Patent ID: 12243666

DETAILED DESCRIPTION

One or more specific embodiments of the present disclosure will be described below. These described embodiments are examples of the presently disclosed techniques. Additionally, in an effort to provide a concise description of these embodiments, some features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would still be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

FIG.2Ais a schematic drawing of an installation10including a cable for downhole use according to an embodiment of the disclosure. This installation10is intended to perform operations in a fluid production or injection well12made in the subsoil14.

These operations are applied by means of a downhole assembly30for carrying out actions and/or perform measurements at the bottom of the well12, such as perforations, cuttings by means of a torch, zonal isolation operations, jarring operations or further operations for setting tools into place such as setting into place a seal gasket or anchoring of a tool. Such operations may also include formation evaluation including assessing properties of the formation via sensors of the downhole assembly. These operations are carried out in any point of the well12, from the surface16.

The fluid produced in the well12is for example a hydrocarbon such as petroleum or natural gas and/or another effluent, such as steam or water, the well is an “injector” well into which liquid or gas is injected. The production tubing may contain one or several different types of fluid.

The well12is made in a cavity18positioned between the surface16of the ground and the fluid layer to be exploited (not shown) located in depth in a formation of the subsoil14.

The well12generally includes an outer tubular duct20, designated by the term of “casing”, and formed for example by an assembly of tubes applied against the formations of the subsoil14. The well12may also include at least one inner tubular duct22with a smaller diameter mounted in the outer tubular duct20. In certain cases, the well12is without any duct20,22.

The inner tubular duct22is generally designated as “production tubing”. It is formed with a metal assembly of metal tubes. It is wedged inside the outer tubular duct20for example by linings24.

The well12includes a well head stuff at the surface which selectively closes the outer tubular duct20and said or each inner tubular duct22. The well head26includes a plurality of selective access valves inside the outer tubular duct20and inside the inner tubular duct22.

The installation10includes an intervention and measurement downhole assembly30intended to be lowered into the well12through the inner tubular duct22, and a conveying cable32for deploying the downhole assembly30in the well12.

The intervention installation10further includes a sealing and alignment assembly34of the cable32, mounted on the well head26, an assembly36for deploying the cable32, positioned in the vicinity of the well head26, and a surface control unit38.

The sealing and alignment assembly34may comprise an airlock42mounted on the well head26, allowing introduction of the downhole assembly30into the well12. It also comprises a stuffing box44for achieving the seal around the cable32and return pulleys46respectively attached on the stuffing box44and on the well head26in order to send back the cable32towards the deployment assembly36.

The stuffing box44is capable of achieving a seal around the smooth outer surface of the cable32, for example via annular linings applied around this surface or/and by injecting a fluid between the outer surface and the wall of the stuffing box44.

In a so-called “open well” or “open hole” alternative, in which there is no casing20, the assembly34is mainly an assembly for aligning the cable, and may not comprise any sealing device.

The deployment assembly36includes a winch37A provided with a drum37B. The winch37A and its drum37B are laid on the ground or are optionally loaded onboard a vehicle (not shown). A spooling sleeve may be fitted around the drum37B. The winch37A is capable of winding or unwinding a given length of cable32for controlling the displacement of the downhole assembly30in the well12when moving up or down respectively. An upper end41A of the cable may be attached onto the drum37B.

The surface control unit38comprises a processor unit48and a first telemetry unit50for communicating with devices situated at the well site, for instance the winder37B and optionally the downhole assembly30, and a second telemetry unit52for communication with computers remote from the well site.

The downhole assembly30comprises a hollow case comprising an operating assembly58comprising one or several measuring module and tools62such as jarring tools or perforating tool or sensors. In some embodiment, the downhole assembly is capable of being controlled from the surface by electrical signals transmitted through the cable32. In this case, the downhole assembly also comprises a telemetry module60for communicating with the surface control unit38via the cable32via any communication system.

The cable32extends between an upper end41A, attached on the deployment assembly36at the surface, in particular on the drum37B, and a lower end41B, intended to be introduced into the well12. The downhole assembly30is suspended from the lower end41B of the cable32.

The length of the cable32, taken between the ends41A,41B may be greater than 1,000 m and is notably greater than 1,000 m and comprised between 1,000 m and 100,000 m.

In an embodiment, the cable is a slickline cable, ie a cylindrical solid cable having a smooth outer surface. In this case, the cable32has an outer diameter of less than 8 mm, advantageously less than 6 mm. The central core is formed by a single strand of solid metal cable, designated by the term “piano wire”

In another embodiment, the cable32is a wireline cable comprising one or more conductors to transmit downhole power to the downhole assembly.

