BR102017001557A2 - device for the control of underwater scale biofouling - Google Patents

Abstract

A device (300) for controlling biofouling on subsea structures (6) is described, the device comprising a) set of cleaning rings (100) formed by at least three links (1), said rings (100) being provided with quick couplers (18) for connection with rope rings (110, 111) for scraping and cleaning of the undersea structure (6) and with the same number of loops (112) as the number of links (1), the set of rings (100) and rope rings (110, 111) yielding a semi-submersible ring (1000); b) hollow and hollow block assembly (2) provided with plug (20), the blocks (2) offering the float function (2000) when positioned close to the waterline; c) ballast assembly (2001) consisting of said blocks (2), the interior thereof containing a ballast of solid and dense material; and d) vertical ropes (5) for interconnecting between a), b) and c) and for transmitting the vertical movement to said device (300), and where to obtain the device of the invention it is mounted around the undersea structure ( 6), from top to bottom, a float assembly (2000), several semi-submersible cleaning assemblies (1000) at regular intervals and a ballast assembly (2001).

Description

DEVICE FOR THE CONTROL OF BIOINCRUSTATIONS IN SUBMARINE STRUCTURES FIELD OF THE INVENTION

[001] The present invention relates to a device for the control of biofouling in underwater structures, more specifically risers used for offshore oil exploration.

BACKGROUND OF THE INVENTION

[002] Currently oil extracted from the sub-oceanic layers (post-salt and pre-salt) is transported to the floating platforms by risers. The risers are basically very long tubes formed by several layers of different materials that allow the transport of oil in deep waters. A recurring problem with risers is the cleaning and scraping for inspection of this equipment, usually performed by specialized divers, this activity posing high risks to the life of these professionals.

[003] Certifying entities such as the National Petroleum Agency (ANP) require that periodic class inspections be performed on rigid flexible and rigid risers. For any type of inspection, it is necessary to remove marine fouling (barnacles) that form on the riser outer shell to gain access to the surface to be inspected. This inspection is performed by qualified divers and removal of the scale will end up making the process costly and time consuming and unhealthy for the diver performing the process. Scraping the risers further damages the coating, possibly compromising the operation of the component requiring replacement.

Preventive methods for reducing the growth of marine life on offshore platforms are known, which consist of applying layers of non-ferrous material (polymers) to bridge and pipe surfaces that eventually contain barnacle formation, reducing longitudinal and transverse stresses on the platform, as well as reducing corrosion of the surface part of the underwater structure. This procedure involves high financial value and ends up causing difficulties at the time of inspection.

[005] The patent literature presents several interesting documents concerning alternative mechanical systems for the control of biofouling in subsea structures.

Utility patent application MUBR2020150046419, by the same inventors and incorporated herein in full by reference, describes a structure consisting of semi-submersibles and submersibles, brushes or brooms on the inside of each float and wire ropes and ropes or bars. which have the function of linking between the buoys. In the proposed solution, steel cables, ropes or bars will be responsible for the transmission of vertical movement between the different buoys at different depths. The solution in question also features an articulated joint for fixing the steel cables, ropes or bars, which are mounted by mechanical interference to the structure of the float.

[007] The various semi-submersible and submersible floats are mounted in the form of rings around the riser, equally spaced apart by said cables, ropes or bars. The distance between the floats will be equal to or less than the average amplitude of the wave undulation height in the region in which the tool is installed. Preferably, the distance at which the buoys are arranged ranges from 1.0m to 2.0m, even more preferably, this distance is 1.5m. The buoys will be mounted to the depth where the barnacle surface rises.

With respect to the Utility Model mentioned above in this report, the rings are bipartite systems, which requires that for each different outside diameter of riser to be cleaned, a single bipartite ring must be manufactured. The above model describes a broom or brush cleaning system, but these components that have been rubbing against the riser for a long time show very high wear, causing the brush bristles to detach, shortening the life of the equipment. Also, the connections between the rings, being made through bars or steel cables, have the disadvantage that, since they are metallic materials, even when they are stainless, they have limited life in marine environments. Moreover, this utility model deals with semi-submersible systems, which requires strict control of the mass, volume and consequent density of the materials employed, making the assembly and stability of the set in operation difficult.

