MAGNETIC ANTI-SCALE DEVICE

Abstract

The present invention relates to a magnetic antifouling device attachable around pipes with fluid flow inside, comprising an outer pipe; and a plurality of magnetic arrangements, where each magnetic arrangement comprises a cylindrical support and a plurality of magnets arranged circumferentially on the cylindrical support; the plurality of magnetic arrangements comprising a sequence of magnetic arrangements arranged side by side is attached longitudinally around the pipe in an axisymmetric arrangement, forming at least one plane of concentration of the magnetic field; at each end of the axisymmetric arrangement a spacer and a damper are placed, and the outer pipe surrounds the axisymmetric arrangement.Applying a high density of magnetic flux orthogonal to the velocity of the fluid being treated inhibits the formation of scale on the inner wall of pipes and reduces scale buildup in upstream equipment.

Description

MAGNETIC ANTIFOULING DEVICE SCOPE

[001] The present invention relates to a tubular device and equipment that, by concentrating the magnetic flux within its interior, raising the magnetic flux density to an adequate level, inhibits the formation of scale on the inner wall of pipes and reduces scale on equipment (valves, connections, etc.) located upstream. The device described herein can be installed in any pipeline used to transport fluids, including underwater oil well pipelines. These fluids can be oils, lubricants, gases, vapors, water, petroleum or liquids in general. Description of the State of the Art

[002] Scale is a common problem in many industries, being very present in equipment where pressure and / or temperature are not constant, such as heat exchangers, valves, boilers and cooling towers. Problems related to scale formation also affect the oil and gas industry, mainly in pipelines used for oil extraction, requiring interventions in the wells, generating recurring shutdowns and, consequently, causing high costs. Traditional strategies to prevent scale formation consist of the continuous injection of chemicals, many of them high cost, environmental impact and often of limited effectiveness. Therefore, alternatives for scale prevention have been sought. One strategy for this is the use of magnetic devices.

[003] Magnetic treatment is an interesting alternative to combat scaling, especially when using magnetic 239125 2086706 of 17 permanent magnets as sources of magnetic flux. This technology has the advantage of being passive, meaning it does not require activation by either electrical energy or hydraulic pressure.

[004] Prior art document PI0901552-3 also describes a magneto-hydrodynamic device for combating the deposition of inorganic solid minerals that form deposits and scale in oil columns. However, it is an invasive device, the fluid passes between the magnets, which makes its application in the oil industry limited (e.g., in deep water). Furthermore, invasive devices can reduce fluid flow. One of the advantages of the device of the present invention with respect to its use in the oil industry is the fact that it is non-invasive, allowing its use in harsh, hard-to-reach environments without reducing oil flow.

[005] The device of patent PI 1104037-8 aims to promote a magnetic field inside the pipe through which a certain fluid circulates. To achieve this, magnets are placed around an existing pipe. In addition to requiring an unusual installation process and increasing the outer diameter of the pipe, the use of these devices in the oil sector faces another major problem. Most of the pipes in the oil industry are made of ferromagnetic materials, which reduces or eliminates the intensity of the magnetic field generated inside the pipe and, therefore, also reduces or eliminates the effectiveness of the treatment. In contrast, the device of the present invention can be used as an integral part of the production column (or the fluid pipeline) without affecting the usual installation procedure.In addition, the device is made of a material that does not reduce the magnetic field generated by the magnets. 239125 2086706 of 17

[006] Patent PI 1003774-8 also describes improvements in anti-fouling magnetic devices for fluid transport pipelines. However, little is described about the mechanical refinements of the device that provide robustness to the system. Rather, the present invention details the mechanical arrangement that allows the positioning of the magnets and increases the robustness of the system for application in high pressure and temperature environments (such as offshore oil wells). Furthermore, the present invention also provides different possible magnetic arrangements to be used in the device, allowing the concentration of the magnetic field not only in the central section, but also in several sections along the device.

[007] Although various magnetic devices for inhibiting scale formation inside pipelines are known, there is no suitable system in the state of the art for applying this treatment to prevent scale formation in underwater pipelines in the oil sector. The present invention relates to a passive, non-invasive magnetic device that can be installed as an integral part of the production column.