Embodiments of cables that can be used as cable32in the installation will be described below.

A cable according to a first embodiment of the disclosure is shown onFIGS.3and4. As shown on the cross section ofFIG.3, the cable100comprises a core102including a conductor104(being at least one of an electrical conductor as described in relationship with the background section or of an optical conductor) and a polymer matrix106surrounding the conductor. The core has a cylindrical shape and generally extends for thousands of meters along its longitudinal axis L. The core may be a cable line, that is available off-the-shelf, a cable line assembly or a core that has been specially designed for the cable100.

The cable100also includes two layers of reinforcing elements107, a first internal layer108contacting the core and a second external layer110contacting the internal layer108. Each reinforcing element may comprise a fiber bundle including one or more reinforcement fibers impregnated with a polymer. In other words, the reinforcement fibers of the fiber bundle may be embedded in a polymer matrix. The reinforcing fibers may be carbon, aramid, basalt or glass fibers. The polymer may contain a thermoset, such as epoxy, benzoxazine, bismaleimide or cyanate ester and/or a thermoplastic such as polyketone, including polyetherketone (PEK) or polyetheretherketone (PEEK); polyphenylene sulfide (PPS) or Polyetherimide (PEI). The composition of the reinforcing element107may be chosen so that it comprises between 50% and 80% of reinforcement fibers & 50 to 20% of polymer in volume. The reinforcing element107is generally of cylindrical shape with predetermined cross-section (rectangular, circular, etc.) and, as the core, it is several thousand meter long.

As can be seen onFIG.3, each reinforcing element107is tubed by a coating112made of thermoplastic. The coating is applied on the external surface of the reinforcing element, on its entire periphery and length. The composition of the coating may include fluorinated polymer or elastomer, such as perfluoroalkoxy (PFA), polytetrafluoroethylene (PTFE), a polyketone, including polyetherketone (PEK) or polyetheretherketone (PEEK); polyphenylene sulfide (PPS) or Polyetherimide (PEI), ethylene tetrafluoroethylene (ETFE). As can be seen onFIG.3, the coating forms a layer of material surrounding the prepared reinforcing element107, at the external surface of the reinforcing element107. This differentiates from an impregnation as mentioned above in which the whole element is filled with the impregnation material.

Such cable being a composite cable and the reinforcing element (made of fibers and polymer) having a lower density than the metallic armor wires (for instance, carbon fibers and PEEK each being about 6 times less dense than steel), it enables to significantly decrease the weight of the cable. The mechanical properties of the reinforcement fibers of the reinforcing element107, in particular its high strength, enable to optimize the mechanical properties of the cable so that it is able to perform a downhole operation.

The reinforcing elements107are arranged on the cable so that each reinforcing element is able to move relative to the core and at least another reinforcing element, in particular all of the other reinforcing elements. In particular, each reinforcing element is able to move axially relative to the core and at least another reinforcing element. In this embodiment, this is achieved as there is no bond between the adjacent reinforcing elements or between each reinforcing element and the core. The fiber bundles are not embedded in a common polymer matrix immobilizing them relative to the core and the other fiber bundles placed in the common polymer matrix. In particular, in this embodiment, each reinforcing element is an independent part relative to the other reinforcing elements and devoid of connection with the adjacent reinforcing elements or core, ie is not linked to another reinforcing element through any material or mechanical bond or connection, including gluing, welding, screwing, etc.

The reinforcing elements107of the first layer108may be each wrapped helically around the cable with a same wrapping angle and are arranged so that each reinforcing element of the layer contacts the two adjacent reinforcing elements as well as the core, as can be seen onFIG.4. The wrapping angle is the angle between the reinforcing element and the longitudinal axis. An example of wrapping angle α is shown onFIG.1for the cable of the prior art. In the embodiment ofFIG.3&4, the angle may be set between 5° and 30°, in particular below 20°.

The thermoplastic coating112applied on the reinforcing element107is a lubricant that enables to reduce wear and friction induced by the movement between the reinforcing elements, as well as the general friction of the cable in the wellbore.

Further, the reinforcing elements being able to move relative to each other leverages the good properties of reinforcement fibers of said reinforcing element (ie high strength and low density) without creating a solid cylinder and keeping the ability of each reinforcing element to not damage when bending, which is necessary for such a cable that is stored wrapped on a drum. As it can be seen onFIG.4where cable is wrapped around a cylindrical element, as each of the reinforcing elements107has one or more degrees of freedom, in particular at least an axial degree of freedom, relative to the other reinforcing elements, the arrangement of reinforcing elements107may slightly be modified in order to minimize the constraints when bending the cable. For instance, it can be seen onFIG.4in locations114&116that the reinforcing elements move apart from each other when bent. Therefore this arrangement enables a longer life for the cable and a better conservation of its mechanical properties even when not in use and wound on the drum for a significant duration.

