp adjustment mechanism 270 ofFIGS. 2 to 5 comprises a handle 272 that may function as and / or be coupled to a torque connector. The handle 272 may be removeable. The handle 272 may be used by a human or robot operator to apply torque to the clamp adjustmentmechanism 270. The clamp adjustmentmechanism 270 also comprises a lead screw 271 comprising a threaded section extending between a distal and a proximal end. An example of a threaded section ofthe lead screw 271 is shown in FIG. 5.

[0103] In some examples, the clamp adjustment mechanism comprises a plastic bushing arranged around a threaded fastener (such as the lead screw 271), the threaded fastener being coupled to the frame for tightening and / or loosening the frame around a subsea object to be clamped. An exemplary plastic bushing 290 is shown in FIG. 2 as being arranged around the lead screw 271.

[0104] The clamp adjustment mechanism 270 also comprises a drive unit 260 arranged between the frame 210 and the torque connector and arranged to engage with the threaded section of the lead screw 271 such that rotation of the lead screw 271 results in movement of the drive unit 260 along the lead screw 271 in relation to the frame 210. The lead screw 271 itself is rotationally coupled to theframe 210 and the shape ofthe lead screw 271 longitudinally extends away from the drive unit 260 and towards and extending into the torque connector (corresponding to the handle 272 in the example of FIGS. 2 to 5) such that a torque can be applied to the lead screw 271. Furthermore, the drive unit 260 is coupled to the frame 210 such that relative movement between the frame 210 and the drive unit 260 in a rst direction causes the receiving space 211 at least partly dened by the frame 210 to widen, and relative movement between the frame 210 and the drive unit 260 in a second direction causes the receiving space 211 at least partly dened by the frame 210 to narrow. For example, in the implementation shown inFIGS. 2 to 5, turning the handle 272 applies atorque to the lead screw 271 that in turn moves the drive unit 260 relative to the frame 210 and effectively causes the rst and / or second arms 215, 216 to rotate on the hinge 217 in order to open or close the rst arm 215 and second arm 216 of the frame 210 about the receiving space 211, changing the effective size ofthe receiving space 211 and enabling the frame 210 to be clamped to an obj ect.

[0105] In this example, the slot 218 ofthe rst arm 215 ofthe frame 210 contains a drive pin 219 ofthe drive unit 260 and the second arm has a slot containing a corresponding second drive pin of the drive unit. This provides the coupling by which the drive unit 260 is coupled to the frame 210 such that relative movement between the frame 210 and the drive unit 260 in a rst direction causes the receiving space 21 1 at least partly dened by the frame 210 to widen, and relative movement between the frame 210 and the drive unit 260 in a second direction causes the receiving space 211 at least partly dened by the frame 210 to narrow. It will be understood that, in other examples, other suitable forms ofcoupling may be used.

[0106] Whichever arrangement is used, in some examples, the clamp adjustment mechanism is arranged to be operated by a remotely operated vehicle. The remotely operated vehicle may use a torque tool, which may be robotic, in order to apply torque to the clamp adjustment mechanism. Additionally or alternatively, the clamp adjustment mechanism may be operable by a human operator such as a diver.

[0107] FIG. 6 shows an example of a tensioning unit 230 according to the present disclosure. The tensioning unit 230 may be used in place ofany one or more ofthe tensioning units 230, 231, 232, 233 shown in FIGS. 2 to 5.

[0108] The tensioning unit 230 comprises at least one spring 610 arranged concentrically around the contact pin. In the example ofFIG. 6, the at least one spring 610 is a plurality of Belleville washers arranged around the contact pin such that the contact pin passes through a hole in the middle ofeach washer. Such an arrangement is also shown as the spring 501 in the example ofFIG. 5.

[0109] In this example, the tensioning unit 230 comprises a cover 620 or housing arranged to house at least a portion ofthe contact pin 220, the portion ofthe contact pin 220 comprising a protruded rim 630, the at least one spring 610 being arranged between an inner surface ofthe cover 620 and the protruded rim 630 to bias the contact pin 220 towards the receiving space.

