In particular, a cable for downhole use and a method of manufacturing such a cable

Abstract

The present disclosure relates to a cable (100) comprising a core (102) and a plurality of reinforcing elements (107) arranged around the core (102) to cover the core (102), wherein each reinforcing element (107) comprises at least one bundle of reinforcing fibers comprising at least one fiber and a thermoset matrix impregnating the bundle of fibers, wherein each reinforcing element (107) is individually tubularly wrapped by a thermoplastic coating (112).

Description

[0001] This application claims priority and benefit to EP application No. 19306209.8 entitled “Cable for Downhole Use”, filed on September 26, 2019, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] This disclosure relates to a cable, particularly a cable for use in downhole applications, and a method for manufacturing such a cable. Background Technology

[0003] For operations within wellbore, slickline cables or wirelines are currently used to lower downhole tools into the wellbore. Slickline cables typically consist of a single metal wire made of steel with good mechanical properties, such as a breaking strength of 300 daN to 1,500 daN, preferably 600 to 1,000 daN; that is, in some embodiments, they are coated with an insulating coating. Figure 1 As shown, the cable 1 is a cable comprising one or more central conductors 2 (here, one conductor), on which multiple layers (e.g., two layers 3, 4) of metal armored wires 5, typically made of steel, are arranged in a spiral around the one or more central conductors, usually such that each armored wire contacts two adjacent armored wires. This cable structure with metal armored wires provides strength during logging operations.

[0004] However, the density of steel makes electrical cables, to a lesser extent, and slide wire cables relatively heavy, requiring a significant amount of energy to deploy and transport the equipment. Furthermore, typical electrical cables with metal armor on their outer diameter experience high friction with the wellbore, including casing, and a considerable amount of energy is used to overcome this friction. Additionally, reaching very deep wells can be difficult because metal-reinforced cables risk breaking under their own weight.

[0005] Therefore, reducing cable weight to enable more efficient downhole operations is a goal for oil and gas fields. However, weight reduction should not compromise the cable's mechanical properties or tool operation. Summary of the Invention

[0006] This disclosure relates to a cable including a core and a plurality of reinforcing elements arranged around the core to cover the core. Each reinforcing element includes at least one bundle of reinforcing fibers, the bundle of reinforcing fibers including at least one fiber and a thermosetting matrix impregnating the bundle of fibers, and each reinforcing element is individually wrapped in a thermoplastic coated tubular shape.

[0007] This disclosure also relates to a wellbore apparatus including a winch having a drum for winding a cable, a downhole tool configured to be lowered into a wellbore, and a cable according to any of the above embodiments, with a first end wrapped around the drum and a second end attached to the downhole tool.

[0008] This disclosure also relates to a method of manufacturing downhole cables, comprising forming a plurality of reinforcing elements, including impregnating a bundle of reinforcing fibers comprising one or more reinforcing fibers with a thermosetting matrix, extruding a thermoplastic coating around each of the plurality of reinforcing elements to form a tube around each reinforcing element. The method further includes arranging a plurality of tubularly wrapped reinforcing elements around a core such that they cover the core, and curing the thermosetting matrix of the tubularly wrapped reinforcing elements once the tubularly wrapped reinforcing elements are arranged around the core.

[0009] Due to the properties of the reinforcing fibers, the cable according to this disclosure has sufficient mechanical properties, while reducing the cable density and weight, enabling power reduction when operating downhole tools, and also providing new and more economical design options for well site installations. Attached Figure Description

[0010] A better understanding of the various aspects of this disclosure can be achieved by reading the following detailed description and referring to the accompanying drawings, in which:

[0011] Figure 1 An exploded perspective view of wires and cables according to existing technology.

[0012] Figure 2A This is a schematic diagram of a well site apparatus according to an embodiment of the present disclosure.

[0013] Figure 2B yes Figure 2A Partial detailed view of the well site equipment.

[0014] Figure 3 This is a cross-section of a cable according to an embodiment of the present disclosure.

[0015] Figure 4 for Figure 3 A perspective view of the cable wound on the roller.

[0016] Figure 5 for Figure 3 A detailed diagram of the cable.

[0017] Figure 6 This is a cross-section of a cable according to another embodiment of the present disclosure.

[0018] Figure 7 This is a perspective view of a portion of a cable according to another embodiment of the present disclosure.

[0019] Figure 8-10 This is a cross-section of a cable according to other embodiments of this disclosure.

[0020] Figure 11 This is a perspective view of a portion of a cable according to an embodiment of the present disclosure.

[0021] Figure 12 Includes embodiments according to this disclosure Figure 11 The cross-section of part of the cable.

[0022] Figure 13 This is a flowchart of a cable manufacturing method according to an embodiment of the present disclosure.

[0023] Figure 14 It is based on Figure 13 A schematic diagram of a cable production line using the manufacturing method described above.

[0024] Figure 15 This is a schematic diagram of a cable according to an embodiment of the present disclosure. Detailed Implementation

[0025] One or more specific embodiments of this disclosure will now be described. These described embodiments are examples of the technology currently disclosed. Furthermore, for the purpose of providing a concise description of these embodiments, some features of actual implementations may not be described in the specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, many implementation-specific decisions may be made to achieve the developer's specific goals, such as complying with system-related and business-related constraints, which may vary from implementation to implementation. Furthermore, it should be understood that such development work may be complex and time-consuming, but remains routine work for design, fabrication, and manufacture for those skilled in the art who benefit from this disclosure.

[0026] When describing elements of various embodiments of this disclosure, the articles “a,” “an,” and “the” are intended to indicate the presence of one or more elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that additional elements may be present in addition to those listed. Furthermore, it should be understood that references to “an embodiment” or “an embodiment” in this disclosure are not intended to be construed as excluding the existence of additional embodiments that also incorporate the described features.

[0027] Figure 2 is a schematic diagram of an apparatus 10 including cables for downhole use according to an embodiment of the present disclosure. The apparatus 10 is intended to perform operations in a fluid production well or injection well 12 formed in the subsoil 14.