Besides, regarding rapid gas decompression, as the reinforcing elements are not linked together (ie not embedded in a matrix), gas can come out from the cable very quickly when pulling the cable out of hole (and passing from the high pressure of the well to the atmospheric pressure), without breaking damages to the cable. In other words, the cable is not prone to jail gas internally and therefore not subject the phenomenon of rapid gas decompression when the cable is conveyed out of hole and subjected to a significant pressure decrease.

When the cable includes more than one layer, the wrapping angle of the reinforcing elements in one layer may be different from the wrapping angle of reinforcing elements in another layer. Furthermore, the wrapping direction of the reinforcing elements may be different in each layer, as can be seen inFIG.4in zone116where the internal layer108is visible due to the spreading of the fibers of the external layer110. In other words, the sign of the wrapping angle in a trigonometric space may be different for the first and second layer108,110. In a particular embodiment, the wrapping angle of the first layer (relative to the longitudinal axis of the cable) is opposite to the wrapping angle of the second layer.

The tubed reinforcing elements may be conformed to match a contacting surface (ie the external surface) of the core and a contacting surface of the adjacent reinforcing elements as shown onFIG.3, in particular for the first layer of fiber108. OnFIG.3, the reinforcing elements of the first layer takes a substantially trapezoidal shape in this configuration. Such conformation may be performed applying a compression on the cable as will be explained in more details in relationship with a manufacturing method of the fiber.

Such conformation enables to perform more easily the sealing of the cable when in the wellbore. Indeed, as explained in relationship withFIG.2, when the cable is lowered in the wellbore, the cable passes in a stuffing box44that provides a pressure barrier between the well (high pressure) and the surface (low pressure). The stuffing box is shown in more details inFIG.2B. It comprises packers (or packing)400that apply a high pressure on the whole periphery of the cable as shown by the arrows402. Therefore, the packers400compress the reinforcing elements107against the core so that the reinforcing elements press against the core and/or each other. This is shown in particular inFIG.5, showing schematically the efforts120that each tubed reinforcing element107(represented by a trapeze) applies on the adjacent elements when subject to a compression122on its entire periphery. Such compression is maintained in the wellbore due to the high pressure of the wellbore. In view of the trapezoidal shape of the reinforcing elements, the entire periphery of the reinforcing elements of the first layer is contacting with the adjacent elements (core and adjacent reinforcing elements) ensuring a barrier between the core and the well fluids, providing sealing even though the reinforcing elements are not embedded in a polymer matrix.

Further, such cable does not necessitate any grease injection to obtain leak tightness at the well head as the ability of the reinforcing elements to move relative to each other and the ability of the tubing around each reinforcing element to deform enables the cable to adapt to the shape of the packers (or packing) upon compression.

In an alternative embodiment, the coatings112of at least two adjacent reinforcing elements107may be bonded to each other, for instance by plastic welding. In particular, the thermoplastic coating of a first tubed reinforcing element is bonded with the thermoplastic coating of a second tubed reinforcing element, generally adjacent to the first tubed reinforcing element, at least locally. In this case the reinforcing elements are still considered as able to move relative to each other as the reinforcing element107may be configured to move relative to the coating112, in particular slide in the tubing. The coating may in particular comprise a fluorinated polymer or elastomer that does not adhere strongly to the reinforcing element.

Such relative movement of the reinforcing elements is enabled by the structure of the cable that forms a non-uniform matrix, ie having non-uniform properties, in particular shear modulus, with a higher shear modulus for the reinforcing elements107and the core and a lower shear modulus for the bonded coatings112. Therefore, the bonded coatings are capable of damping the axial constraints, enabling relative axial movement between the reinforcing elements107without breaking. The materials of the reinforcing elements107and of the coating112may be chosen so that ratio of the shear modulus of the coating to the shear modulus of the reinforcing elements is between 0.05 and 0.5, in particular between 0.1. and 0.2. Such structure enables as well to leverage the good properties of said reinforcing element (ie high strength and low density) while enabling relative axial movement of the reinforcing elements, without breaking the cable. The relative movement between the reinforcing fibers, in particular in the axial direction are 10 to 100 times higher than when fiber bundles are embedded in an uniform matrix, in particular a uniform matrix of thermoset material. Therefore, when it is defined that the reinforcing elements are able to move relative to each other it is to be understood that the relative movement of the reinforcing elements containing the bundle of fibers without breaking is at least twice higher than if the bundle of fibers were embedded in an uniform matrix forming a rigid cylinder. In other words, this structure is a compromise between rigidity and strength that is necessary for the cable to withstand the harsh downhole conditions, and flexibility, enabling to wind and unwind the cable on a drum without damaging it.