U.S.5026212 describes an equipment for removing scale from marine structures, the equipment comprising multicomponent floating rings and submerged rings adapted to surround a structural member supporting the marine structure. The equipment is moved by the use of ocean forces in the form of waves, ripples, tides and currents such that marine fouling is removed from the structural support member by reciprocal movement of the equipment around the structural support member. This document differs from the present invention in that the cleaning process performed corresponds to scraping the duct surface through metal brushes. Rubbing metal brushes on a surface causes damage to the surface, such as scratches and surface wear. In pipelines with metallic surfaces, damage is mainly caused to the external paint of the pipe, exposing the metal to marine water and encouraging corrosive processes. For surfaces coated with polymeric layers, such as risers, there is wear on the coating material, shortening the life of the pipe and causing environmental pollution as the residue from scraping the steel brush to the polymer covering the duct is thrown. to the marine environment.

In US 5040923 an equipment for removing scale from marine structures is claimed, the equipment comprising at least one brushed ring including a plurality of roller brushes combined to form a biofouling prevention collar, each roller brush being able to rotate freely about a brush axis and being able to move freely along said axis; the bristles of said roller brush being adapted to surround the marine structure. This document differs from the present invention in that it has rotating bristle brushes attached to an axis for cleaning. Brushes have a shortened life because after a short period of time their bristles detach. Also, this equipment has several moving parts, for example, the fact that the brush needs to rotate under an axis. The marine environment causes these movements to stop over time because of debris that tends to stick to surfaces. Thus, the useful life of the equipment is reduced and at the same time gives the need for constant preventive maintenance for the proper functioning of the parts.

U.S. Patent 5,765,968 relates to wave, current or tidal powered equipment for eliminating or preventing marine biofouling on a structure. The equipment includes a) at least one ring adapted to surround a submerged frame support member, said ring being substantially continuous; b) at least one pair of rollers rotating against a surface of the support member to clean the surface thereof; and c) a connecting member for joining the roll to the ring without disrupting the continuity of the substantially continuous ring and to allow rotation of the rollers against the support surface in reaction to wave, current or tidal forces. This document differs from the present invention in that it uses bristle roller shaped brushes. The equipment also needs two types of relative movement in relation to the duct: vertical oscillation provided with the movement of the waves and the rotation around the pipe. For the latter movement, the equipment is provided with hydrodynamic elements to cause rotation as water movement passes through the region. Also, like the previous equipment, this equipment has several moving parts, such as the rotation of the brushes under one axis. The marine environment causes these movements to stall over time by depositing debris that tends to stick to surfaces. Thus, the useful life of the equipment is reduced and at the same time gives the need for constant preventive maintenance for the proper functioning of the parts. Still, the use of brushes is not interesting due to the fact that these devices have a reduced useful life due to detachment of their bristles over time.

[012] U.S.7222578 discloses apparatus for removing marine biofouling from a submerged structure and preventing future deposits. The equipment floats on the surface of the water or under water and with the help of natural force repeatedly collides with the surface of the structure to remove biofouling deposited on it. The apparatus has a first rope around the surface of the structure at water surface level and at least one or more rotatable elements connected to this first rope and freely rotating around the rope. The rotating elements collide with the surface of the structure when the equipment floats on the water surface or is submerged, eliminating deposits on the structure and preventing additional deposits from being deposited. This document differs from the present invention in that there are a large number of moving parts that necessarily need to rotate around the rope for cleaning. Also, the fact that these equipment impact on the surface of the duct to clean it decreases the useful life of the equipment, because in periods of storm at sea this impact against the surface is very aggressive and may cause the components to break. Still, the breaking of its parts and consequent release to the marine environment causes environmental pollution in the region.

[013] U.S. published patent application US 20030005874 deals with equipment for removing marine organisms and the like from an underwater surface by floating equipment close to said surface and causing the equipment to repeatedly collide with said surface, the apparatus comprising a plurality of pivotally connected bodies in a series, each body having an outer surface with an annular portion and an associated protective cap, the annular portion of the outer surface of each body being encircled by its associated protective cap. This document differs from the present invention in that there are a plurality of moving parts that make up the equipment, making its manufacture, assembly and installation very complex. Still, there are a number of moving parts that necessarily need to rotate around their structure for cleaning. Added to the fact that these equipment must impact on the surface of the duct to perform cleaning, which reduces the life of the equipment, because in marine storms the impact against the surface is very aggressive, which can cause the components to break. The breaking of its parts and consequent release to the marine environment causes environmental pollution in the region.