[0028] These operations are applied via downhole assembly 30 to perform actions and / or measurements at the bottom of well 12, such as perforation, cutting with a torch, layer isolation operations, shoveling operations, or further tool placement operations, such as placing gaskets or anchoring tools. Such operations may also include formation assessment, including evaluating formation characteristics via sensors from the downhole assembly. These operations are performed from surface 16 at any point in well 12.

[0029] The fluid produced in Well 12 is, for example, a hydrocarbon, such as oil or natural gas, and / or another effluent, such as steam or water. The well is an "injection" well, into which liquid or gas is injected. The production tubing may contain one or more different types of fluids.

[0030] Well 12 is formed in a cavity 18 between the ground surface 16 and the fluid layer to be extracted (not shown), which is located deep in the strata of the subsoil 14.

[0031] Well 12 typically includes an outer tubular conduit 20, referred to by the term "casing," formed, for example, by a tubular assembly applied to the formation of the subsoil 14. Well 12 may also include at least one inner tubular conduit 22 of a smaller diameter installed within the outer tubular conduit 20. In some cases, well 12 has neither an outer tubular conduit 20 nor an inner tubular conduit 22.

[0032] The inner tubular conduit 22 is commonly referred to as the "production tubing". It is formed from a metal assembly of a metal tube. It is wedged into the outer tubular conduit 20, for example, through a liner 24.

[0033] Well 12 includes a wellhead plug located at the surface that can selectively close the outer tubular conduit 20 and either or each inner tubular conduit 22. Wellhead 26 includes a plurality of selective inlet valves located inside the outer tubular conduit 20 and inside the inner tubular conduit 22.

[0034] The device 10 includes an intervention and measurement downhole component 30 for being lowered into the well 12 via an inner tubular conduit 22, and a delivery cable 32 for deploying the downhole component 30 in the well 12.

[0035] The intervention device 10 also includes a sealing and alignment assembly 34 for a cable 32 mounted on the wellhead 26, an assembly 36 for deploying the cable 32 located near the wellhead 26, and a surface control unit 38.

[0036] The sealing and alignment assembly 34 may include an airlock 42 mounted on the wellhead 26, allowing the downhole assembly 30 to be introduced into the well 12. It also includes a packing box 44 for sealing around the cable 32 and a return pulley 46, which are respectively attached to the packing box 44 and the wellhead 26 to return the cable 32 toward the deployment assembly 36.

[0037] The stuffing box 44 can achieve a seal around the smooth outer surface of the cable 32, for example by applying an annular liner around the surface or / and by injecting fluid between the outer surface and the wall of the stuffing box 44.

[0038] In the so-called "bare well" or "open hole" alternative, there is no external tubular conduit 20, the assembly 34 is mainly an assembly for aligning cables, and does not include any sealing device.

[0039] Deployment assembly 36 includes a winch 37A with a drum 37B. The winch 37A and its drum 37B are placed on the ground or optionally mounted on a vehicle (not shown). A winding sleeve can be mounted around the drum 37B. The winch 37A is capable of winding or unwinding a cable 32 of a given length for controlling the displacement of the downhole assembly 30 within the well 12 when moving upwards or downwards, respectively. The upper end 41A of the cable can be attached to the drum 37B.

[0040] The ground control unit 38 includes a processor unit 48 and a first telemetry unit 50 for communicating with devices located at the well site, such as roller 37B and optional downhole assembly 30, and a second telemetry unit 52 for communicating with a computer located away from the well site.

[0041] The downhole assembly 30 includes a hollow housing containing an operating assembly 58, which includes one or more measurement modules and tools, such as a slapping tool, a perforation tool, or a sensor. In some embodiments, the downhole assembly can be controlled from the surface by electrical signals transmitted via cable 32. In this case, the downhole assembly also includes a telemetry module 60 for communicating with the surface control unit 38 via cable 32 through any communication system.

[0042] Cable 32 extends between an upper end 41A and a lower end 41B, with the upper end 41A attached to a deployment assembly 36 at the ground, specifically to a roller 37B, and the lower end 41B used for entry into well 12. Downhole assembly 30 is suspended from the lower end 41B of cable 32.

[0043] The length of the cable 32 between the upper end 41A and the lower end 41B can be greater than 1,000 meters, especially greater than 1,000 meters, and between 1,000 meters and 100,000 meters.

[0044] In one embodiment, the cable is a slide wire cable, i.e., a cylindrical solid cable with a smooth outer surface 40. In this case, the outer diameter of the cable 32 is less than 8 mm, advantageously less than 6 mm. The central core is formed of a single strand of solid metal wire, referred to by the term "piano wire".

[0045] In another embodiment, cable 32 is an electrical wire or cable, including one or more conductors, for transmitting downhole power to downhole components.

[0046] An embodiment of the cable that can be used as cable 32 in the device will be described below.

[0047] The cable according to the first embodiment of this disclosure is as follows: Figure 3 and Figure 4 As shown. Figure 3As shown in the cross-section, cable 100 includes a core 102 comprising a conductor 104 (at least one of an electrical conductor or an optical conductor as described in the Background section) and a polymer matrix 106 surrounding the conductor. The core has a cylindrical shape and typically extends for several kilometers along its longitudinal axis L. The core can be an off-the-shelf cable, a cable assembly, or a core specifically designed for cable 100.

[0048] The cable 100 also includes two reinforcing elements 107, a first inner layer 108 for contact core, and a second outer layer 110 for contacting the first inner layer 108. Each reinforcing element may include a fiber bundle comprising one or more reinforcing fibers impregnated with a polymer. In other words, the reinforcing fibers of the fiber bundle may be embedded in a polymer matrix. The reinforcing fibers may be carbon, aromatic polyamide, basalt, or glass fiber. The polymer may contain thermosetting materials such as epoxy resin, benzoxazine, bismaleimide, or cyanate, and / or thermoplastic materials such as polyketone, including polyetherketone (PEK) or polyetheretherketone (PEEK); polyphenylene sulfide (PPS) or polyetherimide (PEI). The composition of the reinforcing element 107 may be selected such that it comprises between 50% and 80% reinforcing fibers and 50% to 20% by volume polymer. The reinforcing element 107 is typically cylindrical with a predetermined cross-section (rectangular, circular, etc.) and serves as a core, and is several kilometers long.