Such embodiment where coatings112tubing reinforcing elements107are bonded to each other is shown onFIG.15. The cable ofFIG.15comprises as inFIG.3, a core102and a first and second layers108,110of tubed reinforcing elements arranged around the core. As disclosed in relationship with the above embodiments, the reinforcing elements107tubed with the coating112are conformed to contact the matching surface of the adjacent. However, as can be seen onFIG.15, the spaces130between the tubing of first and second adjacent coatings112is filled with material132in order to bond coatings112of adjacent reinforcing elements107. In this embodiment, the material132fills all spaces but the spaces may be partially filled and the coatings112of adjacent fiber being locally bonded. The material132filling the spaces may be the material of the coating112, in particular if the cable is heated so as to generate melting of the coatings112of the adjacent tubings (ie first and second coatings tubing a first and second reinforcing fiber) bonding both coatings together. In an embodiment, the material filling the spaces may be a different material than the material of the coating.

The cable ofFIG.15also includes an outer jacket140that can be made of polymer, such as a thermoplastic material. The material of the outer jacket140may be chosen so that it has a higher melting point than the thermoplastic coating112of the reinforcement elements107. Such polymer may be of the same type as the polymer of the coating but with higher melting point, for instance at least 10° C. higher. For instance, the coating of the reinforcing element may be made of ETFE LMT (ie Low Melting Temperature) whereas the outer jacket is made of ETFE EMT (High Melting Temperature). As will be explained later in relationship with the manufacturing process, such embodiment enables to form bonding or cohesion, locally or globally on the whole circumference and along the whole length of the reinforcement element, between the coating112of the reinforcement elements and the outer jacket140and between the coatings112of adjacent reinforcement elements, while preventing loss of material. Such embodiment may enable to block gas more efficiently.

The disclosure also includes additional embodiments as shown onFIG.6-10. Only the differences of these embodiments with the first embodiment are highlighted.

As shown on the embodiment ofFIG.6, the cable150includes a core152that comprises seven conductors154. In this embodiment, the cable is a wireline heptacable and the core is a standard core for such cable. Further, onFIG.6, the reinforcing elements156are flat, having a rectangular cross section with a length at least five times longer than the width, also wrapped helically around the core and tubed with a thermoplastic coating158. Reinforcing elements156with such cross section allows smaller cable radius. However, it is to be noted that other cross section of the reinforcing element (triangular, polygonal, trilobal, etc.) are also part of the current disclosure.

In the embodiment ofFIG.6, the cable comprises only one layer of reinforcing elements wrapped around the core. It is to be noted that the cable may comprise any number of reinforcing element layers and not only one or two.

In another embodiment, the reinforcing elements of at least one layer may be arranged as a fabric containing entangled tubed reinforcing elements with different orientations. In such fabric, the reinforcing elements with different wrapping orientations cross at several locations but are still able to move relative to each other, in particular axially. In an example of such fabric, the reinforcing elements170are braided, having reinforcing elements in two different wrapping orientations172,174as shown onFIG.7. On the example ofFIG.7the proportion of reinforcing elements in each orientation172,174is about 50%. However, any other way of entangling the reinforcing elements is considered as part of the disclosure. For instance, the fabric may comprise reinforcing elements in more than two orientations or have reinforcing elements of each orientation in different proportions. Further, when the cable comprises several layers, only one of the layers, for instance the external layer, may be made of such fabric of entangled reinforcing elements.

In another embodiment shown onFIG.8, a cable200includes an outer jacket202. The outer jacket may be a thermoplastic jacket, for instance made of fluorinated polymer or elastomer, such as perfluoroalkoxy (PFA), polytetrafluoroethylene (PTFE), and/or a polyketone, including polyetherketone (PEK) or polyetheretherketone (PEEK); and/or polyphenylene sulfide (PPS) and/or Polyetherimide (PEI). The outer jacket202may be a thin metallic tube, for instance crimped over the cable or a metallic braid. The jacket enables to add protection from well fluid to the cable and is able to further decrease the friction and to hold the reinforcing elements together in particular in case of damages to the cable. In an embodiment, the jacket202may be porous, in order to avoid jailing the gas in the cable, as explained in relationship with the rapid gas decompression phenomenon. In the embodiment ofFIG.8, the cable comprises four layers204-210of flat reinforcing elements represented schematically but the outer jacket may be disposed on a cable having any configuration of reinforcing elements and any number of layers.