[008] The device presented and described here has the unprecedented use of an axisymmetric topology, which allows its installation on the walls of the pipe, and uses a magnetic flux concentration topology that allows reaching higher levels of magnetic flux density inside the pipe through which the fluid to be treated passes. Objectives of the Invention

[009] A first object of the invention is to provide a tubular device and equipment capable, by generating a high level of magnetic flux density, of inhibiting the formation of scale on the inner wall of pipes. The device described herein can 239125 2086706 of 17 can be installed on any pipeline used to transport fluids, including subsea oil well pipelines. These fluids can be oils, lubricants, gases, vapors, water, petroleum, or liquids in general. Brief Description of the Invention

[010] The objectives of the invention are achieved by an anti-fouling magnetic device comprising an axisymmetric magnetic arrangement confined between a non-ferromagnetic inner tube with fluid flow therein, an outer tube arranged concentrically to the inner tube, and two diameter transition elements, each at one end of the outer and inner tubes; wherein the magnetic arrangement comprises at least one arrangement section comprising a plurality of permanent magnets arranged circumferentially on a non-ferromagnetic cylindrical support; wherein the magnetic arrangement has at least one magnetic flux density concentration plane with a direction perpendicular to the fluid flow.

[011] The inner tube has an outer diameter (OD) smaller than the inner diameter (ID) of the cylindrical supports of the magnetic installations, so that the cylindrical supports fit the outside of this inner tube.

[012] The outer tube is a tube concentric to the inner tube, but with an inner diameter (ID) larger than the outer diameter (OD) of the inner tube, such that the difference between the ID of the outer tube and the OD of the inner tube is sufficient to allow accommodation of the magnetic installations. Therefore, the inner diameter (ID) of the outer tube is larger than the outer diameter (OD) of the cylindrical supports of the magnetic installations. The outer pipe may have pressure equalization openings which may be in the form of 239125 2086706 of 17 round holes, slots, windows, or any shape that allows pressure equalization. The inner and outer tubes and diameter transition elements (e.g., cross connections) are made of a material having a relative magnetic permeability less than or close to 1, preferably between 0.99 and 1.01. In addition, the inner and outer tubes and diameter transition elements are made of Nickel Alloys (Inconel 718, 625), Aluminum Alloys, Austenitic Steels, Duplex Steels, or Super Duplex Steels.

[013] Preferably, the inner and outer tubes and diameter transition elements are made of Inconel 718.

[014] The anti-fouling magnetic device may comprise at least one damper in the confined space between the inner tubular element, the outer tubular element and the two diameter transition elements. The anti-fouling magnetic device may also include at least one spacer in the confined space between the inner tubular element, the outer tubular element and the two diameter transition elements. Preferably there is a spacer and a damper on each side of the magnetic arrangement, but a single damper may be used in the device, which is not necessarily arranged at its end. Preferably, the spacers are arranged between the magnet holders and the damper. The spacers are preferably manufactured from nitrile rubber.

[015] The magnets used are of the high energy magnet type, which have a suitable and constant magnetic field and are confined between the external wall of the tube with fluid flow inside and the internal wall of the external tube, in an axisymmetric topology that allows the concentration of the magnetic flux inside the internal tube. 239125 2086706 of 17 ferably, the magnets arranged in the magnetic arrangement are permanent NdFeB magnets.

[016] The novel magnetic arrangement developed for the device of the present invention allows to reach higher levels of magnetic flux density inside the inner tube and, therefore, makes the magnetic treatment viable and increases its effectiveness.

[017] The axisymmetric arrangement may comprise at least one perpendicular magnetic arrangement section with magnets whose magnetic poles are oriented perpendicularly to the wall of the pipe with fluid flow therein, and at least one parallel magnetic arrangement section with magnets whose magnetic poles are oriented parallel to the wall of the pipe with fluid flow therein.

[018] The perpendicular magnetic arrangement section comprises a first segment containing half of the magnets, where all the poles are oriented in the centripetal direction, and a second segment containing the other half of the magnets, where all the poles are oriented in the centrifugal direction. The parallel magnetic arrangement section comprises a first segment containing half of the magnets, where all the poles are oriented in a first direction parallel to the pipe and in the same direction as the fluid flow, and a second segment containing the other half of the magnets, where all the poles are oriented in a second direction opposite to the first, and in these always parallel to the pipe.

[019] According to the invention, the axisymmetric arrangement may comprise a plurality of perpendicular magnetic arrangement sections and a plurality of parallel magnetic arrangement sections arranged alternately with each other, in which the two ends 239125 2086706 of 17 are arranged in parallel.

[020] According to another embodiment of the invention, the axisymmetric arrangement comprises a plurality of perpendicular magnetic arrangement sections and a plurality of parallel magnetic arrangement sections arranged alternately with each other, wherein perpendicular magnetic arrangement sections are arranged at both ends of the axisymmetric arrangement.