[0049] from Figure 3 As can be seen, each reinforcing element 107 is tubularly encased by a coating 112 made of thermoplastic. The coating is applied to the outer surface of the reinforcing element, covering its entire perimeter and length. The coating composition may include fluorinated polymers or elastomers, such as perfluoroalkoxy (PFA), polytetrafluoroethylene (PTFE), polyketones including polyetherketone (PEK) or polyetheretherketone (PEEK); polyphenylene sulfide (PPS) or polyetherimide (PEI), and ethylene tetrafluoroethylene (ETFE). Figure 3 As can be seen, on the outer surface of the reinforcing element 107, a coating forms a material layer surrounding the prepared reinforcing element 107. This differs from the impregnation described above, in which the entire element is filled with impregnating material.

[0050] These cables are composite cables, and the reinforcing elements (made of fibers and polymers) have a lower density than metal armored cables (e.g., carbon fiber and PEEK each have a density approximately 6 times lower than steel), thus significantly reducing cable weight. The mechanical properties of the reinforcing fibers in the reinforcing element 107, particularly their high strength, enable the optimization of the cable's mechanical properties, allowing it to perform downhole operations.

[0051] Reinforcing elements 107 are arranged on the cable such that each reinforcing element is movable relative to the core and at least one other reinforcing element, and in particular all other reinforcing elements. Specifically, each reinforcing element is axially movable relative to the core and at least one other reinforcing element. In this embodiment, this is achieved because there is no bonding between adjacent reinforcing elements or between each reinforcing element and the core. The fiber bundles are not embedded in a common polymer matrix, and are secured relative to the core and other fiber bundles placed in the common polymer matrix. Specifically, in this embodiment, each reinforcing element is an independent part relative to other reinforcing elements and is not connected to adjacent reinforcing elements or the core, i.e., not linked to another reinforcing element by any material or mechanical bonding or connection (including adhesives, welds, threaded connections, etc.).

[0052] The reinforcing elements 107 of the first inner layer 108 can each be spirally wrapped around the cable at the same wrap angle, and arranged such that each reinforcing element of this layer contacts two adjacent reinforcing elements and the core, as shown below. Figure 4 As you can see, the wrap angle is the angle between the reinforcing element and the longitudinal axis. Figure 1 An example of the wrapping angle α of a conventional cable is shown. Figure 3 and Figure 4 In some embodiments, the angle can be set between 5° and 30°, particularly less than 20°.

[0053] The thermoplastic coating 112 applied to the reinforcing element 107 is a lubricant that reduces wear and friction caused by movement between reinforcing elements, as well as general friction of cables in the wellbore.

[0054] Furthermore, the reinforcing elements, capable of moving relative to each other, utilize the desirable properties of the reinforcing fibers (i.e., high strength and low density) without forming solid cylinders and maintaining the ability of each reinforcing element not to be damaged when bent, which is essential for such cables stored wrapped in rollers. Figure 4 As can be seen, the cable is wound around a cylindrical element. Since each reinforcing element 107 has one or more degrees of freedom relative to other reinforcing elements, particularly at least one axial degree of freedom, the arrangement of the reinforcing elements 107 can be slightly modified to minimize constraints when bending the cable. For example, from Figure 4 As can be seen at positions 114 and 116, the reinforcing elements move apart from each other when bent. Therefore, this arrangement results in a longer cable lifespan and better maintenance of its mechanical properties, even when not in use for extended periods and wrapped around a roller.

[0055] Furthermore, regarding rapid gas decompression, because the reinforcing elements are not linked together (i.e., not embedded in the matrix), gas can escape very quickly from the cable when it is pulled out of the borehole (from the high pressure of the well to atmospheric pressure) without damaging the cable. In other words, the cable does not easily retain gas inside, so rapid gas decompression does not occur when the cable is transported out of the borehole and subjected to a significant pressure drop.

[0056] When a cable consists of more than one layer, the wrapping angle of the reinforcing element in one layer may differ from that in another layer. Furthermore, the wrapping direction of the reinforcing element can be different in each layer, such as... Figure 4 As can be seen in region 116, the first inner layer 108 is visible due to the fiber unfolding of the second outer layer 110. In other words, the wrap angle signs in the triangular space can be different for the first inner layer 108 and the second outer layer 110. In a particular embodiment, the wrap angle of the first layer (relative to the longitudinal axis of the cable) is opposite to that of the second layer.

[0057] The tubular reinforcing element can be conformally fitted to match the contact surface of the core (i.e., the outer surface) and the contact surface of adjacent reinforcing elements, such as... Figure 3 As shown, specifically for the first inner layer 108. In Figure 3 In this configuration, the first layer of reinforcing elements is essentially trapezoidal. This conformation can be achieved by applying pressure to the cable, which will be explained in more detail in relation to optical fiber manufacturing methods.

[0058] This conformal design makes sealing the cable easier as it descends into the wellbore. In fact, as explained in conjunction with Figure 2, as the cable descends into the wellbore, it passes through the packing box 44, which provides a pressure barrier between the well (high pressure) and the surface (low pressure). Figure 2B More details of the filler box are shown. It includes a packer (or filler) 400, as indicated by arrow 402, which applies high voltage across the entire periphery of the cable. Therefore, the packer 400 presses the reinforcing element 107 against the core, such that the reinforcing elements press against the core and / or against each other. This is particularly evident in… Figure 5 The diagram schematically illustrates the force 120 exerted by each tubularly wrapped reinforcing element 107 (represented by a trapezoid) on its adjacent element when compressed 122 across its entire periphery. This compression is maintained within the wellbore due to the high pressure. Given the trapezoidal shape of the reinforcing elements, the entire periphery of the first layer of reinforcing elements is in contact with the adjacent elements (core and adjacent reinforcing elements), ensuring a barrier between the core and the well production fluid, providing a seal even if the reinforcing elements are not embedded in the polymer matrix.