In an additional embodiment shown onFIG.9, the cable220may comprise at least one or more metallic wires222, for instance made of copper or aluminium or copper and/or alloys comprising copper and/or aluminium, and one or more optical fibers224wrapped around the core226so as each metallic wire222or optical fiber224is able to move relative to the core and as well relative to the reinforcing elements. The optical fibers and/or metallic wires224,222may be wrapped around the core in a same layer as reinforcing elements228, as it is shown here for the metallic wires222. Alternatively, they may be set in a different layer, and also helically wrapped around the core, as shown onFIG.6for the optical fibers224. In another configuration, the optical fibers and/or metallic wires224,222may extend parallel to the longitudinal axis of the core. The metallic wires and/or optical fibers wrapped around the core may form one or more electrical and/or optical conductors of the cable.

Having the metallic wires or optical fibers in a different layer than the reinforcing elements enables to set the wrapping angle for each type of element independently, which may be useful if the mechanical properties of the elements are not the same for instance or if specific requirements apply to one of the element.

Further, the optical fibers and/or metallic wires are preferably tubed with a thermoplastic coating230like the reinforcing elements, in order to limit the friction between the different elements wrapped around the core.

In the embodiment ofFIG.9, the core does not comprise any conductor. The conductors may indeed be wrapped around the core as explained above, and, in this case, the core may have only a mechanical function. The conductors may be provided by the one or more metallic wires when these metallic wires are connected at the surface. In such case, the metallic wires may transmit power and/or communication signals from the surface to the downhole assembly or from the downhole assembly to the surface. However, the metallic wires could not be used as conductors but only as another type of reinforcements. Further, the core could comprise conductors and the metallic wires could be used as additional conductors.

In the embodiment ofFIG.9, the core may be made of material with a high Young's modulus (such as polymer associated with high Young's modulus carbon fibers or including in particular the metallic wires). Thus the cable includes material with high Young's modulus at the center and a lower Young's modulus (such as polymer associated with low Young's modulus carbon fibers) closer to the external surface so that the central portion of the cable is more flexible. Indeed, such configuration enables that the elements situated at the outer diameter of the cable (reinforcing elements or metallic wires) will be able to stretch more than the core (designed to have a high Young Modulus) during bending (ie when the cable is stored on a drum) as the outer elements are subject to more constraints when bending the cable. The core having a higher Young modulus, it has higher stiffness. Therefore for the same overall cable stiffness, such configuration increases the cable resistance to bending and cable life.

Being able to place conductors elsewhere than in the core enables a greater design flexibility for the core and to obtain such configuration. For instance, the core may comprise as well one or more of a reinforcing element (including at least a bundle of reinforcement fibers and optionally a polymer matrix) also tubed with a thermoplastic coating. The reinforcing elements may be designed (ie number and type of fibers, type and portion of polymer matrix (if any)) in order to optimize the properties of the core, in particular its Young's modulus.

The optical fibers224may enable to measure one or more characteristic of the cable in order to predict when maintenance of the cable is needed or one or more characteristic of the wellsite and/or the formation. In order to perform such measurement the fibers may be connected to an interrogator and a detector in order to be part of a Distributed Acoustic System (DAS) as described in for instance in the U.S. Pat. No. 8,225,867.

In the embodiment ofFIG.9, the cable also comprises an external liner232as disclosed in relationship withFIG.8and nude metallic wires234disposed around the liner. Such metallic wires234provide efficient electrical grounding of the cable and may either extend in a direction parallel to a longitudinal axis of the cable or to be wrapped around the outer jacket of the cable.

In another embodiment shown onFIG.10, a cable240includes a core242and tubed reinforcing elements244all extending along the longitudinal direction of the core. A jacket246covers the reinforcing elements and holds them together. In this case, the reinforcing elements may be disposed so that the core is not situated at the center of the cable but closer to a side of the cable to facilitate access to the core and maintenance and repair of the conductor(s)248situated in the core.