[0110] As described elsewhere herein, the at least one spring 610 and thus tensioning unit 230 functions to bias or push the contact pin 220 towards the receiving space of the anode . In FIG. 6, a portion of a subsea object 650 is shown in the receiving space with the contact pin 220 penetrating the surface of the subsea object 650. Upon tightening of the anode around the subsea object 650, the at least one spring 610 is compressed, and the contact pin 220 is recessed within the cover 620. The at least one spring 610 is compressed between the surface of the cover 620 and the protruded rim 630 such that any relaxation ofthe at least one spring 610 will push the contact pin 220 towards and / or into the subsea object 650. Accordingly, ifthe contact pin 220 loses and / or reduces contact with the subsea object 650 due to environmental factors such as corrosion, the at least one spring will relax and push the contact pin 220 forwards, thereby maintaining electrical contact with the subsea object 650.

[0111] FIG. 7 shows an alternative example of a tensioning unit 230 according to the present disclosure. In the example of FIG. 7, components previously described elsewhere herein, such as the at least one spring 610, use the same reference signs as for their prior description.

[0112] In the example of FIG. 7, the contact pin 220 extends through an opening in the frame 210 towards the receiving space 211 and / or subsea object 650. The contact pin 220 comprises a protruded rim 720, the at least one spring 610 being arranged between a surface of the frame 210 and the protruded rim 720 to bias the contact pin 220 towards the receiving space. Accordingly, an analogous biasing effect to that described in relation to the cover 620 and protruded rim 630 ofFIG. 6 can additionally or alternatively be produced by arranging the spring between the frame 210 and the protruded rim 720. In this example, the contact pin 220 further comprises a second protruded rim 710 arranged on the other side of the frame 210 to the at least one spring 610 and the rst protruded rim 720. The second protruded rim 710 is wider than the space in the frame 210 through which the contact pin is arranged, and prevents the contact pin 220 from falling through or out ofthe frame 210 when the contact pin 220 is pushed or biased in the direction of the receiving space. It will be appreciated that in other examples an alternative shape ofcontact pin 220 or others means for preventing the contact pin 220 from passing entirely through the frame 210 may be used.

[0113] It will be understood that an anode may comprise one or more of the tensioning units ofFIGS. 6 and 7. For example, an anode may comprise two contact pins, one contact pin being biased by a tensioning unit like that ofFIG. 6, and the other being biased by a tensioning unit like that ofFIG. 7. In other examples, the anode may comprise two contact pins, each contact pin being biased either by a tensioning unit like that ofFIG. 6 or by a tensioning unit like that ofFIG. 7.

[0114] In other examples, the tensioning unit may comprise a pulling or tension spring rather than a compression spring like that of FIGS. 6 and 7, the pulling or tension spring being arranged to pull the contact pintowards the receiving space ofthe anode . Any suitable arrangement can be used to ensure that the spring or other tensioning means is arranged to bias the contact pin towards the receiving space.

[0115] Also disclosed herein is a cathodic protection system for a subsea structure, the cathodic protection system comprising an anode according to any one or more of the examples described herein. Also disclosed herein is a subsea structure comprising the anode ofany one or more ofthe examples described herein.

[0116] FIG. 8 shows a schematic diagram showing a method 800 ofusing an anode , according to the present disclosure. At a rst block 801, the method 800 comprises using the anode in a subsea cathodic protection system. Using the anode may comprise any one or more ofthe steps and / or functions described herein, such as c1amping the anode onto the subsea cathodic protection system by either a human or robotic operator.

[0117] The method ofFIG. 8, as well as all other methods disclosed herein, may in some implementations be performed autonomously, such as by one or more computing devices. The one or more computing devices may be part of, for example, a remotely operated vehicle for subsea operations.

[0118] The preceding detailed description is merely exemplary in nature and is not intended to limit the disclosure and its uses. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical eld, background, brief summary or the detailed description.

[0119] Examples ofthe present disclosure may be described herein in terms offunctional and / or logical block components and various processing steps. It should be appreciated that such block components may be realised by any number ofhardware, software, and / orrmware components congured to perform the specied functions. For example, an example of the present disclosure may employ various integrated circuit components, e.g., memory elements, digital signal processing elements, logic elements, look-up tables, or the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices. In addition, those skilled in the art will appreciate that examples of the present disclosure may be practised in conjunction with any number of systems, and that the systems described herein are merely exemplary embodiments ofthe present disclosure.

