Patent Publication Number: US-8969728-B2

Title: Smooth wireline

Description:
BACKGROUND 
     Wireline equipment used to investigate boreholes and surrounding formations are typically lowered into a well borehole using a cable. In some cases, such as in a gas well, the cable holding the wireline equipment passes through a seal at the surface. The seal allows the cable to move while maintaining gas and/or well pressure within the borehole. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a drilling rig site showing a logging tool that is suspended from a wireline and disposed internally of a bore hole. 
         FIG. 2  is a cross-sectional view of a cable and a seal. 
         FIG. 3  is a perspective view of a cable. 
         FIGS. 4 and 5  are cross-sectional views of cables. 
         FIG. 6  illustrates a remote real time operating center. 
     
    
    
     DETAILED DESCRIPTION 
     In one embodiment of a wireline well logging system  100  at a drilling rig site, as depicted in  FIG. 1 , a logging truck or skid  102  on the earth&#39;s surface  104  houses a data gathering computer  106  and a winch  108  from which a wireline cable  110  extends through a sealing apparatus  111  into a well bore  112  drilled into a hydrocarbon bearing formation  114 . In one embodiment, the wireline cable  110  suspends a logging toolstring  116  within the well bore  112  to measure formation data as the logging tool  116  is raised or lowered by the wireline  110 . In one embodiment, the logging toolstring  116  includes a z-axis accelerometer  118  and several devices A, B, C. In different embodiment, these devices are instruments, mechanical devices, and/or explosive devices. 
     In one embodiment, the wireline cable  110  not only conveys the logging toolstring  116  into the well, it also provides a link for power and communications between the surface equipment and the logging toolstring. 
     In one embodiment, as the logging tool  116  is raised or lowered within the well bore  112 , a depth encoder  122  provides a measured depth of the extended cable. In one embodiment, a tension load cell  124  measures tension in the wireline  110  at the surface  104 . 
     A more detailed view of one embodiment of the sealing apparatus  111 , shown in  FIG. 2 , shows the presence of an aperture  205  through which the wireline cable  110  passes. It should be noted that many details of the sealing apparatus are not shown in  FIG. 2 . 
       FIG. 2  also illustrates a prior art version of a wireline cable  111 , which includes a conductor or conductors  210 , a inner set of armor wires  215  (only one is referenced) and an outer set of armor wires  220  (only one is referenced). Note that the gap between the wireline cable  111  and the boundary of the aperture  205  in the sealing apparatus  111  is exaggerated for purposes of explanation. 
     Typically, as illustrated in  FIG. 2 , the wireline cable  111  is a braided cable and the inner armor wires  215  and outer armor wires  220  are round. Such a design leaves voids, e.g., such as the void  225  between the wireline cable  110  and the boundary of the aperture  205  and the void  230  between the inner set of armor wires  215  and the outer set of armor wires  220 . In one embodiment, one of the goals in designing wireline systems is limiting the size of the voids because such voids are challenging to seal. Typically, such considerations limit the outside diameter of the cable that can be used under pressure. This is because, typically, as the outside diameter of the wireline cable  111  increases, the outside diameter of the outer set of armor wires  220  also increases, which also tends to increase the size of the outer voids, e.g.,  225 , and the inner voids, e.g.  230 . Further, the braided cable design tends to increase friction with the aperture and creates environmental concerns when grease used to seal the outer voids, e.g.,  225 , is lost. 
       FIGS. 3-5  illustrate a wireline cable with shaped inner and outer armor wires, which when assembled provides a nearly smooth outer surface. In one embodiment, this allows the wireline cable to have a larger outside diameter, which will result in greater effective pull at the cable head. In one embodiment, the smooth cable finish also reduces friction between the cable and the boundary of the aperture  205  and allows for greater sealing and pressure control efficiency. In one embodiment, the configurations shown in  FIGS. 3-5  contain more metal in the same outside diameter than traditional wireline cables, which results in greater strength. 
     One embodiment of a wireline cable  305  includes a conductor package  310 . In one embodiment, the conductor package  310  can include any number of conductors of any type. For example, the conductor package can include solid conductors, coaxial conductors, fiber optic conductors, etc. The conductor package can include multi-conductor cables such as seven conductor, crush resistant  7  conductor packages enclosed in a jacket material, single conductor, single fiber optic, fiber optic with one or more conductors, multi-fiber fiber optics, or any other combination. In one embodiment, the conductor package includes strengtheners or load bearing elements to provide strength and stability to the conductor package  310 . In one embodiment, the conductors in the conductor package carry electrical power or communications and/or control signals. 
     In one embodiment, an inner set of armor wires  315  is wrapped around the conductor package  310 . Note that only one wire of the inner set of armor wires  315  is shown. The inner set of armor wires is wrapped in a substantially helical pattern. The use of the word helical in this description is not meant to limit the path of the inner set of armor wires  315  to follow the path of a strictly mathematical helical shape. In one embodiment, the path of each wire of the inner set of armor wires  320  deviates but generally follows the mathematical helical pattern. 
     In one embodiment, an outer set of armor wires  320  is wrapped around the conductor package  310  and the inner set of armor wires  315 . Note that only one wire of the outer set of armor wires  320  is shown. The outer set of armor wires is wrapped in a substantially helical pattern. The use of the word helical in this description is not meant to limit the path of the outer set of armor wires  320  to follow the path of a strictly mathematical helical shape. In one embodiment, the path of each wire of the outer set of armor wires  320  deviates but generally follows the mathematical helical pattern. 