In another embodiment, metallic wires and/or optical fiber may be integrated in a reinforcing element. Such reinforcing element may be disposed around the core or may be part of the core. An example of reinforcing element250is shown onFIG.11. The reinforcing element250includes metallic wires252(that can be used as conductors as explained in relationship withFIG.9) in its center. A fiber bundle254is arranged around the metallic wires and a polymer matrix may impregnate the fiber bundle and the conductor. As discussed in relationship with the other embodiments, the reinforcing element is tubed by a thermoplastic coating256. Such reinforcing element may comprise any arrangement of metallic wires and fiber bundle (for instance, the metallic wires are not disposed at the center). When the metallic wires are used as conductors, the thermoplastic coating as well as the polymer matrix being an insulating material, it can be used to insulate the conductor from the other conductors. The metallic wire(s) may be replaced by one or more optical fiber or embedded with an optical fiber in the fiber bundle. Such architecture enables to gather several functions (electrical and/or optical, as well as mechanical function) in the reinforcing element and to optimize the dimensions of the cable.

An example of cable260including such reinforcing element is shown onFIG.12. Such cable260includes a core262having a reinforcing element264including a fiber bundle of reinforcement fibers and seven conductors266made of metallic wires embedded in the bundle. The conductors are made of metallic wires. The reinforcing element is tubed with a thermoplastic coating268. The cable also comprises a first layer of reinforcing elements270,272tubed with a thermoplastic coating276disposed around the core. The reinforcing elements272include a fiber optic271embedded in the bundle of reinforcement fibers. In this embodiment, the reinforcing element264is of greater dimensions than the reinforcing elements270,272of the layer surrounding the core. More generally the reinforcing elements of the cable can have different dimensions and shape.

All of the cables as per the embodiments above have been described as wireline cable, in particular in which the armor wires are replaced by the fibers enabling to decrease the density of the cable and its weight. However, such a cable design could also be applicable for other downhole cable such as a slickline cable as well as cable that have application at the surface, at the well site or in other fields of application. In this case, the dimension of the single wire could be reduced compared to current cables, also enabling to decrease the cable weight.

The cable described in the disclosure might also be used for other purpose than downhole use.

In the following a method for manufacturing the cable will be disclosed as well as a method for operating the cable.

The method300for manufacturing the cable is described in relationship withFIGS.13&14. In the flowchart ofFIG.10, the operations that are optional are represented in block with dotted line while the operations that are mandatory are represented in block with plain line.FIG.14shows a portion of an exemplary manufacturing line350of a cable according to the disclosure.

It first comprises preparing the reinforcing elements (block302). To perform this operation, each reinforcing element is tubed individually by the thermoplastic coating, generally via an extrusion process (block306). The fiber bundle of the reinforcing elements may also be impregnated by the polymer matrix (block304) before they are coated by passing the fibers in a polymer bath. The reinforcing element, after operation304, may be called a prepreg. During or before impregnation, the fiber bundle can also be conformed so that the prepreg has a predefinite section (such as cylindrical or flat). If the reinforcing element comprises a metallic wire and/or an optical fiber, the fiber bundle is arranged around the metallic wire and/or optical fiber before impregnation. Once the thermoplastic tubing has been extruded on the reinforcing elements, such prepared reinforcing elements are stored on drum. When metallic wires or optical fibers are included in the cable, they may be prepared using the same tubing operation as described in operation306and stored on a drum once tubed.

The manufacturing method then comprises providing a layer of reinforcing elements on the core (block308). The core may have been prepared separately, for instance if it is constituted of several materials but may be a standard core. If the core comprises a reinforcing element, it is prepared following the same preparation operations as disclosed above.

The manufacturing method includes wrapping the tubed reinforcing elements around the core, for instance helically wrapping the reinforcing elements over the core (block310) using a cable assembly machine, such as a planetary assembly machine352and a die354to give the cable a regular shape. In the embodiment shown onFIG.14, each of the core and a number of reinforcing elements is unwound from a different drum356;358and pass into the planetary machine352that enables a rotation of the reinforcing elements while the core only translates. Alternatively, the fibers might be braided as explained above.

Once the reinforcing elements are wrapped around the core, the manufacturing method may also comprise conforming the reinforcing elements to match the surface of the core and adjacent reinforcing elements by applying a compression on the cable once assembled (block312), for instance using compressing rolls362and a heater360for facilitating deformation of the polymer matrix (if any).

In this case a high pressure is applied on the whole periphery of the cable so that the tubed reinforcing elements, that is soft, in particular because of the uncured polymer matrix of the prepreg, deform and conform to and press against the adjacent elements, ie core and fibers.