[014] International publication W02008123761 is about durable marine biofouling control equipment to be installed around structural marine components, the equipment comprising a plurality of rollers disposed on a plurality of shafts, a plurality of connectors joining the shafts to forming a ring and a plurality of fins mounted at the other end of said connectors, the apparatus being characterized in that the connector is a 3-point connector. This document differs from the present invention in that there are a large number of moving parts in its configuration, making its manufacture, assembly and installation very complex. Also, moving parts necessarily have to rotate around their structure to clean. The equipment also needs rotation around the pipe, movement provided to the equipment by hydrodynamic wings to cause rotation as water movement passes through the region. Yet these salient hydrodynamic structures have volume that makes them susceptible to impacts and breaks caused by objects moving in the region.

[015] US Published Application US 2014/0130273 A1 consists of a rubber roller ring cleaning system that uses tidal movement to propel the device. The equipment object of this patent document has a limited use time with premature breakage of the connectors, being difficult to maintain components.

SUMMARY OF THE INVENTION

[016] The proposed device for control of biofouling in subsea structures and intended for enclosing a floating or submerged structure is comprised of: a) set of cleaning rings (100) formed by at least three links (1), said rings (100 ) having quick couplers (18) for connection with rope rings (110, 111) for scraping and cleaning of the undersea structure (6) and with the same number of loops (112) as the number of links (1 ), the set of rings (100) and rope rings giving rise to a semi-submersible ring (1000); b) hollow and hollow block assembly (2) provided with plug (20), the blocks (2) offering the float function (2000) when positioned close to the waterline; c) ballast assembly (2001) consisting of said blocks (2), the interior thereof containing a ballast of concrete or other dense solid material; and d) vertical strings (5) for interconnecting between a), b) and c), said strings (5) being responsible for transmitting the vertical movement to said device (300), and where to obtain the device of the invention is mounted , around the subsea structure (6), from top to bottom, a float assembly (2000), several semi-submersible cleaning assemblies (1000) at regular intervals and a ballast assembly (2001).

[017] Links are structures made of engineering material preferably inert to the marine environment, such as engineering plastic. The cleaning rings consist of the assembly of several links with quick couplings. In this way it is possible to assemble rings with different number of links for different riser diameters (or any other cylindrical marine structures) to be cleaned. In addition, each link has hooks to which ring-shaped ropes intertwine. Useful for the invention are rope rings made from polyester rope. This rope ring is made up of several rope loops formed on each of the hooks of each link mounted on the ring, and closed by knot between the ends of the rope. The number of loops in the rope corresponds to the same number of links that form the ring. On top of a ring, rope rings are mounted on the upper and lower face of the ring. The configuration of the tie-down of the rope rings over the link ring allows only the rope to have contact with the clean duct surface, thus allowing, in the vertical oscillation of the entire device, the scraping by this rope to perform the desired cleaning.

[018] Each float is a kind of enclosed box or block with a cap on the upper side and performs the function of a float when the cap on the upper side is closed while keeping air inside; It is possible to keep a certain amount of water in the float to decrease the positive buoyancy when the float is to be submerged in the water.

[019] Each ballast is a buoy-like structure, but with the top cover kept open allowing the box to be flooded with water, still filling it with counterweights (such as concrete). The amount of counterweight required varies with the total size of the set, being approximately 5 kg without being limited to this weight.

[020] A float or ballast assembly is mounted by securing the float or ballast between two cleaning rings. The joining between the rings and the floats or ballasts is through a vertical rope, and the floats or ballasts are fitted into the links of the cleaning rings in a T-shaped recess.

The device of the invention for controlling biofouling in subsea structures is assembled in the following sequence: float assembly at the top of said structure, a series of cleaning ring assemblies at the middle, and a ballast assembly at the bottom. . The distance between each set of wiping rings must be equal to or less than the average amplitude of ocean wave ripple in the operating region of the device. The amount of cleaning ring assemblies to be used depends on the depth of reach of sunlight, since the formation of biofouling depends on the presence of sunlight on the site.

