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CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of an earlier filing date from U.S. Provisional Application Ser. No. 61/234,471 filed Aug. 17, 2009, the entire disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    In the drilling and completion arts, lengths of tubing known as a string is installed for various purposes such as drilling, injection, production, etc. The art in more recent years has become increasingly interested in monitoring and control of devices in the downhole environment. To accommodate this interest, lines such as fiber optic lines, electric lines, hydraulic lines, etc are installed adjacent the string. The lines may be installed in a number of positions relative to the string such as at the inside dimension of the string, somewhere within various concentric layers of the string or outside of the string, for example, on a surface thereof or spaced therefrom. Depending upon where the lines are run, they may or may not be subject to mechanically inflicted damage during running of the string in the hole. While various methods are known to protect lines at the outside dimension of the string such as channels, grooves, etc. the art is still interested in alternative means for protecting the lines that provides good protection at rapid speed and with minimal complexity of installation. 
       SUMMARY 
       [0003]    A downhole apparatus includes a tubular and at least one line passage extending along an outer surface of the tubular. At least one end clamp is located at least one end of the line passage. The at least one end clamp includes a clamp body and at least one standoff located between the clamp body and the outer surface of the tubular defining a clamp protected space therebetween. 
         [0004]    A downhole tubular system includes a least two tubular apparatus, each tubular apparatus including at least one tubular and at least one line passage extending along an outer surface of the tubular. At least one end clamp is located at least one end of the line passage. The at least one end clamp includes a clamp body; and at least one standoff located between the clamp body and the outer surface of the tubular defining a clamp protected space therebetween. The tubular system further includes at least one coupling clamp disposed at a coupling of the at least two tubular apparatus. The at least one coupling clamp includes at least two collars wherein at least one collar of the at least two collars is located at each side of the coupling. Each collar includes a coupling body extending around a circumference of the outer surface defining a coupling protected space between the coupling body and the outer surface. A coupling sleeve extends between the at least two collars. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    Referring now to the drawings wherein like elements are numbered alike in the several Figures: 
           [0006]      FIG. 1  is a perspective view of an embodiment of a downhole tubular apparatus; 
           [0007]      FIG. 2  is a perspective view of a joining mechanism between two line passages of an embodiment of a downhole apparatus; 
           [0008]      FIG. 3  is an embodiment of an end clamp for an embodiment of a downhole apparatus; 
           [0009]      FIG. 4  is a cross sectional view of an embodiment of an end clamp; 
           [0010]      FIG. 5  is an embodiment of a cross-coupling clamp of a downhole apparatus; and 
           [0011]      FIG. 6  is a cross sectional view of an embodiment of a cross-coupling clamp. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    Shown in  FIG. 1  a portion of a string  10 . The string  10  is a length of tubing installed in a downhole environment for various purposes such as drilling, injection and/or production. The string  10  includes a plurality of centralizers  12  which extend outwardly from an outer surface  14  of the string  10  to prevent damage to the string  10  when the string  10  is run into or removed from the downhole environment. The plurality of centralizers  12  are disposed along a length of the string  10  and also around a perimeter of the string  10 . The plurality of centralizers  12  may be secured to the string  10  by any conventional means, including welding and/or one or more mechanical fasteners such as bolts, or may be formed integral to the string  10 . While the embodiment shown in  FIG. 1  includes a plurality of centralizers  12 , it is to be appreciated that in some embodiments, centralizers  12  may be absent from the string  10 . 
         [0013]    To monitor and/or control one or more devices downhole, one or more monitoring or control lines  16  extend along the outer surface  14  of the string  10 . The lines may be, for example, electrical lines, hydraulic lines, and/or fiber optic lines, or the like. Further, while four lines  16  are shown in  FIG. 1 , it is to be appreciated that other quantities of lines  16 , for example one, two, or ten lines  16  are contemplated herein. 
         [0014]    To protect the lines  16  along the string  10 , at least one line passage  18  is disposed along the outer surface  14  of the string  10  and extending axially along the string  10 . In some embodiments, the at least one line passage  18  may be disposed circumferentially between two centralizers  12 . The at least one line passage  18  may have a tubular cross section and in some embodiments may be curved in a circumferential direction to, for example, match a curvature of the string  10 . In some embodiments, the at least one line passage  18  cross section is a unitary piece. The one or more lines  16  extend through the at least one line passage  18  and are protected therein from damage. 
         [0015]    In some embodiments, the at least one line passage  18  extends substantially an entire length of a joint of the string  10 . In other embodiments, however, it may be desired to utilize two or more interconnected line passages  18  arranged axially along the string  10 . In one embodiment, each line passage  18  will extend about 10 feet. Referring to  FIG. 2 , a first line passage  18  may interconnect to a second line passage  18  via, for example, a pin and sleeve arrangement. The first line passage  18  may include a sleeve  20  at one circumferential side and a pin  22  at the other circumferential side, while the second line passage  18  may similarly include a sleeve  20  and a pin  22 . The pin  22  of the first line passage  18  is engaged in the sleeve  20  of second line passage  18  and the pin  22  of the second line passage  18  is inserted into the sleeve  20  of the first line passage  18 . Alternatively, the first line passage  18  may be configured entirely with pins  22  and the second line passage  18  may be configured entirely with sleeves  20 , or vice versa. While the pin and sleeve arrangement is illustrated in  FIG. 2 , it is to be appreciated that other means of interconnecting or joining the line passages  18  may be utilized. For example, the line passages  18  may be interconnected utilizing hinges, a telescoping overlap between the ends of the two line passages  18 , and/or bolts. Further, while a single connection between two line passages  18  is shown, other quantities of line passages  18 , for example, three or five line passages  18  may be arranged along each joint of the string  10 . 
