Patent Publication Number: US-2016230532-A1

Title: High Performance Wire Marking for Downhole Cables

Description:
FIELD OF THE INVENTION 
     The present disclosure relates generally to system and methods for marking cables to be deployed within a borehole, and more particularly to systems and methods that involve the use of a cable having markings indicative of marking data that can be read by a reader and transmitted to a controller to convey information about the cable. 
     DESCRIPTION OF RELATED ART 
     Wells are drilled at various depths to access and produce oil, gas, minerals, and other naturally-occurring deposits from subterranean geological formations. The drilling of a well is typically accomplished with a drill bit that is rotated within the well to advance the well by removing topsoil, sand, clay, limestone, calcites, dolomites, or other materials. The drill bit is typically attached to a drill string that may be rotated to drive the drill bit and within which drilling fluid, referred to as “drilling mud” or “mud”, may be delivered downhole. The drilling mud is used to cool and lubricate the drill bit and downhole equipment and, as such, is circulated through the drill string and back to the surface in an annulus formed by the space between the drill string and wall of the well bore. 
     In addition to a drill string, other conveyances may also be used to deploy tools and equipment in a well. Such other conveyances may include wireline and slickline cables used to lower tools into wells for well intervention, logging efforts, and pipe recovery. Generally, slickline deployments involve the use of non-electric cables used to install or remove tools from a well, while wireline deployments typically involve the use of electric cables that are operable to transmit power and data to and from tools in a well. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic, front view of a well that includes a system for reading marking data from a drill string and transmitting the marking data to a controller; 
         FIG. 2  is a schematic, front view of a subsea well that includes the system for reading marking data from a drill string and transmitting the marking data to a controller; 
         FIG. 3  is a schematic, front view of wireline tool being deployed in a well that includes the system for reading marking data from a cable and transmitting the read marking data to a controller; and 
         FIG. 4  is a detail view showing a marking and a reader operable to read the marking and transmit marking data to a controller. 
     
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     In the following detailed description of the illustrative embodiments, reference is made to the accompanying drawings that form a part hereof These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is understood that other embodiments may be utilized and that logical structural, mechanical, electrical, and chemical changes may be made without departing from the spirit or scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the embodiments described herein, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the illustrative embodiments is defined only by the appended claims. 
     In the case of wireline and slickline cable deployments as described above, a well operator may employ a system for monitoring a cable being deployed into a borehole. Such a system may include a cable, which may be a braided steel cable or any similar cable type, and which may include cabling to transmit and receive electricity and data to and from downhole tools. In an embodiment, the system includes one or more markings at regular intervals, and such markings may include marking data that is associated with cable data. In an embodiment, the system also includes a controller to receive, store, and transmit marking data, and a reader that is operable to read the markings on the cables and to transmit marking data to the controller. While the markings and marking data are typically described herein with regard to slickline and wireline systems, the concepts may also be employed in a drilling system that includes a drill bit deployed from a drill string to indicate similar types of information about a drill string or segments of drill pipe that make up the drill string. 
     Referring now to the figures,  FIG. 1  shows a drilling system, which may be referred to as a wellbore cable deployment system  100  that includes a marking data subsystem  130  for reading a marking  122  that is applied to a segment of drill pipe included in a drill string  120 . The marking data subsystem  130  includes a reader  126  that is communicatively coupled to a controller  184  by a coupling  182 . While the coupling  182  is shown as a wired coupling, it is noted that the coupling  182  may be any suitable communicative coupling. For example, the coupling  182  may be a wireless coupling formed by a wireless transceiver that is connected to the reader in communication with a second wireless transceiver that is connected to the controller  184  via any suitable wireless communications protocol. In addition, while the reader  126  is shown as being mounted to a linkage of a rig, the reader  126  may instead be a hand-operated reader or a reader that is mounted at any other point in the drilling system along the path of the drill string  120 . 