[022] The device of the invention when mounted on a pipeline in the ocean works as follows: the buoy set holds the system in the waterline due to its positive thrust (vertical upward force). Already the ballast keeps the system intended due to its weight (vertical downward force). It is important that the buoy thrust is always greater than the counterweight so as not to unbalance the system.

[023] The ripple of the waves will cause the system to rise and fall due to buoyant buoyancy, causing the whole system to rise and fall at the same time. Thus, with relative vertical movement between the device and the riser, there will be friction between the cleaning ropes and the riser, thus preventing the emergence of biofouling on the outer surface of the underwater structure.

BRIEF DESCRIPTION OF DRAWINGS

The attached FIGURE 1 illustrates a link according to the invention. FIGURE 1A shows the top view, FIGURE 1B the front view and FIGURE 1C isometric view of a representative link of the concept of the invention.

The attached FIGURE 2 illustrates a float according to the invention, the float being provided with threaded hole and plug.

The attached FIGURE 3A illustrates five individual links as illustrated in Figure 1 while the attached FIGURE 3B shows the set of five links connected to form a ring according to the invention.

The attached FIGURE 4A illustrates an upper rope ring for cleaning the outer wall of the underwater structure. The attached FIGURE 4B illustrates an upper rope ring. The attached FIGURE 4C illustrates a ring assembled from the links of Figure 1 and within the ring, the rope rings for cleaning the subsea structure.

The attached FIGURE 5A illustrates a float assembly as shown in Figure 2. The attached FIGURE 5B illustrates the float assembly with the link ring and rope ring assembly for cleaning the subsea structure.

The attached FIGURE 6 represents the form of mooring of a vertical rope in each of the links according to the invention.

The accompanying FIGURE 7 depicts one embodiment of the device of the invention mounted around an undersea duct-shaped structure.

DETAILED DESCRIPTION OF THE INVENTION

[031] In order to remedy the shortcomings of the current state of the art highlighted above, the present application aims to propose a solution to the main problem of formation of marine barnacles that adhere to the outer cover of various types of underwater structures, among them the oil rig risers. Thus, in this report, the term "risers" should be taken as a specific case representing any and all similar structures present in the marine environment to which the principle of the invention can be applied.

After being installed in platform risers the tool presented in the invention has as main constructive advantage the fact that it is not necessary to perform the cleaning of the pipes for subsequent biennial mandatory inspection, since the use of said tool or device proposed here prevents marine crustaceans from forming on the surface of risers.

[033] The invention will be described hereinafter by reference to the accompanying Figures, which are not to be construed as limiting thereof.

[034] The invention comprises a device for controlling biofouling in underwater structures, including underwater platform risers, the device generally being designated by numeral (300).

As explained above in this report, the device 300, to be installed around underwater structures, e.g. risers 6, comprises rings, generally designated by numeral 100, consisting of assemblies of at least 3 links (1). The links (1) can be seen in FIGURE 1, with FIGURE 1A being the top view of a link (1), FIGURE 1B being the front view of said link (1) and FIGURE 1C being the isometric view thereof. A link (1) is a part composed of two semi-cylindrical sides: to the right of FIGURE 1A, the semi-cylindrical side being central to the body, or positive (11), and is provided with protruding pins (18); and to the left of the same FIGURE 1A, the side is cast in the center of the link (1), or negative (10), and is provided with latches (15) that lock the protruding stud (18) from other links (1) when docked. These semi-cylindrical sides are joined using a T-shaped plastic structure (14) at the top and a horizontal plastic structure at the bottom (17) of the link (1).

[036] When the link ring (100) (1) is mounted on the undersea structure, such as a riser (6), the T-frame (14) of the links (1) will be on the outside of the ring. (100), farthest from the undersea structure, and the horizontal structure (17) of the links (1) will be in the inner part of the ring (100), closest to the undersea structure (6).

[037] The link (1) is provided with two hooks (12), one at the top and one at the bottom of the piece, with the function of securing the loops (112) of the upper ring (110) of the cleaning rope ( 113) and the lower ring (111) of the cleaning rope (113).