[0059] Furthermore, this type of cable does not require the injection of any grease to achieve wellhead sealing, because the ability of the reinforcing elements to move relative to each other and the ability of the tubing around each reinforcing element to deform allows the cable to adapt to the shape of the packer (or packing) when compressed.

[0060] In an alternative embodiment, the coatings 112 of at least two adjacent reinforcing elements 107 may be bonded to each other, for example, by means of plastic welding. Specifically, the thermoplastic coating of the first tubularly wrapped reinforcing element is at least partially bonded to the thermoplastic coating of a second tubularly wrapped reinforcing element that is typically adjacent to the first tubularly wrapped reinforcing element. In this case, the reinforcing elements are still considered movable relative to each other because the reinforcing elements 107 can be configured to move relative to the coatings 112, particularly sliding within the tube. The coatings may specifically comprise fluoropolymers or elastomers that do not adhere firmly to the reinforcing elements.

[0061] This relative movement of the reinforcing elements is achieved by a cable structure forming a non-uniform matrix (i.e., having non-uniform properties, particularly shear modulus), with the reinforcing element 107 and the core having high shear modulus and the combined coating 112 having low shear modulus. Therefore, the combined coating dampens axial constraints, allowing the reinforcing elements 107 to move relative to each other axially without breaking. The materials of the reinforcing element 107 and the coating 112 can be chosen such that the ratio of the coating's shear modulus to the reinforcing element's shear modulus is between 0.05 and 0.5, particularly between 0.1 and 0.2. This structure also allows the utilization of the good properties of the reinforcing elements (i.e., high strength and low density) while allowing the reinforcing elements to move relative to each other axially without damaging the cable. The relative movement between the reinforcing fibers, particularly in the axial direction, is 10 to 100 times greater than when the fiber bundle is embedded in a uniform matrix, particularly a thermosetting material. Therefore, when defining the ability of the reinforcing elements to move relative to each other, it should be understood that the relative movement of reinforcing elements containing fiber bundles without breaking is at least twice as high as if the fiber bundles were embedded in a uniform matrix forming a rigid cylinder. In other words, this structure is a compromise between the rigidity and strength required for the cable to withstand harsh downhole conditions and the flexibility required to wind the cable onto or unwind it from the drum without damaging it.

[0062] An embodiment in which the reinforcing element 107 is bonded to the tubular coating 112 is, for example... Figure 15 As shown. Figure 3 As shown, Figure 15 The cable includes a core 102 and a first inner layer 108 and a second outer layer 110 arranged around the core and tubularly wrapped. As disclosed with respect to the above embodiments, a reinforcing element 107 tubularly wrapped with coating 112 is conformally adapted to contact adjacent mating surfaces. However, as... Figure 15As shown, the space 130 between the tubular sections of the first and second adjacent coatings 112 is filled with material 132 to bond the coatings 112 of the adjacent reinforcing elements 107. In this embodiment, material 132 fills all the spaces, but these spaces may be partially filled, and the coatings 112 of adjacent fibers may be partially bonded. The material 132 filling the spaces may be the same material as the coatings 112, particularly if the cable is heated to melt the coatings 112 of the adjacent tubular sections (i.e., the first and second coatings of the first and second reinforcing fibers forming tubules), thereby bonding the two coatings together. In one embodiment, the material filling the spaces may be a different material than the coating material.

[0063] Figure 15 The cable also includes an outer sheath 140 made of a polymer such as a thermoplastic material. The material of the outer sheath 140 can be selected such that it has a higher melting point than the thermoplastic coating 112 of the reinforcing element 107. This polymer can be the same type as the coating polymer but has a higher melting point, for example, at least 10°C higher. For example, the coating of the reinforcing element can be made of ETFE LMT (i.e., low melting temperature), while the outer sheath is made of ETFE HMT (high melting temperature). As will be explained later in conjunction with the manufacturing process, this embodiment enables the formation of a bond or cohesion, locally or integrally, between the coating 112 of the reinforcing element and the outer sheath 140, and between the coatings 112 of adjacent reinforcing elements, along the entire circumference of the reinforcing element and along its entire length, while preventing material loss. This embodiment can more effectively block gases.

[0064] This disclosure also includes Figure 6-10 The additional embodiments shown are only highlighted in light of the differences between these embodiments and the first embodiment.

[0065] like Figure 6 As shown in the embodiment, cable 150 includes a core 152 comprising seven conductors 154. In this embodiment, the cable is a seven-core cable, and the cores are standard cores for this type of cable. Furthermore, in Figure 6 In this design, the reinforcing element 156 is flat, has a rectangular cross-section, and is at least five times its width in length. It is also spirally wound around the core and tubularly wrapped by a thermoplastic coating 158. The reinforcing element 156 with this cross-section allows for a smaller cable radius. However, it should be noted that other cross-sections of the reinforcing element (triangular, polygonal, trefoil, etc.) are also part of the present disclosure.

[0066] exist Figure 6 In this embodiment, the cable includes only one layer of reinforcing element surrounding the core. It should be noted that the cable may include any number of reinforcing element layers, not just one or two layers.

[0067] In another embodiment, at least one layer of reinforcing elements may be arranged as a fabric comprising reinforcing elements entangled and tubularly wrapped with different orientations. In such a fabric, reinforcing elements with different wrapping orientations intersect at several locations but are still able to move relative to each other, particularly axially. In one example of such a fabric, reinforcing element 170 is woven, as... Figure 7 As shown, reinforcing elements are present on two different wrapping orientations 172 and 174. Figure 7 In the example, the proportion of reinforcing elements on each orientation 172, 174 is approximately 50%. However, any other manner of tangling reinforcing elements is considered part of this disclosure. For example, the fabric may include reinforcing elements in more than two orientations, or reinforcing elements in different proportions for each orientation. Furthermore, when the cable comprises several layers, only one layer, such as the outer layer, may be made of fabric with such tangled reinforcing elements.