     The marking data subsystem  130  is used in a well  102  having a borehole  106  that extends from a surface  108  of the well  102  to or through a subterranean formation  112 . The well  102  is illustrated onshore in  FIG. 1  with the markings  122  being applied to multiple segments of the drill string  120 . In an embodiment, a marking  122  is applied to each segment of drill pipe in the drill string  120 . In another embodiment, the marking data subsystem  130  may be deployed in a sub-sea well  119  accessed by a fixed or floating platform  121 , as shown in  FIG. 2 .  FIGS. 1 and 2  each illustrate possible implementations of the marking data subsystem  130 , and while the following description of the marking data subsystem  130  and associated controls focusses primarily on the use of the marking data subsystem  130  with the onshore well  102  of  FIG. 1 , the marking data subsystem  130  may be used instead in the well configuration illustrated in  FIG. 2 , as well as in other well configurations where it is desirable to read and transmit marking data. Similar components in  FIGS. 1 and 2  are identified with similar reference numerals. 
     In  FIG. 1 , the well  102  is formed by a drilling process in which a drill bit  116  is turned by the drill string  120  to remove material from the formation and form the borehole  106 . The drill string  120  extends from the drill bit  116  at the bottom of the borehole  106  to the surface  108  of the well  102 , where it is joined with a kelly  128 . The drill string  120  may be made up of one or more connected tubes or pipes of varying or similar cross-section. A marking  122  may be applied to one or more of such connected tubes or pipes or to each segment of drill pipe. As referenced herein, the drill string  120  may refer to the collection of pipes or tubes as a single component, or alternatively to the individual pipes or tubes that comprise the string. The term drill string is not meant to be limiting in nature and may refer to any component or components that are capable of transferring rotational energy from the surface of the well to the drill bit  116 . The drill string  120  may include a central passage disposed longitudinally in the drill string  120  and capable of allowing fluid communication between the surface  108  of the well and downhole locations. 
     At or near the surface  108  of the well  102 , the drill string  120  is coupled to the kelly  128 . The kelly  128  may have a square, hexagonal or octagonal cross-section. The kelly  128  is connected at one end to the remainder of the drill string  120  and at an opposite end to a rotary swivel  132 . The kelly passes through a rotary table  136  that is capable of rotating the kelly  128  and thus the remainder of the drill string  120  and drill bit  116 . The rotary swivel  132  allows the kelly  128  to rotate without rotational motion being imparted to the rotary cable  139 . A hook  138 , the cable  139 , a traveling block (not shown), and a hoist (not shown) are provided to lift or lower the drill bit  116 , drill string  120 , kelly  128  and rotary swivel  132 . The drill string  120  may be raised or lowered as needed to add additional sections of tubing to the drill string  120  as the drill bit  116  advances, or to remove sections of tubing  126  from the drill string  120  if removal of the drill string  120  and drill bit  116  from the well  102  are not desired. While the rotary table  136  and kelly  128  are described herein as providing the rotational force to turn the drill string  120 , other systems may be used in their place. For example, a top drive assembly having a motor that turns the drill string  120  may be used to form the borehole  106 . 
     A similar system is shown in  FIG. 3 , which illustrates a wireline assembly  200  that includes components that are analogous in some respects to the components referred to above with retarded  FIGS. 1 and 2 . Such analogous components may be referred to by the same reference numeral indexed by  100 . More specifically,  FIG. 3  shows a wireline tool  215  being deployed in a borehole  204  from a wireline cable  220  to gather measurements relating to the properties of a formation  212 . At the surface  208 , the cable  220  is deployed from a spool and winch assembly  217 , which allows the wireline tool  215  to be raised and lowered in the borehole  204  by a hydraulic or manual control system. Like the drill string  120  described with regard to  FIGS. 1 and 2 , the cable  220  includes one or more markings  222  at or near the surface of the cable  220 . 