[038] In addition, there is a vertical hook (13) on the link (1), with a vertical rope winding function (5), and a lock (16) that prevents the vertical rope from unwinding (5) when said rope (5) is mounted to the vertical hook (13).

[039] The semi-cylindrical lateral central to the body of the link (1) or positive (11) has radial structures with structural reinforcement function, having no practical function in the operation of the described set.

[040] Already the hollow side to the center of the link (1), or negative (10) presents cylindrical recess, and is a material injection point in its manufacture, having no practical function in the operation of the described set.

[041] The assembly of the ring (100) can be seen in FIGURE 3, where FIGURE 3A illustrates five links (1) before being combined into one ring (100). The ring (100) comprises the two link fittings ( 1), namely the negative semi-cylindrical lateral (10) and the positive semi-cylindrical lateral (11). To assemble a ring (100) shown in FIGURE 3B, the desired number of links (1) is combined by the positive socket (11) of one link (1) mounted in the negative socket (10) of another link (1). 1) securing the pin (18) through the lock (15). It will be clear to those skilled in the art that the embodiment illustrated in FIGURES 3A and 3B is given merely by way of Example, other embodiments and embodiments being possible and equally fully understood in the concept of the invention.

[042] The assembly of a cleaning rope upper ring (110) (113) and cleaning rope lower ring (111) (113) can be seen in FIGURE 4. Two hooks (12), one upper and one other lower links (1) are used for winding the upper ring (110) of cleaning ropes (113) and the lower ring (111) of cleaning ropes (113) through the loops (112) of said ropes. For forming the loops 112, two or three turns of the rope will be made to make sufficient clearance between the ring 100 and the surface of the undersea structure, for example the riser 6. The protruding parts of the cleaning ropes (113) are responsible for scraping and consequent cleaning of the underwater structure, for example the riser (6). The cleaning rope (113) is terminated by knot (114) at the ends thereof. Thus is formed the cleaning assembly (1000), consisting of a ring (100) with five links (1) (not limited to this number) and the respective upper (110) and lower (111) rings of strings cleaning (113).

[043] The mounting of the vertical ropes (5) can be seen in FIGURE 6. The vertical ropes (5) are mounted on the links (1) cylindrically engaging the vertical hook (13) and locking in the lock fitting (16). The number of vertical ropes (5) in the assembly assembly is the same as the number of links (1) forming the ring (100). The vertical ropes (5) have the function of joining several rings (100) at predefined distances, as seen in the general assembly of the device (300) of the invention illustrated in FIGURE 7. Both rope rings (110, 111) The cleaning straps (113) and the vertical strings (5) are preferably made of a synthetic material of great durability and resistance to friction, including polymers, mainly as a polyester.

[044] In FIGURE 2 the block (2) is displayed. Useful for making the block (2) is an engineering plastic, inert to the marine environment. The block (2) is hollow and is provided with a screw cap (20) on its upper face, used to close the block (2), avoiding water flooding when necessary. The block (2) is further provided with a hollow T-shaped recess (21) at the top and another bottom recess (22). The recesses (21, 22) fit into the T-shaped structure ( 14) of the link (1).

[045] The float assembly (2000) or ballast (2001) can be seen in FIGURE 5. The assembly is mounted with the fitting of the hollow T-shaped recesses in the upper (21) and lower (22) of the block (2) to the T-shaped structures (14) of the links (1) forming the ring (100).

[046] Block (2) can provide float function (2000) when plug (20) is threaded, keeping block (2) tightly closed, or ballast function (2001) when filling part of block (2) counterweighted with concrete or other solid material and block (2) without a plug (20) is maintained, allowing water to enter.

[047] FIGURE 7 depicts the device of the invention (300) as mounted on, but not limited to, a duct-shaped undersea structure (6) selected from a pier. Around the subsea structure (6) to be cleaned is mounted, from top to bottom, a float assembly (2000), several cleaning assemblies (1000) and a ballast assembly (2001).

[048] The top float assembly (2000), when mounted to the undersea structure as a ripper (6), will be at the seawater line, while the rest of the device (300) will be submerged due to the pull of the ballast (2001) at the bottom. The connection between these elements is given by said vertical strings (5). The amount and distance of the cleaning assemblies (1000) depends on the depth at which it is desired to keep free of biofouling and / or cleaning the duct or ridge (6), and on the average wave ripple oscillation height in the region where the device (300) of the invention is installed.