[021] In the axisymmetric arrangement, the perpendicular magnetic arrangements may be arranged alternately with pole orientations in opposite directions, and the parallel magnetic arrangements may be arranged alternately with pole orientations in opposite directions.

[022] In the embodiments of the invention in which sections of perpendicular magnetic arrangement alternating with sections of parallel arrangement are used, several magnetic field concentration planes are formed, one in each region corresponding to a perpendicular arrangement.

[023] In yet another embodiment of the invention, the axisymmetric arrangement comprises one or more perpendicular magnetic arrangement sections in the central portion, and a plurality of parallel magnetic arrangement sections arranged on either side of at least one central perpendicular magnetic arrangement section, wherein adjacent parallel magnetic arrangement sections have the same pole orientation. In this mode, the formed magnetic field concentration plane exhibits a higher magnetic concentration in the central portion than in the previously described modes.

[024] Connectors are also used, which consist of any element intended to join the ends of the pipe segment where 239125 2086706 of 17 connects the Magnetic Antifouling Device to the rest of the piping in the system where the device will be installed, allowing the fluid to be treated to pass through the magnetic flux concentration region. Examples of possible connectors include flanges, crossovers, threaded connections, and welded connections. Therefore, it is not necessary to use welded connections inside the antifouling device, which simplifies its installation in the pipes. The elimination of welded connections improves the performance of the antifouling device, as welds can impair the operation of the magnets.

[025] The device may further comprise at least one wiring protection mechanism arranged at least on the outer tube and / or on at least one of the diameter transition elements. Brief Description of the Figures

[026] For a better understanding, the features and advantages of the present invention will be presented and described together with their respective figures, which illustrate some preferred embodiments of the invention.

[027] Figure 1 shows a perspective view of the cross section of the magnetic device according to one embodiment of the invention.

[028] Figure 2 represents an exploded perspective view of the sections of the magnetic arrangement used in the arrangement of the magnetic device according to Figure 1.

[029] Figure 3 represents an exploded perspective view of the sections of the magnetic arrangement used in the arrangement of the magnetic device according to Figure 1 with arrows identifying the magnetic flux generated by these sections of the magnetic arrangement showing the Flux Concentration Effect. 239125 2086706 of 17 Magnetic

[030] Figure 4 shows a perspective view of the cross-section of the magnetic device with a magnetic arrangement mode according to the invention with a magnetic concentration plane.

[031] Figure 5 shows a side view of the cross-section of the magnetic device with a magnetic arrangement mode according to the invention with three magnetic concentration planes.

[032] Figure 6 shows a side view of the cross-section of the magnetic device with a magnetic arrangement mode according to the invention with four magnetic concentration planes.

[033] Figure 7 shows a side view of the magnetic device with pressure compensation openings.

[034] Figure 8 shows a side view of the magnetic device with cable protection mechanisms arranged on the outer tube. Detailed Description of the Invention

[035] Figure 1 illustrates a preferred embodiment of the magnetic anti-fouling device, object of the present invention patent. The device comprises a magnetic arrangement 10, confined between the outer wall of at least one inner tube with fluid flow inside 20 and the inner wall of an outer tube 30. Each end of the pipe segment having fluid flow inside 20 in which the magnetic anti-fouling device is located further comprises a transition element of diameter 40 that is adapted to connect said magnetic device to the pipes.

[036] The outer tube 30 protects the magnetic arrangement from lateral impacts and wear during movement, installation and use of the device. For applications of the device in regions of 239125 2086706 of 17 high external pressure, the outer tube 30 may contain a plurality of openings 31 distributed axially and radially to allow equalization of the external and internal pressures, as illustrated in Figure 7. The openings may be in the form of round holes, slots, windows or any other shape that allows pressure equalization. This equalization reduces the risk of collapse of the outer tube 30 and, therefore, of damage to the magnetic arrangement 40.

[037] Figure 1 also shows the diameter transition elements 40 at each end of the device according to a preferred embodiment of the invention. In this case, the diameter transition elements 40 used were crossovers. One end of the crossover is joined to the fluid-flowing pipe segment 20 through a threaded connection (previously machined) or by welding, and the other end has a compatible diameter to be joined to the rest of the pipe through a threaded connection or welding. Transition elements of other diameters, such as flanges and couplings (couplings, elbows, unions), can also be used. Although it is necessary to use welds at the ends of the diameter transition elements for coupling to the rest of the pipe, these welds are kept away from the magnets used in the anti-fouling device, thus preventing them from interfering with the magnetic effects of these magnets.No welding is used inside the antifouling device.