     While the cable  220  discussed with regard to  FIG. 3  is a wireline cable, the cable may instead be a slickline cable or any other similar cable deployed within a borehole  204 . The cables may be composite cables, composite rods, or coated cables, such as open hole, cased hole, or slickline coated cables. 
     In an embodiment, the markings  222  are applied to the cable  220  at regular intervals or spacings. Such intervals may be preselected distances, which may be regular distances, for example, 1 m, 10 m, 30 m, or any shorter or longer suitable distance. In an embodiment, the intervals may be spaced according to an algorithm or frequency of marking on a spool. For example, the marking  222  may be applied at regular time intervals as the cable  220  is wound about the spool so that each interval corresponds to a rotation of the spool. Where the cable  220  is a coated cable, such as a polymer-coated cable, the marking  222  may be applied outside of the outermost coating layer of the cable  220 . In another embodiment in which the outermost coating layer of the cable  220  is transparent, the marking  222  may be applied to the outermost nontransparent layer, which is subsequently covered and protected by the transparent layer in a way that does not affect readability. 
     The marking  222  may be applied to the cable  220  using any suitable method, such as ring marking, hot foil marking or cladding. Generally, ring marking involves spraying the marking  222  onto the cable as is passed through a pair of rotating wheels as the cable is extruded or coated. Hot foil marking, conversely, involves the use of a heated metal die that presses a pigmented hot foil tape against the layer of cable to be marked. Both ring marking and hot foil marking are suitable for high-speed marking of the cable, allowing for the markings  222  to be very close together if desired. 
     In an embodiment, the marking  222  may be a continuous marking that extends lengthwise along the cable  220 , from end-to-end, allowing a user of the cable  220  to identify and read the marking from an end-on view or a side view of the cable  220 . The marking  222  can be encoded with information based on the number of marks, the widths of the individual marks, and/or the spacing between each mark, similar to a barcode marking. Such a marking  222  may be viewed as a continuous barcode that is integrated into a material or layer of the cable  222 . To fabricate such a cable, the materials that form the marking may be integrated into the cable material and coextruded as the cable or cable casing is formed by pulling a marking  222  into the cable  222  or its casing. 
     Each marking  222  may include marking data. As referenced herein, marking data means data encoded in or associated with a marking  222 . Such data may be visual data that is printed on or embedded in the surface of the cable, including visual data that is encoded as a barcode, ring barcode, quick-response code, alphanumeric sequence, such as a serial number or other unique identifier, or any other suitable visually readable code. As referenced herein, a quick-response code, also referred to as a QR code, is a machine-readable code consisting of an array of black and white squares, that may be associated with stored data. Each marking  222  may be different dependent on the location of the marking  222  relative to an end of the cable  220  or a previous or subsequent marking  222 . 
     The marking data may include a distance from the marking  222  to one or both ends of the cable  220 , to a previous marking  222 , to a subsequent marking  222 , and any combination thereof. In an embodiment, additional data, which may be referred to as cable data, is associated with the marking data in a memory or a database. Such cable data may include specific information about the cable, such as its origin (cable type and manufacturer), age (date of manufacture), mechanical properties (including composition, modulus of deformation, and tensile strength), usage history, total length, the location of a marking relative to other markings, and other data of interest to a well operator. It is noted that any of the cable data may also be included as marking data by including the data in the marking instead of storing the data in a memory or database and correlating it with the marking data. 
     Like the wellbore cable deployment system  100  described with regard to  FIGS. 1 and 2 , the wireline assembly  200  includes a marking data subsystem  230 . In turn, the marking data subsystem  230  includes a reader  226  that is communicatively coupled to a controller  284  by a coupling  282 . While the coupling  282  is shown as a wired coupling, it is noted that the coupling  282  may be any suitable communicative coupling. For example, the coupling  282  may be a wireless coupling formed by a wireless transceiver connected to the reader  226  in communication with a second wireless transceiver that is connected to the controller  284 . 