     For the purposes of this application, a helix can be either a right-handed helix or a left-handed helix. For the purposes of this application, a right-handed helical pattern progresses in a clockwise fashion as it recedes from the observer. For the purposes of this application, a left-handed helical pattern progresses in a counter-clockwise fashion as it recedes from the observer. 
     In one embodiment, the outer set of armor wires  320  generally follows a first-handed helical pattern and the inner set of armor wires  315  generally follows a second-handed helical pattern with the observer positioned at the left side of  FIG. 3 . In one embodiment, the first-handed helical pattern is a right-handed helical pattern and the second-handed helical pattern is a left-handed helical pattern. In one embodiment, the first-handed helical pattern is a left-handed helical pattern and the second-handed helical pattern is a right-handed helical pattern. In one embodiment, the first-handed helical pattern is a right-handed helical pattern and the second-handed helical pattern is a right-handed helical pattern. In one embodiment, the first-handed helical pattern is a left-handed helical pattern and the second-handed helical pattern is a left-handed helical pattern. 
     In one embodiment, the shapes of the armor wires are chosen so that when the inner set of armor wires  315  and the outer set of armor wires  320  are laid together, the exterior surface is nearly smooth. In one embodiment, the armor wires are designed without square corners, which means that some voids, albeit smaller as compared to the typical round armor wire design, remain. Once assembled, the design of the armor allows the armor wires to move independently of one another and retain the cable shape upon reforming their original shape if they become temporarily opened or spread apart. 
     In one embodiment, the inner set of armor wires  315  includes at least some armor wires that have non-circular and non-rectangular cross-sectional shapes. In one embodiment, the outer set of armor wires includes at least some armor wires that have non-circular and non-rectangular cross-sectional shapes. In one embodiment, the inner armor wires that have non-circular and non-rectangular cross-sectional shapes have the same cross-sectional shapes, although, in one embodiment, different in size and orientation, as the outer armor wires with non-circular and non-rectangular cross-sectional shapes. 
     One embodiment of such a wireline cable, illustrated in cross-section in  FIG. 4 , includes a conductor package consisting of a single conductor  405  covered by a jacket of insulation  410 . The cross-sections of the inner armor wires  415  (only one is designated) have an S shape. The cross-sections of the outer armor wires  420  (only one is designated) also have an S shape, although the S shape is generally the minor image of and larger than the S shape of the inner armor wires. 
     Another embodiment of such a wireline cable, illustrated in cross-section in  FIG. 5 , includes a conductor package consisting of a single conductor  505  covered by a jacket of insulation  510 . The cross-sections of the inner armor wires  515  (only one is designated) have curved disc shape. The cross-sections of the outer armor wires  520  (only one is designated) also have a curved disc shape, although the curved disc shape is generally the minor image of and larger than the curved disc shape of the inner armor wires. 
     In one embodiment, the shaping of the armor is done during pulling of the wire to size by pulling the wire through a shaper. In one embodiment, the shaping of the wire is done using a technique designed for nano technology where the wires are shaved to increase the alignment of metal crystals and to improve the metal characteristics and strength resulting in a stronger wireline. 
     In one embodiment, a computer program for controlling the operation of the wireline logging system  100  is stored on a computer readable media  605 , such as a CD or DVD, as shown in  FIG. 6 . In one embodiment a computer  610 , which may be the same as data gather computer  106  or which may be below the surface in the well logging toolstring  116 , reads the computer program from the computer readable media  605  through an input/output device  615  and stores it in a memory  620  where it is prepared for execution through compiling and linking, if necessary, and then executed. In one embodiment, the system accepts inputs through an input/output device  615 , such as a keyboard, and provides outputs through an input/output device  615 , such as a monitor or printer. In one embodiment, the system stores the results of calculations in memory  620  or modifies such calculations that already exist in memory  620 . 
     In one embodiment, the results of calculations that reside in memory  620  are made available through a network  625  to a remote real time operating center  630 . In one embodiment, the remote real time operating center  630  makes the results of calculations available through a network  635  to help in the planning of oil wells  640  or in the drilling of oil wells  640 . Similarly, in one embodiment, the wireline logging system  100  can be controlled from the remote real time operating center  630 . 
     The word “couple” or “coupling” as used herein shall mean an electrical, electromagnetic, or mechanical connection and a direct or indirect connection. 
     The cable described herein can also be used in any measurement while drilling (“MWD”), logging while drilling (“LWD”), wired drillpipe, or coiled tubing (wired or unwired) in which a cable is used. 
     In addition to power being provided from the surface through wireline cable  111 , power may also be provided by a battery located in the wireline logging toolstring  116 . 
     The text above describes one or more specific embodiments of a broader invention. The invention also is carried out in a variety of alternate embodiments and thus is not limited to those described here. The foregoing description of the preferred embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.