[0068] exist Figure 8 In another embodiment shown, the cable 200 includes an outer sheath 202. The outer sheath may be a thermoplastic sheath, for example made of a fluoropolymer or elastomer, such as perfluoroalkoxy (PFA), polytetrafluoroethylene (PTFE), and / or polyketone, including polyetherketone (PEK) or polyetheretherketone (PEEK); and / or polyphenylene sulfide (PPS) and / or polyetherimide (PEI). The outer sheath 202 may be a thin metal tube, for example, crimped onto the cable or metal braid. The sheath increases protection of the cable from well fluids and further reduces friction, as well as holding reinforcing elements together, especially in the event of cable damage. In one embodiment, the sheath 202 may be porous to prevent gas from becoming trapped in the cable, as explained by the phenomenon of rapid gas decompression. Figure 8 In one embodiment, the cable includes four layers of 204-210 flat reinforcing elements, as schematically shown, but the outer sheath can be provided on the cable with any reinforcing element configuration and any number of layers.

[0069] exist Figure 9 In the additional embodiment shown, cable 220 may include at least one or more metal wires 222, for example made of copper or aluminum or copper and / or copper and / or aluminum alloys; and one or more optical fibers 224 wrapped around core 226 so that each metal wire 222 or optical fiber 224 is movable relative to the core and relative to the reinforcing element. The optical fibers and / or metal wires 222, 224 may be wrapped around the core in the same layer as the reinforcing element 228, as shown here with respect to metal wire 222. Alternatively, they may be arranged in different layers and also spirally wrapped around the core, as shown here with respect to metal wire 222. Figure 6As shown for fiber 224. In another configuration, the fiber optic and / or metal wires 222, 224 may extend parallel to the longitudinal axis of the core. The metal wires and / or fiber optics wrapped around the core may form one or more electrical and / or optical conductors of the cable.

[0070] Placing metal wires or optical fibers on different layers from reinforcing elements allows for independent setting of the wrap angle for each type of element. This can be useful, for example, if the elements have different mechanical properties, or if specific requirements apply to one type of element.

[0071] Furthermore, the optical fiber and / or metal wire are preferably wrapped in a tubular shape by a thermoplastic coating 230, similar to a reinforcing element, to limit friction between different elements wrapped around the core.

[0072] exist Figure 9 In some embodiments, the core does not include any conductor. As mentioned above, a conductor can indeed be wrapped around the core, and in this case, the core can have only a mechanical function. When these metal wires are connected at the surface, the conductor can be provided by one or more metal wires. In this case, the metal wires can transmit electrical and / or communication signals from the surface to the downhole assembly, or from the downhole assembly to the surface. However, the metal wires cannot be used as conductors, but only as another type of reinforcing material. Furthermore, the core may include a conductor, and the metal wires can be used as additional conductors.

[0073] exist Figure 9 In some embodiments, the core may be made of a material with a high Young's modulus (e.g., a polymer associated with high Young's modulus carbon fibers, or particularly including metal wires). Therefore, the cable includes a material with a high Young's modulus at the center and a lower Young's modulus closer to the outer surface (e.g., a polymer associated with low Young's modulus carbon fibers), making the central portion of the cable more flexible. In fact, this configuration allows the elements located at the outer diameter of the cable (reinforcing elements or metal wires) to stretch more during bending (i.e., when the cable is stored on a roller) than the core (designed to have a high Young's modulus), because the outer elements are more constrained when bending the cable. The core has a higher Young's modulus, which results in higher stiffness. Therefore, for the same overall cable stiffness, this configuration increases the cable's resistance to bending and cable life.

[0074] The conductor can be placed in locations other than the core, giving the core greater design flexibility and enabling such configurations. For example, the core may also include one or more reinforcing elements (comprising at least one bundle of reinforcing fibers and an optional polymer matrix), which are also encased in a thermoplastic-coated tubular form. The reinforcing elements (i.e., the number and type of fibers, the type and portion of the polymer matrix, if any) can be designed to optimize the core's performance, particularly its Young's modulus.

[0075] Core 226 may be able to measure one or more characteristics of the cable to predict when maintenance of the cable or one or more characteristics of the well site and / or formation is required. To perform such measurements, the optical fiber may be connected to interrogators and detectors to become part of a distributed acoustic system (DAS), such as that described in U.S. Patent No. 8,225,867.

[0076] exist Figure 9 In one embodiment, the cable also includes a combination Figure 8 The disclosed features an outer liner 232 and bare metal wires 234 arranged around the liner. These bare metal wires 234 provide effective electrical grounding for the cable and can extend in a direction parallel to the longitudinal axis of the cable or wrap around the outer sheath of the cable.

[0077] exist Figure 10 In another embodiment shown, the cable 240 includes a core 242 and a tubularly wrapped reinforcing element 244 extending longitudinally along the core. A sheath 246 covers the reinforcing element and holds them together. In this case, the reinforcing element can be arranged such that the core is not located at the center of the cable, but rather closer to one side of the cable, to facilitate access to the core and maintenance and repair of the conductor 248 located within the core.

[0078] In another embodiment, metal wires and / or optical fibers may be integrated into the reinforcing element. This reinforcing element may be disposed around the core, or it may be part of the core. Figure 11 An example of a reinforcing element 250 is shown. The reinforcing element 250 includes a metal wire 252 at its center (as shown in the diagram). Figure 9 As explained, it can be used as a conductor. Fiber bundles 254 are arranged around the metal wire, and the polymer matrix can impregnate the fiber bundles and the conductor. As discussed with respect to other embodiments, the reinforcing element is tubularly wrapped by a thermoplastic coating 256. This reinforcing element can include any arrangement of the metal wire and fiber bundle (e.g., the metal wire is not centrally located). When the metal wire is used as a conductor, the thermoplastic coating, along with the polymer matrix, is an insulating material that can be used to insulate the conductor from other conductors. The metal wire can be replaced by one or more optical fibers, or embedded in a fiber bundle together with the optical fibers. This structure enables the integration of multiple functions (electrical and / or optical, as well as mechanical functions) in the reinforcing element and optimizes cable dimensions.