Claims (14)

1. DEVICE FOR CONTROLING BIOINCRUSTATIONS IN UNDERWATER STRUCTURES, said device comprising: a) set of cleaning rings (100), the rings (100) being formed by at least three links (1), said rings (100 ) being provided with quick couplings (18) for connection with rope rings (110, 111) for scraping and cleaning of the undersea structure (6), said rings (110, 111) having the same number of loops (112). ) that the number of links (1), the set of rings (100) and rope rings (110, 111) giving rise to a semi-submersible ring (1000); b) hollow and hollow block assembly (2) provided with plug (20), the blocks (2) offering the float function (2000) when positioned close to the waterline; c) ballast assembly (2001) consisting of said blocks (2), the interior thereof containing a ballast of concrete or other dense solid material; and d) vertical strings (5) for interconnecting between a), b) and c), said strings (5) being responsible for transmitting vertical movement to said device (300), and where to obtain said device (300) is mounted around the subsea structure (6) from above, a float assembly (2000), several semi-submersible cleaning assemblies (1000) at regular intervals along the subsea structure (6) and a ballast assembly (2001 ). Device according to claim 1, characterized in that the link (1) comprises: a) two semi-cylindrical sides, one central side to the body of the link (1), or positive (11) provided with protruding pins (18), other side being cast to the center of the link (1), or negative (10), and provided with latches (15) to lock the fitting of corresponding pins (18) of another link (1) when engaged, the union of said semi-cylindrical sides being made with the aid of a T-shaped plastic structure (14) at the top of the link (1) and a horizontal plastic structure at the bottom (17) of said link (1); b) two hooks (12), one at the top and one at the bottom of the link (1), for securing the upper (110) and lower (111) ring loops (111) of the cleaning rope (113) ; and c) a vertical hook (13) for winding vertical ropes (5) and a lock (16) to prevent unwinding of said vertical rope (5) when said rope (5) is mounted to said vertical hook (13). . Device according to Claim 1, characterized in that the assembly of the ring (100) from links (1) comprises engaging the positive socket (11) of one link (1) in the negative socket (10) of another. link (1) securing the pin (18) through the lock (15). Device according to Claim 3, characterized in that the ring (100) comprises five links (1). Device according to claim 1, characterized in that the cleaning assembly (1000) is formed from the assembly of an upper ring (110) of cleaning ropes (113) and lower ring (111) of cleaning ropes (1). 113) with the aid of two hooks (12) of the link (1) for winding the upper ring (110) of cleaning ropes (113) and the lower ring (111) of cleaning ropes (113) through the loops (112 ) of said strings. Device according to Claim 1, characterized in that the cleaning rope (113) is terminated by means of a knot (114) at the ends thereof. Device according to Claim 1, characterized in that, to join the various rings (100) positioned along the undersea structure (6) at predefined distances, the vertical ropes (5) are mounted on the links (1) surrounding cylindrically the vertical hook (13) and locking in the locking socket (16). Device according to claim 7, characterized in that the number of vertical ropes (5) in the assembly of the assembly is the same as the number of links (1) forming the ring (100). Device according to Claim 1, characterized in that the block (2) is: (a) hollow and provided with a screw cap (20) on the upper face thereof; and (b) provided with a hollow recess (21) in T-shape at the top and another recess (22) in the bottom, the recesses (21, 22) fitting into the T-shaped structure (14) of the link. (1). Device according to claim 1, characterized in that the float assembly (2000) or ballast (2001) is mounted with the fitting of the hollow T-shaped recesses in the upper (21) and lower (22) of the block (2) to the T-shaped structures (14) of the links (1) forming the ring (100). Device according to claim 1, characterized in that the block (2) performs the float function (2000). Device according to Claim 1, characterized in that the block (2) alternatively performs the function of ballast (2001) when part of the block (2) is filled with counterweights, the block (2) being maintained without a plug (20). to allow water to enter. Device according to Claims 1 to 12, characterized in that the underwater structure is a duct. Device according to Claim 13, characterized in that the duct is a riser.