The manufacturing method may also comprise bonding at least locally a thermoplastic coating of a first tubed reinforcing element to a thermoplastic coating of a second tubed reinforcing element, for instance by increasing the temperature beyond the melting point of the thermoplastic coating so that coatings of two adjacent tubed reinforcing elements melt and bond in a melted state by plastic welding. This might be done by using heating rollers for instance. This may be performed once the tubed reinforcing elements have been conformed, or during conformation of the tubed reinforcing elements. In a variant, a filling material may be provided to bond the coating materials of the tubed reinforcing elements by plastic welding. In other words, the coatings of a first and second reinforcing elements may be bonded by plastic welding with or without interposition of filling material.

The manufacturing also comprises, when the reinforcing elements are impregnated, curing the polymer matrix of the reinforcing elements (block314) with a heater360after they have been assembled on the core and optionally conformed and/or bonded. Indeed, the uncured reinforcing elements being assembled on the cable have more flexibility and may be assembled, and if needed conformed more easily than if the reinforcing elements were cured individually after impregnation. Once they are cured, the reinforcing elements have better mechanical properties than uncured. The core and the reinforcing elements may be stored on a drum.

If there are different layers of fibers on the cable, the same operation is renewed with the cable having core and wrapped fibers at the center of the cable assembly machine. When there are several layers of reinforcement elements, the optional conforming and curing operation may be performed only once after all of the layers of reinforcing elements have been assembled on the core. The manufacturing method may also comprise providing an outer jacket on the cable, for instance crimping a metallic tube or extruding a thermoplastic external layer (block316). This operation is not represented on the manufacturing line ofFIG.11. In an alternative, the curing and/or conforming operations may be performed after the outer jacket has been provided on the cable, for all of the layers at once (if several layers).

In a particular embodiment where the outer jacket is of higher melting point than the coatings of the reinforcing elements, the manufacturing process of the cable may include:forming, in particular, extruding the outer jacket on the reinforcing elements. In this case, as the melting point of the outer jacket is higher than the melting point of the coating of the reinforcing elements, such extrusion also leads to a cohesion between the coating material of each reinforcement element and the outer jacket material by plastic welding, at least locally, as the coating material melts during the extrusion,a conformation of the cable for instance between rollers at a temperature between the melting point of the coating and the melting point of the outer jacket. During the conformation, as explained above, the reinforcing elements deform to match a contacting surface of an adjacent tubed reinforcing element and the coatings tubed around each reinforcing element also bond at least locally by plastic welding and adhere to each other while the outer jacket keeps its shape. In certain embodiment, instead or in addition to rollers, high tension may be used on cable. Such adherence from a reinforcing element to another enables to more efficiently block the gas as it at least decreases significantly the number of interstices between the reinforcing elements.

Once the cable is conformed and/or bonded, the matrix of the reinforcing element may be cured as explained above.

As explained in relationship with all the embodiments above, the cable according to the disclosure has mechanical properties adapted to a downhole use in particular with a high strength and good resistance to bending stress while enabling to significantly reduce the weight of the cable and therefore the power for operating the cable and the footprint of the well site installation. The cable may be used in other fields of technology.

The disclosure relates to a cable having at least a conductor, wherein the cable comprises a core and a plurality of reinforcing elements arranged around the core so as to cover the core. Each reinforcing element includes at least a bundle of reinforcement fibers comprising at least one fiber and a thermoset matrix impregnating the bundle of fibers, and is individually tubed with a thermoplastic coating.

The disclosure also relates to a cable comprising a core and a plurality of reinforcing elements arranged around the core so as to cover the core. Each reinforcing element includes at least a bundle of reinforcement fibers comprising at least one fiber and each reinforcing element is individually tubed with a thermoplastic coating. The cable is configured so that each reinforcing element is able to move relative to the core and to at least another reinforcing element.