     The reader  226 , which may be an automated reader, may be any suitable read device that is operable to read a marking or to otherwise receive visual input. In an embodiment, the reader  226  is an optical reader capable of capturing the visual information included in the marking  222  and transforming the visual information to digital information. For example, the reader  226  may be a pen-type stylus having a light source and a photodiode, which is operable to read visual signals detected by the reader  226 . In another embodiment, the reader  226  may be a laser scanner that is similar in functionality to the aforementioned stylus, wherein the reader  226  reads marking data by shining a laser on the marking data and receiving the marking data with a sensor. For example, as shown in  FIG. 4 , a reader  326  includes a laser scanner that distributes a laser  330  over an area of a cable  320  that includes a marking  322 . The marking  322  is a barcode or QR code that is read by the reader  326  from a reflection of the laser  330  by the marking  322 , and transmitted to an operator. 
     Referring again to  FIG. 3 , in another embodiment, the reader  226  may be a CCD or CMOS sensor that is coupled to a computing system to receive and transmit marking data illuminated by ambient light or an artificial light source. In another embodiment, the reader  226  may be camera system that obtains an electronic image of the marking  222  and applies an optical character recognition algorithm to determine the content of the marking  222 . 
     More generally, the reader  226  may include a processor, a sensor, a power source, a memory, and a transceiver. The memory may include instructions for the processor to cause the reader  226  to read the marking  222  and digitize the marking data through any suitable process, such as, for example, optical character recognition. In operation, as a marking  222  passes the reader  226 , the reader  226  reads marking data from the marking  222 , digitizes the marking data, and transmits the marking data to the controller  284 . 
     The controller  284  may be a computer, computing system, personal computing device, or any other suitable controller, and may include a memory, a processor, a power source, and a transceiver. In an embodiment, the memory of the controller  284  may include a database that includes cable data that is associated with the marking data. For example, the database may include cable data consisting of a cable&#39;s type, age, place of origin, usage history, and mechanical properties, and such cable data may be associated with a serial number or other marking data included in the marking  222  in the database. In addition, the controller  284  and reader  226  may be configured to observe the time or distance between each marking  222  as the cable  220  is deployed in the borehole, and to compare the observed time or distance to an expected time or distance to compute the cable strain or load on the cable  220  based on known mechanical properties of the cable  220 . Alternatively, where the cable strain and mechanical properties of the cable  220  are known, the observed time or distance may be used to compute the rate of deployment of the cable  220 . 
     In addition, the marking data may be used by the controller  284  to provide precise depth information that indicates the length of cable  220  that has been deployed past the reader  222  and therefore the depth of the wireline tool  215 . In addition, the marking data or cable data may be used to provide a precise remaining cable length after the cable  220  has been cut. Where the depth of the end of the cable  220  is known, marking data or cable data may be used to calculate cable tension and cable deformation. After the cable  220  has been used and retrieved from the borehole  204 , the markings  222  may be read by a remote reader when there is no load on the cable  220  to determine permanent deformation of the cable  220 , which may be stored or monitored as an indicator of cable wear. In such an embodiment, an operator may compare the measured cable wear to a predetermined amount of acceptable cable wear determined as a function of the permanent deformation of the cable  220 , and if the measured cable wear exceeds the predetermined amount, then the operator may determine that the cable  220  should not be used. 
     The illustrative systems, methods, and devices described herein may also be described by the following examples: 
     Example 1 
     A wellbore cable deployment system for monitoring a cable being deployed to a borehole, the system comprising:
         a downhole cable having a continuous marking or a plurality of markings at regular intervals, such markings including marking data;   a controller operable to receive, store, and transmit marking data; and   a reader operable to read the markings as the downhole cable is deployed and to transmit marking data to the controller.       

     Example 2 
     The system of example 1, wherein the cable comprises a polymer coating having an inner layer and an outer transparent layer, and wherein the inner layer of the polymer coating comprises the marking. 
     Example 3 
     The system of example 1, wherein the marking comprises a member of the group consisting of: alphanumeric characters, bar codes, ring codes, and quick-response code. 