         [0016]    To secure the lines  16  at each end  24  of each joint of string  10 , an end clamp  26  is utilized. Referring to  FIG. 3 , the end clamp  26  extends around the circumference of the string  10  and secures the lines  16  thereto. Referring to  FIG. 4 , the end clamp  26  includes two clamp hinges  28  configured to rest on the outer surface  14  of the string  10  when the end clamp  26  is installed. The clamp hinges  28  act as spacers to define a clamp protected space  30  between a clamp body  32  disposed between the clamp hinges  28  and the outer surface  14 . The clamp protected space  30  in some embodiments may be substantially equal to a thickness of the lines  16  to secure the lines  16  therein when the end clamp  26  is secured. The end clamp  26  includes two clamp arms  34 , one clamp arm  34  extending from each clamp hinge  28 . Each clamp arm  34  includes a plurality of fingers  36  configured to interlock with fingers  36  of the other clamp arm  34  when the end clamp  26  is closed around the string  10 . With the fingers  36  interlocked, the end clamp  26  is secured in the closed position by, for example, a clamp pin  38  installed through a plurality of pin holes  40  in the plurality of fingers  36  to prevent the end clamp  26  from opening unexpectedly. While the embodiment is shown with two clamp hinges  28 , other quantities of clamp hinges  28  may be utilized. Further, additional spacers may be utilized to define the clamp protected space  30 . 
         [0017]    Referring again to  FIG. 3 , in some embodiments, the clamp body  32  may include a transition passage  42  to protect the lines  16  at the string  10  portion between an adjacent line passage  18  and the end clamp  26 . The transition passage  42  may be tubular in cross-section to match the line passage  18  and to protect the lines  16  between the line passage  18  and the end clamp  26 . The transition passage  42  may further include a sloping portion  44  or other shape to account for any changes in diameter of the string  10  between the line passage  18  and the end clamp  26 . Further, the transition passage  42  may be joined to the line passage  18  via the pin and sleeve arrangement described above or alternatively via hinges, a telescoping overlap between the end of the line passage  18  and the transition passage  42 , and/or bolts. 
         [0018]    In some embodiments, it is desirable to have lines  16  installed along the length of the string  10 , across couplings of adjacent joints of the string  10 . Referring to  FIG. 5 , a cross-coupling clamp  46  may be disposed at the coupling of two joints of string  10 . The cross-coupling clamp  46  axially overlaps each joint of string  10  and circumferentially surrounds the string  10 . The cross-coupling clamp  46  includes a collar  48  disposed at each end and a sleeve  50  extending axially between the two collars  48  across a coupling between the joints of the string  10 . Referring to  FIG. 6 , each collar  48  includes at least one coupling hinge  52  and two coupling arms  54  extending from the coupling hinge  52 . Each coupling arm  54  may include at least one coupling spacer  56  that, when the collar  48  is closed around the string  10  defines a coupling protected space  58  between the outer surface  14  and the coupling arm  54 . The size of coupling spacer  56  used determines a height of the coupling protected space  58 , and different sized coupling spacers  56  may be utilized depending on a size of lines  16  and/or desired height of the coupling protected space  58 . In some embodiments, the coupling protected space  58  height is greater than a thickness of lines  16  that are disposed in the coupling protected space  58 . This provides a coupling protected space  58  that extends around the circumference of the string  10  and allows for a helical arrangement of the lines  16  in the coupling protected space  58  to, for example, compensate for any variation in circumferential alignment of adjacent string joints  10  at the coupling. Referring again to  FIG. 5 , each coupling arm  54  includes a plurality of coupling fingers  60  configured to interlock with coupling fingers  60  of the other coupling arm  54  when the collar  48  is closed around the string  10 . With the coupling fingers  60  interlocked, the cross-coupling clamp  46  is secured in the closed position by, for example, a coupling pin (not shown) installed through a plurality of coupling finger holes (not shown) in the plurality of coupling fingers  60  to prevent the cross-coupling clamp  46  from opening unexpectedly. 
         [0019]    Referring again to  FIG. 1 , in some embodiments, the string  10  includes a screen  62  at the outer surface  14  to filter flow entering the string  10  for undesired materials. In some embodiments, the outer surface  14  may be a flow through tubular  64  having a line  16  attached thereto. The line  16  attached to the flow through tubular  64  may be a control line or monitoring line that is, for example, an electric line, hydraulic line, fiber optic line or the like. 
         [0020]    While one or more embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.

Summary:
Disclosed is a downhole apparatus including a tubular and at least one line passage extending along an outer surface of the tubular. At least one end clamp is located at least one end of the line passage. The at least one end clamp includes a clamp body and at least one standoff located between the clamp body and the outer surface of the tubular defining a clamp protected space therebetween. Further disclosed is a downhole tubular system including a least two tubular apparatus, each tubular apparatus including at least one tubular and at least one line passage extending along an outer surface of the tubular. At least one end clamp is located at least one end of the line passage. The tubular system further includes at least one coupling clamp disposed at a coupling of the at least two tubular apparatus.