[0079] Figure 12An example of a cable 260 including such a reinforcing element is shown. This cable 260 includes a core 262 with a reinforcing element comprising a bundle of reinforcing fibers and seven conductors 266 made of metal wire embedded in the bundle. The conductors are made of metal wire. The reinforcing element is tubularly wrapped with a thermoplastic coating 268. The cable also includes first-layer reinforcing elements 270, 272, which are tubularly wrapped with a thermoplastic coating 276 disposed around the core. Reinforcing element 272 includes optical fibers 274 embedded in the reinforcing fiber bundle. In this embodiment, the core 262 is larger than the layers of reinforcing elements 270, 272 surrounding the core. More generally, the reinforcing elements of a cable can have different sizes and shapes.

[0080] All cables in the above embodiments are described as electrical wires, specifically where the armor wires are replaced by fibers, thereby reducing cable density and weight. However, this cable design can also be applied to other downhole cables, such as slide wire cables, as well as cables used on the surface, at well sites, or in other applications. In this case, the size of a single wire can be reduced compared to existing cables, thus reducing cable weight.

[0081] The cables described in this disclosure can also be used for other purposes in downhole applications.

[0082] The following will disclose methods for manufacturing cables and methods for handling cables.

[0083] Method 300 for manufacturing cables Figure 13 and 14 Describe it. In Figure 10 In the flowchart, optional operations are represented by dashed boxes, while mandatory operations are represented by solid boxes. Figure 14 A portion of an exemplary production line 350 for cables according to this disclosure is shown.

[0084] The process begins with the preparation of the reinforcing element (box 302). To perform this operation, each reinforcing element is typically individually tubularly wrapped by a thermoplastic coating via an extrusion process (box 306). The fiber bundles of the reinforcing element may also be impregnated with a polymer matrix before they are coated by passing the fibers through a polymer bath (box 304). After operation 304, the reinforcing element may be referred to as a prepreg. During or before impregnation, the fiber bundles may also be shaped such that the prepreg blank has a predetermined cross-section (e.g., cylindrical or flat). If the reinforcing element comprises metal wire and / or optical fiber, the fiber bundle is arranged around the metal wire and / or optical fiber before impregnation. Once the thermoplastic tubing is extruded onto the reinforcing element, the thus prepared reinforcing element is stored on a roller.

[0085] When the cable includes metal wires or optical fibers, they can be prepared using the same tubing operation described in Operation 306, and once tubed, they are stored on a roller.

[0086] The manufacturing method includes providing a reinforcing element (box 308) on the core. The core can be prepared separately, for example, if it is composed of several materials, but it can be a standard core. If the core contains a reinforcing element, it is prepared according to the same preparation operations as described above.

[0087] The manufacturing method involves wrapping a tubular reinforcing element around a core, for example using a cable assembly machine, such as planetary assembly machine 352, and mold 354 to spirally wrap the reinforcing element around the core (frame 310) to give the cable a regular shape. Figure 14 In the illustrated embodiment, each core and multiple reinforcing elements are unrolled from different rollers 356 and 358 and passed into a planetary assembly machine 352, which allows the reinforcing elements to rotate while the core only translates. Alternatively, the fibers can be woven as described above.

[0088] Once the reinforcing element is wrapped around the core, the manufacturing method may also include conforming the reinforcing element to match the surfaces of the core and adjacent reinforcing elements by applying compression to the assembled cable, for example using compression rollers 362 and heaters 360 (box 312), to promote deformation of the polymer matrix (if any).

[0089] In this case, high pressure is applied to the entire periphery of the cable, causing the flexible, tubular reinforcing element, especially due to the uncured polymer matrix of the prepreg blank, to deform and conform to and press against adjacent elements, namely the core and fibers.

[0090] The manufacturing method may further include at least partially bonding the thermoplastic coating of the first tubularly enclosed reinforcing element to the thermoplastic coating of the second tubularly enclosed reinforcing element, for example, by heating the temperature above the melting point of the thermoplastic coating to melt the coatings of the two adjacent tubularly enclosed reinforcing elements and bonding them in the molten state by plastic welding. This can be accomplished, for example, using heated rollers. This can be performed when the tubularly enclosed reinforcing element has been shaped, or during the shaping process of the tubularly enclosed reinforcing element. In a variation, a filler material may be provided to bond the coating materials of the tubularly enclosed reinforcing elements by plastic welding. In other words, the coatings of the first and second reinforcing elements can be bonded by plastic welding with or without the insertion of filler material.

[0091] The manufacturing process also includes curing the polymer matrix of the reinforcing element with a heater 360 (box 314) after the reinforcing element has been assembled onto the core and optionally shaped and / or bonded, while the reinforcing element is impregnated. In fact, uncured reinforcing elements assembled onto the cable have greater flexibility and can be assembled and, if needed, more easily shaped than reinforcing elements cured separately after impregnation. Once cured, the reinforcing elements have better mechanical properties than uncured ones. The core and reinforcing elements can be stored on rollers.

[0092] If the cable has different fiber layers, the same operation is performed on cables with cores and wrapped fibers at the center of the cable assembly machine. When there are several layers of reinforcing elements, the optional conforming and curing operation can be performed only once after all the reinforcing elements of all layers have been assembled onto the core. The manufacturing method may also include providing an outer sheath on the cable, such as a crimped metal tube or an extruded thermoplastic outer layer (box 316). This operation is not performed in... Figure 11 The production line display shows that, as an alternative, curing and / or conformal processing can be performed after the outer sheath has been provided on the cable, applying all layers (if there are several layers) at once.

[0093] In a particular embodiment, where the melting point of the outer sheath is higher than the melting point of the reinforcing element coating, the cable manufacturing process may include:

[0094] – Formation, particularly the extrusion of the outer sheath onto the reinforcing element. In this case, because the melting point of the outer sheath is higher than that of the coating of the reinforcing element, this extrusion also leads to adhesion between the coating material of each reinforcing element and the outer sheath material through plastic welding, at least locally, because the coating material melts during the extrusion process.