[038] The choice of material for the inner and outer tubes 30, as well as the 40 diameter transition elements, their magnetic permeability must be taken into account. Preferably, materials with a magnetic permeability of less than or slightly greater than 1 should be chosen, and more preferably with a magnetic permeability μ between 0.99 and 1.01. For example, nickel alloys can be used. 239125 2086706 of 17 (Inconel 718, 625), aluminum alloys, austenitic steels, duplex or super duplex steels, copper alloys, some stainless steels, and various polymers. The temperature and application environment, as well as the required mechanical and corrosion resistance properties, must also be taken into account. In a preferred embodiment of the invention for application in subsea oil wells, the material used may be Inconel 718.

[039] The anti-fouling device may also be provided with at least one cable protection mechanism 32 illustrated in Figure 8, preferably in the form of a channel extending along at least part of the length of the device, for protection against shocks or collisions of the cables that are required in the pipe, such as the cables of the temperature and pressure sensors, or for the actuation of valves, among others. These cable protection mechanisms 32 may be in one piece or segmented and may be arranged in the outer tube and / or in the transition elements of the diameter 40.

[040] The magnetic arrangement 10 is formed by multiple sections of magnetic arrangements distributed longitudinally around the inner tube with fluid flow inside 20. Each section 11 comprises a plurality of permanent magnets 12 fixed in a radially distributed manner on a support 13. As illustrated in Figures 2 and 3, the axisymmetric magnetic arrangement 10 comprises at least one perpendicular magnetic arrangement section 50 having magnets whose magnetic poles are oriented perpendicularly to the wall of the non-ferromagnetic inner tube 20, and at least one parallel magnetic arrangement section 51 having magnets whose magnetic poles are oriented parallel to the wall of the tube with fluid flow inside. The sections of the 239125 2086706 of 17 The magnetic arrangements shown in these figures comprise fourteen magnets, but different numbers of magnets can be used, preferably even numbers, as explained later. The dimensions of the magnets can also vary depending on the project.

[041] The sections of the magnetic arrangement may be configured in different ways. In one form, the section may be in the form of a perpendicular magnetic arrangement 50 comprising a first segment containing half of the magnets, where all of the poles are oriented in the centripetal direction, and a second segment containing the other half of the magnets, where all of the poles are oriented in the centrifugal direction. The section may also be in the form of a parallel magnetic arrangement 12 comprising a first segment containing half of the magnets, where all of the poles are oriented in a first direction parallel to the pipe, and a second segment containing the other half of the magnets, where all of the poles are oriented in a second direction opposite to the first, parallel to the pipe.

[042] As illustrated in the arrow diagram of Figure 3, the magnetic flux enters through the second segment of the perpendicular magnetic arrangement section 50 and exits towards the two parallel magnetic arrangement sections 52, through which it enters the segment with magnets whose poles are oriented in the opposite direction to the perpendicular magnetic arrangement section 50. The magnetic flux then returns from each of the parallel magnetic arrangement sections 51 to the perpendicular magnetic arrangement section 50 through the segments having magnets whose poles are oriented towards the perpendicular magnetic arrangement section 50, entering the latter through the segment in which all the poles are oriented in the centripetal direction, ensuring 239125 2086706 of 17 do the concentration of magnetic flux density within that section of perpendicular magnetic arrangement 50.

[043] In the embodiment represented by Figure 4, three sections 11 of magnet arrangement can be seen, a perpendicular magnetic arrangement section 50 with a parallel magnetic arrangement section 51 on each side. However, it should be noted that for each device, depending on its application and peculiarities, a different magnetic arrangement 10 can be used, as regards the quantity and dimensions of the sections 50 and 51 and the quantity and dimensions of the magnets.

[044] Figure 5 illustrates a longitudinal section of the device according to an embodiment of the invention, in which the arrows indicate the direction of the poles of the magnets 12. Considering this direction, the magnetic arrangement can be divided into three sectors: three diametrical sectors in the form of perpendicular magnetic arrangement sections 50 and two lateral sectors in the form of parallel magnetic arrangement sections 51. As can be seen, the direction of the poles of the magnets 12 of the lateral sectors of the parallel magnetic arrangements 51 are opposite and are perpendicular to the direction of the poles of the magnets 12 of the diametrical sector in the form of perpendicular magnetic arrangement 50.In this way, the magnetic flux density is amplified in the central region of the device and at the ends by the effect of the lateral sectors 51 that compress the magnetic flux in the diametrical sectors 50, forcing an intense magnetic flux to pass through the tube in the diametrical direction in these regions (from this fact derives its name - Diametrical Sector). A region is then created in which there is orthogonality between the Magnetic Flux Density and the Velocity of the fluid and its particles, generating the anti-fouling effect on these particles. This effect is. 239125 2086706 of 17 occurs predominantly in the diametrical area, but can also occur along the device axis depending on the details of its sizing. The different magnetic fluxes generated inside the pipe segment flowing with the fluid bring the fluid particles flowing in phase and antiphase in the direction of flow, which already reduces the adhesion of the particles to the pipe wall. Furthermore, this magnetic effect also contributes to the formation of crystals with lower adhesion (e.g., aragonite and vaterite) than crystals such as calcite (in the case of calcium carbonate), which further improves the scale prevention results of the magnetic device according to the invention.