[0120] For the sake of brevity, conventional techniques compared to signal processing, data transmission, signalling, control and other functional aspects of the systems (and the individual operating components of the systems) may not be described in detail herein. Furthermore, the connecting lines shown in the various gures contained herein are intended to represent example functional relationships and / or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connection may be present in an example ofthe present disclosure.

[0121] Those skilled in the art will recognise that a wide variety of modications, alterations, and combinations can be made with respect to the above described examples without departing from the scope of the disclosed concepts, and that such modications, alterations, and combinations are to be viewed as being within the ambit of the disclosed concepts.

[0122] Further modications in addition to those described above may be made to the structures and techniques described herein without departing from the spirit and scope of the invention. Accordingly, although specic examples have been described, these are examples only and are not limiting upon the scope ofthe invention. 5

Claims

1. Anode clamp device for a submarine cathodic protection system, where the anode clamp device comprises the following: a frame, where the frame is designed to at least partially a to determine recording space for recording at least part of a submarine object to be clamped; at least one contact pin connected to the frame and configured to to protrude at least partially into the recording space, whereby the contact pin is electrical is conductive; and a tensioning unit connected to the contact pin, where the tensioning unit is configured to tension the contact pin towards the recording chamber.

2. Anode clamping device according to claim l, where the clamping unit has at least one encloses a spring arranged concentrically around the contact pin.

3. Anode clamping device within the meaning of claim 2, where at least one spring a Belleville ring is.

4. Anode clamping device within the meaning of claim 2 or 3, where the clamping unit is a includes a covering designed to cover at least a portion of the contact pin bring, whereby the part of the contact pin comprises a protruding edge, whereby the at least one spring between an inner surface of the covering and the protruding edge is configured to tension the contact pin towards the recording chamber.

5. Anode clamping device according to any preceding conclusion, where the contact pin arranged on the first side of two opposite sides of the recording room is and a second contact pin on a second side of the two opposite sides the recording room is equipped, whereby the second contact pin is electrically conductive.

6. Anode clamping device according to a preceding claim, where the contact pin is arranged on one side of the two opposite sides of the recording room and a second contact pin is arranged on the first side of the two opposite ones sides, where the second contact pin is electrically conductive.

7. Anode clamping device in accordance with any preceding conclusion, which further a Includes clamp adjustment mechanism for fastening and / or loosening the frame around an underwater object that needs to be clamped.

8. Anode clamping device within the meaning of claim 7, where the clamping adjustment mechanism comprises a plastic bushing that surrounds one of the threads provided fastener is arranged, whereby the threaded part fastener is coupled to the frame for fastening and / or detaching the frame around an underwater object that needs to be clamped.

9. Anode clamping device within the meaning of claim 7 or 8, where the clamp adjustment mechanism includes the following: a torque connector; a translation screw comprising a threaded section that is extends between a distal and a proximal end; and a drive unit arranged between the frame and the torque connector and is designed to engage with the threaded part provided part of the translation screw such that rotation of the translation screw in motion of the drive unit along the translation screw relative to the frame results in lead, where the translation screw is rotationally coupled to the frame and itself extend longitudinally away from the drive unit and towards and extend into the torque connector such that a torque can be applied to the translation screw, where the drive unit is coupled to the frame such that relative movement between the frame and the drive unit in a first direction brings about that the recording space, which is at least partially defined by the frame, expands and a relative movement between the frame and the drive unit in a second direction causes the recording space that is at least partially defined by the frame is, narrows.

10. Anode clamping device in accordance with claim 1, which further comprises an anode, optional where the anode comprises at least one of the following: a zinc-based anode and / or an aluminium-based anode.

11. Anode clamping device pursuant to claim 10, which is otherwise electrically conductive includes a wire designed to electrically connect the contact pin to the anode.

12. Anode clamping device according to one of claims 10 or 11, where the anode a is the first anode and the anode clamping device further comprises a second anode, where the first anode is coupled with the frame on a first side of the recording space and the second anode with the frame is coupled to a second side of the recording space.

13. Anode clamping device within the meaning of claim 12, where at least one contact pin comprises a multitude of contact pins and each of the first and the second anode is electrically coupled to a respective contact pin.

14. Subsea structure attaching the anode clamp device according to one of includes conclusions 1-13.

15. Procedure for using the anode clamp device according to one of conclusions 1-13, where the method involves the use of the anode clamping device in a includes submarine cathodic protection system.

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