[0095] - Conforming cables are, for example, shaped between rollers at a temperature between the melting point of the coating and the melting point of the outer sheath. As described above, during the conforming process, reinforcing elements deform to match the contact surfaces of adjacent tubularly wrapped reinforcing elements, and the tubularly wrapped coatings around each reinforcing element are also at least partially bonded by plastic welding and adhered to each other, while the outer sheath maintains its shape. In some embodiments, high tension can be used on the cable instead of rollers or in addition to rollers. This adhesion from one reinforcing element to another can more effectively block gas because it at least significantly reduces the number of voids between the reinforcing elements.

[0096] Once the cable is conformally fitted and / or bonded, the matrix of the reinforcing element can be cured as described above.

[0097] As described in conjunction with all the above embodiments, the cable according to this disclosure has mechanical properties suitable for downhole use, particularly high strength and good resistance to bending stress, while significantly reducing cable weight, thereby reducing the power consumption of the operating cable and the footprint of the well site equipment. This cable can be used in other technical fields.

[0098] This disclosure relates to a cable having at least one conductor, wherein the cable includes a core and a plurality of reinforcing elements arranged around the core to cover the core. Each reinforcing element includes at least one bundle of reinforcing fibers, the bundle of reinforcing fibers including at least one fiber and a thermosetting matrix impregnating the bundle of fibers, and each reinforcing element is individually wrapped in a thermoplastic coated tubular shape.

[0099] This disclosure also relates to a cable comprising a core and a plurality of reinforcing elements arranged around the core to cover the core. Each reinforcing element includes at least one bundle of reinforcing fibers, the bundle of reinforcing fibers comprising at least one fiber, and each reinforcing element is individually wrapped in a thermoplastic-coated tubular form. The cable is configured such that each reinforcing element is movable relative to the core and at least one other reinforcing element.

[0100] The following features may apply to one type of cable or another type of cable:

[0101] - The reinforcing element is spirally wound around the core. In such an embodiment, the wrapping angle of the reinforcing element is less than 30°, preferably 20°, where the wrapping angle is the angle between the longitudinal axis of the core and the fiber.

[0102] - The core includes at least one conductor.

[0103] - At least one conductor is wrapped around the core. Specifically, this conductor, or at least one conductor, is embedded in a reinforcing fiber bundle containing at least one reinforcing element.

[0104] - At least one conductor, specifically each conductor, is an electrical conductor, such as a metal wire, or an optical conductor, such as an optical fiber.

[0105] - The core includes at least one reinforcing element.

[0106] - Thermoplastic coatings include at least one of the following materials: fluorinated polymers or elastomers, such as perfluoroalkoxy (PFA), polytetrafluoroethylene (PTFE), polyketones, such as polyether ketone (PEK) or polyether ether ketone (PEEK); polyphenylene sulfide (PPS) or polyetherimide (PEI).

[0107] - Each reinforcing element comprises a polymer, particularly a thermosetting polymer, and a matrix-impregnated fiber bundle.

[0108] - At least one reinforcing fiber can be carbon fiber, glass fiber, aramid fiber or basalt fiber.

[0109] The cable includes a layer comprising tubularly wrapped reinforcing elements, each reinforcing element contacting two adjacent reinforcing elements and the core. In this embodiment, at least one tubularly wrapped reinforcing element may be conformally shaped to match the contact surfaces of the core and adjacent reinforcing elements. For example, at least two adjacent tubular optical fibers may have a trapezoidal shape.

[0110] The cable includes a first layer and a second layer. The first layer includes a first plurality of reinforcing elements wrapped around a core, and the second layer includes a second plurality of reinforcing elements wrapped around the first layer. In this embodiment, the wrapping angle of the first plurality of reinforcing elements is different from the wrapping angle of the second plurality of reinforcing elements.

[0111] - The cable includes an outer sheath covering multiple reinforcing elements. The outer sheath may include a thermoplastic layer or a metal tube.

[0112] - The cable may include metal wires or optical fibers embedded in reinforcing fiber bundles. Alternatively, the optical fibers or wires may be wrapped in a thermoplastic-coated tubular form. In this embodiment, the cable may include a first layer and a second layer, the first layer including a first plurality of reinforcing elements wrapped around a core, and the second layer including a second plurality of reinforcing elements wrapped around the first layer, wherein the optical fibers or wires are wrapped as part of the first or second layer.

[0113] - At least one of the multiple reinforcing elements is a flat-shaped reinforcing element.

[0114] - A fabric with reinforcing elements in multiple directions is arranged around the core.

[0115] - Cables are electrical wires and cables used underground.

[0116] - The cable is configured such that each tubular-encased reinforcing element can move relative to the core and at least one other reinforcing element, particularly axially.

[0117] - The tubular reinforcing elements are independent components; each tubular reinforcing element is not connected to any other reinforcing element.

[0118] - Alternatively, the thermoplastic coating of the first tubularly encased reinforcing element is, with or without inserting filler material, particularly by plastic welding, at least partially bonded to the thermoplastic coating of the second tubularly encased reinforcing element.

[0119] - The ratio of the shear modulus of the thermoplastic material in which the reinforcing element is tubularly wrapped to the shear modulus of the thermosetting material in which the fiber bundle of the reinforcing element is impregnated is between 0.05 and 0.5, preferably between 0.1 and 0.2.

[0120] - The cable includes an outer sheath surrounding a reinforcing element that is tubularly encased. In this case, at least one thermoplastic coating of the tubularly encased reinforcing element may be at least partially bonded to the outer sheath. The material of the outer sheath may have a higher melting point than the coating material of the tubularly encased reinforcing element.

[0121] This disclosure also relates to a wellbore apparatus including a winch having a drum for winding a cable, a downhole tool configured to be lowered into a wellbore, and a cable according to any of the above embodiments, with a first end wrapped around the drum and a second end attached to the downhole tool.

[0122] This disclosure also relates to a method of manufacturing downhole cables, comprising extruding a thermoplastic coating around each of a plurality of reinforcing elements to form a tube around each reinforcing element. Each reinforcing element includes at least one bundle of reinforcing fibers, the bundle of reinforcing fibers comprising one or more reinforcing fibers. The method further includes arranging a plurality of tubularly wrapped reinforcing elements around a core such that they cover the core, and such that each reinforcing element is movable relative to the core and at least one other reinforcing element.