[045] As shown in Figure 6, the direction of the poles of the magnets 12 of the parallel magnetic arrangements 51 is opposite and perpendicular to the direction of the poles of the magnets 12 of the perpendicular magnetic arrangement 50. In this way, the magnetic flux density is concentrated in the diametrical sector corresponding to the perpendicular magnetic arrangement 50 of the device.

[046] The choice of the direction of the poles of each magnet 12 in each section 11 is made to obtain the magnetic flux concentration effect already described, where the magnets 12 of the lateral sectors containing parallel magnetic arrangements 51 compress the magnetic flux in the diametrical sector containing the perpendicular magnetic arrangement 50. This effect is achieved by arranging the magnets 12 in a specific pattern similar to the Halbach arrangement, but in a novel axisymmetric configuration. For a better visualization of this arrangement with the polarities of the magnets, Figure 7 shows the perpendicular magnetic arrangement 50 of the diametrical sector and the parallel magnetic arrangements of the two lateral sections 11 adjacent to the diametrical sector 50 (one on each side). 239125 2086706 of 17 of the diametral sector) in an exploded view, and without the supports.

[047] The choice of material for the permanent magnets 12 is also a determining factor for the effectiveness of the device. To obtain a high value of magnetic flux density inside the inner tube 20, the magnet 12 with the highest energy, appropriate for the operating temperature of the device, must be chosen. In a preferred embodiment of the invention, NdFeB permanent magnets suitable for use at temperatures up to 120°C are used.

[048] It is important to note again that different arrangements of the magnetic elements may be used in the device. In addition to variations in the number and dimensions of the magnets 12 in each section 11, it is also possible to vary the dimensions and number of magnetic arrangements per diametrical 50 and lateral sectors 51, 52. Furthermore, the concentration of magnetic flux may also take place at different positions along the device and even have more than one section of perpendicular magnetic arrangement of the diametrical sector 50 in the same device.As shown in Figure 5, a topology with three diametrical sections with perpendicular magnetic arrangements 50 can be used, or even as shown in Figure 6, a topology with four diametrical sections with perpendicular magnetic arrangements 50, being able to continue with variants increasing the number of diametrical sections with perpendicular magnetic arrangements 50, following the topology presented.

[049] And even within the variants that the topology of the device can assume, 10 diametrical sectors with sections of perpendicular magnetic reinforcement arrangements 52 can be used at the ends of the magnetic arrangement, as shown in Figure 6, which under certain sizing conditions of the 239125 2086706 of 17 device seek to reinforce the magnetic flux at the ends of the device.

[050] It is also worth mentioning that, based on the solution proposed here, various antifouling magnetic devices similar to the one described here can be designed, differing only in terms of shape, dimensions (diameter, length, wall thickness of the elements), the number of polar arrangements and their positioning, and the materials. These other aspects are of secondary importance and must therefore remain within the scope protected by this invention patent.

Claims

1. Anti-fouling magnetic device, comprising: an axisymmetric anti-fouling magnetic arrangement (10) confined between a non-ferromagnetic inner tube (20) with fluid flow inside, an outer tube (30) arranged concentrically with the inner tube, and two diameter transition elements (40), each at one end of the outer and inner tubes; wherein the magnetic arrangement (10) is formed by at least one arrangement section comprising a plurality of permanent magnets (12) arranged circumferentially on a non-ferromagnetic cylindrical support;and wherein the magnetic arrangement (10) has at least one plane of concentration (50) of the magnetic flux density in a direction perpendicular to the fluid flow, the magnetic antifouling device is characterized in that the axisymmetric arrangement (10) comprises at least one perpendicular magnetic arrangement section (51) having magnets whose magnetic poles are oriented perpendicularly to the wall of the non-ferromagnetic inner tube (20), and at least one parallel magnetic arrangement section (52) having magnets whose magnetic poles are oriented parallel to the wall of the pipe with fluid flow inside. Fourteen claims follow;