The below features may apply to one or the other of the cables:the reinforcing elements are helically wrapped around the core. In such embodiment, the wrapping angle of the reinforcing element is less than 30°, preferable 20°, wherein the wrapping angle is the angle between a longitudinal axis of the core and the fiber,the core comprises at least a conductor,At least a conductor is wrapped around the core. In particular, the at least one of the conductors is embedded in the bundle of reinforcement fibers of at least one of the reinforcing elements,At least a conductor, in particular each of the conductors, is an electrical conductor, such as a metallic wire, or an optical conductor, such as a fiber optic,the core comprises at least a reinforcing element.the thermoplastic coating comprises at least one of the following material: a fluorinated polymer or elastomer, such as perfluoroalkoxy (PFA), polytetrafluoroethylene (PTFE), a polyketone, such as polyetherketone (PEK) or polyetheretherketone (PEEK); a polyphenylene sulfide (PPS) or a polyetherimide (PEI)each reinforcing element comprises a polymer, in particular thermoset, matrix impregnating the bundle of fibers.at least a reinforcement fiber may be a carbon fiber, a glass fiber, an aramid fiber or a basalt fiber.the cable comprises a layer including tubed reinforcing elements, each reinforcing element of the layer contacting two adjacent reinforcing elements and the core. In this embodiment, at least one tubed reinforcing element may be conformed to match a contacting surface of the core and of the adjacent reinforcing elements. For instance, at least two adjacent tubed fibers may have a trapezoidal shapethe cable 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. In this embodiment, the wrapping angle of the first plurality of reinforcing elements is different from the wrapping angle from the second plurality of reinforcing elements.the cable comprises an outer jacket covering the plurality of reinforcing elements. The outer jacket may comprise a thermoplastic layer or a metallic tube.the cable may comprise a metallic wire or an optical fiber embedded in the bundle of reinforcement fibers. Alternatively, the fiber optic or conductive wire may be tubed with a thermoplastic coating. In this embodiment, the cable may comprise 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, wherein the fiber optic or conductive wire is wrapped as part of the first or second layer.at least a reinforcing element of the plurality is a flat-shaped reinforcing element.a fabric of reinforcing elements having a plurality of orientations is arranged around the core.the cable is a wireline cable for downhole use,the cable is configured so that each tubed reinforcing element is able to move, in particular axially, relative to the core and to at least another reinforcing element,the tubed reinforcing elements are independent parts, each tubed reinforcing element being devoid of connection with other reinforcing elements,alternatively, the thermoplastic coating of a first tubed reinforcing elements is at least locally bonded, in particular by plastic welding, to the thermoplastic coating of a second tubed reinforcing element, with or without interposition of a filling material.a ratio between a shear modulus of the thermoplastic material tubing the reinforcing element to the shear modulus the thermoset material impregnating the bundle of fibers of the reinforcing element is comprised between 0.05 and 0.5, preferably between 0.1 and 0.2.the cable comprises an outer jacket surrounding the tubed reinforcing elements. In this case, the thermoplastic coating of at least a tubed reinforcing elements may be at least locally bonded to the outer jacket. The material of the outer jacket may have a higher melting point than the material of the coating of the tubed reinforcing elements.

The disclosure also relates to a wellbore installation including a winch having a drum for winding a cable, a downhole tool configured to be lowered into a wellbore, and the cable according to any embodiment mentioned above, having a first end wound around the drum and the downhole tool being attached a second end.

The disclosure also relates to a method of manufacturing a downhole cable, that includes extruding a thermoplastic coating around each plurality reinforcing element of a plurality of reinforcing elements so as to form a tube around each reinforcing element. Each reinforcing element includes at least a bundle of reinforcement fibers including one or more reinforcement fibers. The method also includes arranging the plurality of tubed reinforcing elements around a core so that they cover the core and so that each reinforcing element is able to move relative to the core and to at least another reinforcing element.

In an embodiment, the method of manufacturing comprises impregnating the bundle of reinforcement fibers with a polymer before extruding the thermoplastic coating and curing the tubed reinforcing element after arranging the fibers around the core.

In an embodiment, arranging the reinforcing elements includes helically wrapping the reinforcing elements around the core.

The disclosure also relates to a method of manufacturing the cable including:a. Forming a plurality of reinforcing element, wherein forming each reinforcing element includes impregnating a bundle of reinforcement fibers including one or more reinforcement fibers with a thermoset matrix,b. extruding a thermoplastic coating around each reinforcing element of the plurality so as to form a tube around each reinforcing element,c. arranging the plurality of tubed reinforcing elements around a core so that they cover the core,d. curing the thermoset matrix of the tubed reinforcing element once arranged around the core.

In an embodiment, the method of manufacturing comprises conforming the reinforcing elements to match the surface of the core and adjacent reinforcing elements by applying a compression on the cable before the curing.

In an embodiment, the method of manufacturing comprises bonding at least locally a thermoplastic coating of a first tubed reinforcing element to a thermoplastic coating of a second tubed reinforcing element before the curing, preferably by heating the cable, in particular during or after the conforming. Such bonding is however performed before the curing.

In an embodiment, the method includes forming an outer jacket around the tubed reinforcing elements, wherein the outer jacket is made of a material having a higher melting than the thermoplastic coating tubing the reinforcing element, and wherein the conforming and/or bonding is performed after the outer jacket is formed. In this embodiment, the outer jacket may also be bonded at least locally to one or more of the coating of the reinforcement elements.