[0123] In one embodiment, the manufacturing method includes impregnating reinforcing fiber bundles with a polymer prior to extruding a thermoplastic coating, and curing the tubularly wrapped reinforcing element after the fibers are arranged around a core.

[0124] In one embodiment, arranging the reinforcing element includes spirally wrapping the reinforcing element around the core.

[0125] This disclosure also relates to a method of manufacturing a cable, comprising:

[0126] a. Forming multiple reinforcing elements, wherein forming each reinforcing element includes impregnating a bundle of reinforcing fibers comprising one or more reinforcing fibers with a thermosetting matrix.

[0127] b. Extrude a thermoplastic coating around each of the plurality of reinforcing elements to form a tube around each reinforcing element.

[0128] c. Multiple reinforcing elements, encased in tubular structures, are arranged around the core, covering it.

[0129] d. Once arranged around the core, the thermosetting matrix of the reinforcing element, which is encased in a tubular structure, is cured.

[0130] In one embodiment, the manufacturing method includes, prior to curing, conforming the reinforcing element to match the surfaces of the core and adjacent reinforcing elements by applying compression to the cable.

[0131] In one embodiment, the manufacturing method includes, prior to curing, preferably by means of a heating cable, particularly during or after conformal fitting, at least partially bonding a thermoplastic coating of a first tubularly wrapped reinforcing element to a thermoplastic coating of a second tubularly wrapped reinforcing element. However, this bonding is performed prior to curing.

[0132] In one embodiment, the method includes forming an outer sheath around a reinforcing element that is tubularly enclosed, wherein the outer sheath is made of a material with a melting point higher than that of the thermoplastic coating that causes the reinforcing element to be tubularly enclosed, and wherein conformal fitting and / or bonding are performed after the outer sheath is formed. In this embodiment, the outer sheath may also be at least partially bonded to one or more coatings of the reinforcing element.

Claims

1. A cable having at least one conductor, wherein, The cable comprises a core and a plurality of reinforcing elements arranged around the core to cover the core, wherein each reinforcing element comprises one or more metal wires and a plurality of reinforcing fibers disposed around the one or more metal wires, wherein the plurality of reinforcing fibers and the one or more metal wires are impregnated with a thermoset matrix, wherein each reinforcing element is individually tubularly wrapped by a thermoplastic coating.

2. The cable of claim 1, wherein, At least one of the conductors is an electrical conductor, or an optical conductor.

3. The cable of claim 1, wherein, Each reinforcing element is conformed to match a contact surface of the core and a contact surface of an adjacent reinforcing element.

4. The cable of claim 1, wherein, It comprises a first layer comprising a first plurality of reinforcing elements wrapped around the core and a second layer comprising a second plurality of reinforcing elements wrapped around the first layer and in contact with the first layer.

5. The cable of claim 3, configured so that each tubularly wrapped reinforcing element is movable relative to the core and at least one other reinforcing element.

6. The cable of claim 3, configured so that each tubularly wrapped reinforcing element is axially movable relative to the core and at least one other reinforcing element.

7. The cable according to any one of claims 1 to 6, wherein, The tubularly wrapped reinforcing elements are independent components, each tubularly wrapped reinforcing element being free of connection to other reinforcing elements.

8. The cable according to any one of claims 1 to 6, wherein, The thermoplastic coating of the first tubularly wrapped reinforcing element is at least partially bonded to the thermoplastic coating of the second tubularly wrapped reinforcing element.

9. The claim of claim 8, wherein, The thermoplastic coatings of the first and second tubularly wrapped reinforcing elements are bonded by plastic welding.

10. The cable of any of claims 1 to 6, wherein, The ratio of the shear modulus of the thermoplastic material in which the reinforcing elements are tubularly wrapped to the shear modulus of the thermoset material impregnating the fibers of the reinforcing elements is between 0.05 and 0.

5.

11. The cable of any of claims 1 to 6, wherein, The ratio of the shear modulus of the thermoplastic material in which the reinforcing elements are tubularly wrapped to the shear modulus of the thermoset material impregnating the fibers of the reinforcing elements is between 0.1 and 0.

2.

12. The cable of any one of claims 1 to 6, comprising an outer jacket surrounding the tubularly wrapped reinforcing elements.

13. The cable of claim 12, wherein, The thermoplastic coating of at least one of the tubularly wrapped reinforcing elements is at least partially bonded to the outer jacket.

14. The cable of claim 12, wherein, The material of the outer jacket has a higher melting point than the material of the coating of the tubularly wrapped reinforcing elements.

15. A wellbore apparatus comprising: a winch having a drum for winding a cable, a downhole tool configured to be lowered into a wellbore, a cable according to any one of claims 1 to 14, the first end being wrapped around the drum and the second end being attached to the downhole tool.

16. A method of manufacturing a cable, comprising: a. forming a plurality of reinforcing elements, wherein forming each reinforcing element comprises arranging a plurality of reinforcing fibers around one or more metal wires and impregnating the plurality of reinforcing fibers and the one or more metal wires with a thermoset matrix, b. extruding a thermoplastic coating around each of the plurality of reinforcing elements so as to form a tube around each reinforcing element, c. arranging the plurality of reinforcing elements around a core so that they cover the core, d. solidifying the thermoset matrix after the plurality of reinforcing elements have been arranged around the core.

17. The method of manufacturing a cable according to claim 16, further comprising conforming the reinforcing elements to match the surface of the core and adjacent reinforcing elements by applying compression on the cable prior to curing.

18. The method of manufacturing a cable according to claim 16, comprising at least partially bonding the thermoplastic coating of the first reinforcing element to the thermoplastic coating of the second reinforcing element by heating the cable prior to curing.

19. The method of manufacturing a cable according to any one of claims 16 to 18, comprising forming an outer jacket around the reinforcing elements, wherein the outer jacket is made of a material having a higher melting point than the thermoplastic coating, and wherein the conforming and / or bonding is performed after the outer jacket is formed.

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