     Example 4 
     The system of example 1, wherein the marking comprises ring marking or hot foil marking. 
     Example 5 
     The system of example 1, wherein the reader comprises a stylus having a light source and a photodiode and the markings comprise optical marks. 
     Example 6 
     The system of example 1, wherein the reader comprises a laser and a photodiode, and wherein the markings comprise optical marks. 
     Example 7 
     The system of example 1, wherein the reader comprises a charge-coupled device operable to read the markings using ambient light. 
     Example 8 
     The system of example 1, wherein the reader comprises a camera system having a processor, a sensor, and a memory, and wherein the memory comprises instructions for reading the markings using optical character recognition. 
     Example 9 
     The system of example 1, wherein the marking data comprises data selected from the group consisting of: the distance between markings, the marking count, a unique identification number, data indicating the material composition of the cable. 
     Example 10 
     The system of example 1, where the controller comprises a database storing cable data, and wherein the marking data is associated with cable data. 
     Example 11 
     The system of example 10, wherein the cable data comprises the usage history of the cable. 
     Example 12 
     A cable for deployment in a borehole, the cable comprising: a continuous marking, such marking including marking data that is associated with cable data. 
     Example 13 
     A cable for deployment in a borehole, the cable comprising: a plurality of markings at regular intervals, such markings including marking data that is associated with cable data. 
     Example 14 
     The cable of examples 12 and 13, wherein each marking is a machine-readable marking that can be read by an automated reader. 
     Example 15 
     The cable of example 12, wherein the cable comprises a polymer coating, and wherein the polymer coating comprises each marking. 
     Example 16 
     The cable of example 13, wherein the markings comprise a member of the group consisting of: alphanumeric characters, bar codes, ring codes, and quick-response code. 
     Example 17 
     The cable of example 13, wherein the markings comprise ring marking or hot foil marking. 
     Example 18 
     The cable of example 13, wherein the cable data comprises data selected from the group consisting of: the distance between markings, the marking count, a unique identification number, data indicating the material composition of the cable. 
     Example 19 
     A method for gathering information about a cable deployed in a borehole, the method comprising:
         reading at least one marking from a cable, such marking including marking data that is associated with cable data;   transmitting the marking data to a control system, the control system having a memory, a processor, and a transceiver;   receiving the marking data at the control system.       

     Example 20 
     The method of example 19, wherein reading at least one marking comprises using a pen-type stylus having a light source and a photodiode to detect the markings, the markings comprising optical marks. 
     Example 21 
     The method of example 19, wherein reading at least one marking comprises using a laser scanner having a laser light source and a photodiode to detect the markings, the markings comprising optical marks. 
     Example 22 
     The method of example 19, wherein reading at least one marking comprises using a charge-coupled device to read the markings in ambient light. 
     Example 23 
     The method of example 19, wherein reading at least one marking comprises using a camera system having a processor, a sensor, and a memory, wherein the memory comprises instructions for reading the markings using optical character recognition. 
     Example 24 
     The method of example 19, further comprising tracking a length of cable that has entered the well based on marking data from the read markings. 
     Example 25 
     The method of example 19, further comprising tracking a length of cable that has entered the well based on the number of read markings. 
     Example 26 
     The method of example 19, further comprising determining a cable tension based on marking data from the read markings. 
     Example 27 
     The method of example 19, further comprising determining cable deformation based on marking data from the read markings. 
     Example 28 
     The method of example 19, further comprising determining permanent cable deformation based on marking data from the read marking, comparing the permanent cable deformation to an acceptable amount of permanent cable deformation, and determining whether the cable is suitable for continued use based on whether the data and permanent cable deformation exceeds the acceptable amount of permanent cable deformation. 
     It should be apparent from the foregoing that an invention having significant advantages has been provided. While the invention is shown in only a few of its forms, it is not limited to only these embodiments but is susceptible to various changes and modifications without departing from the spirit thereof.