Patent Publication Number: US-9416596-B2

Title: Installation of lines in high temperature wellbore environments

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 USC §119 of the filing date of International Application Serial No. PCT/US10/38651 filed 15 Jun. 2010. The entire disclosure of this prior application is incorporated herein by this reference. 
     BACKGROUND 
     The present disclosure relates generally to equipment and operations utilized in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides for installation of lines in high temperature wellbore environments. 
     It is known to extend various types of lines (such as hydraulic, electrical and/or fiber optic lines) through packers in subterranean wells. However, the lines are typically rigidly attached to the packers and/or other components of a tubular string. 
     The packer attachments typically require splicing the lines, or at least making connections in the lines. In high temperature environments (such as steam injection completions, very deep wellbores, etc.), the tubular string will expand, and so a travel joint is generally used to absorb this expansion. 
     It will be appreciated that improvements are needed in the art of securing lines to tubular strings in high temperature wellbore environments. These improvements could include elimination of the need for a travel joint, elimination of the need for making splices and connections in the lines, and/or elimination of the need for a packer to restrict fluid flow through an annulus. 
     SUMMARY 
     In carrying out the principles of the present disclosure, apparatus, systems and methods are provided which bring improvements to the art of installation of lines in high temperature wellbore environments. One example is described below in which lines are secured in an annular restrictor without splicing or making connections in the lines. Another example is described below in which the annular restrictor is used between steam injection valves in a well completion. 
     In one aspect, an annular restrictor for use in a subterranean well is provided to the art by the present disclosure. The annular restrictor can include a body which extends circumferentially about a tubular mandrel, and a section which, in cooperation with the body, restricts fluid flow through an annulus in the well. At least one line is secured between the body and the section. 
     In another aspect, a method of completing a subterranean well is provided. The method can include installing at least one line in an annular restrictor, and restricting fluid flow through an annulus formed radially between a tubular string and a wellbore. The restricting is performed by the annular restrictor interconnected between steam injection valves. 
     In yet another aspect, a method of attaching at least one line to a tubular string for use in a subterranean well can include: covering the line with a section of an annular restrictor, and securing the section to a body of the annular restrictor. Each of the section and the body has a flow restricting surface formed thereon. The covering and securing steps are performed without splicing or making a connection in the line. 
     These and other features, advantages and benefits will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments of the disclosure hereinbelow and the accompanying drawings, in which similar elements are indicated in the various figures using the same reference numbers. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic partially cross-sectional view of a well system and method which can embody principles of the present disclosure. 
         FIG. 2A  is a schematic elevational view of annular restrictors and centralizers which may be used in the system and method of  FIG. 1 . 
         FIG. 2B  is a schematic vertical cross-sectional view of the annular restrictors and centralizers of  FIG. 2A . 
         FIG. 3  is a schematic orthogonal exploded view of one of the annular restrictors. 
         FIG. 4  is a schematic orthogonal view of one of the centralizers. 
     
    
    
     DETAILED DESCRIPTION 
     Representatively illustrated in  FIG. 1  is a well system  10  and associated method which can embody principles of the present disclosure. In the system  10 , a tubular string  12  in installed in a well bore  14 . 
     In this example, the bore  14  is formed in a slotted liner  16  installed in an otherwise open wellbore  18 . However, in other examples, the slotted liner  16  may not be used or may be replaced by casing, etc. Thus, the bore  14  could be formed in a tubular structure (such as in casing liner, tubing, etc.), or the bore could be formed by the wall of the wellbore  18 , in other embodiments. 
     As depicted in  FIG. 1 , annular restrictors  20 , centralizers  22 , steam injection valves  24  and instrument carriers  26  are interconnected in the tubular string  12 . Steam  28  is injected via the valves  24  into a formation  30 , in order to mobilize hydrocarbon fluids  32  in the formation, and allow the fluids to drain into another wellbore  34  drilled into the formation. 
     Thus, the well system  10  is of the type known to those skilled in the art as steam assisted gravity drainage (SAGD). However, it should be clearly understood that the principles of this disclosure are not limited to use only in steam assisted gravity drainage well systems. 
     Various lines  36  are connected to the steam injection valves  24  and instrument carriers  26 . The lines  36  can include hydraulic, electrical and/or optical lines for actuating the valves  24 , transmitting sensor data from the instrument carriers  26 , transmitting command and control signals, etc. 
     The lines  36  can also be used for sensing purposes (for example, in optical distributed temperature, acoustic and/or strain sensing, etc.). The lines  36  may be used for any purposes in keeping with the principles of this disclosure. 
     In the lower wellbore  34 , a tubular string  38  is installed, with packers  40  and production valves  42  interconnected therein. Note that, the annular restrictors  20  could be used in place of the packers  40 , if desired, and so it will be appreciated that the principles of this disclosure are not limited to use in an injection operation, but can also be used in production operations, and/or in any other types of well operations. The steam injection valves  24  could also, or alternatively, be used for the production valves  42 . 
     The annular restrictors  20  restrict fluid flow through an annulus  44  formed radially between the tubular string  12  and the well bore  14 . The annular restrictors  20  do not necessarily seal off the annulus  44 , but in other examples the annular restrictors could completely seal off the annulus to thereby prevent fluid flow through the annulus. As used herein, the term “restricts,” “restricting,” and similar terms encompass both non-sealing and sealing. 
     The centralizers  22  help to prevent damage to the annular restrictors  20  during installation of the tubular string  12  in the well bore  14 . The lines  36  extend longitudinally through the annular restrictors  20  and centralizers  22  in a manner which permits some longitudinal displacement of the lines relative to the tubular string  12 , and which eliminates the need for making splices and/or connections in the lines, as described more fully below. 
     Referring additionally now to  FIGS. 2A  &amp; B, enlarged scale views of the annular restrictors  20  and centralizers  22  are representatively illustrated. In these more detailed views, it may be seen that the centralizers  22  are preferably interconnected in the tubular string  12  so that they straddle the annular restrictors  20 . 
     In this example, the centralizers  22  have somewhat larger outer diameters than the annular restrictors  20 , in order to protect the annular restrictors from damage during installation. However, in other examples the centralizers  22  may not have larger outer diameters than the annular restrictors  20 . 
     As depicted in  FIGS. 2A  &amp; B, two of the annular restrictors  20  are interconnected between two of the centralizers  22 . The annular restrictors  20  are somewhat similar to “cup” packers, in that they are cup-shaped and, in this example, the open cup end of each annular restrictor faces outwardly (e.g., longitudinally away from the other annular restrictor), so that the annular restrictors effectively restrict fluid flow from either longitudinal direction. 
     Each annular restrictor  20  includes a body  46 , a section  48  which removes from the body for installation of the lines  36  (not shown in  FIGS. 2A  &amp; B), and a clamp  50 . The body  46 , section  48  and clamp  50  are carried on a tubular mandrel  52 . 
     One advantage of using the annular restrictors  20  is that they allow for elongation and contraction of the tubular string  12  with thermal changes (i.e., the tubular string can displace relative to the well bore  14 ), without the need for travel joints. Unlike a packer which grips a wellbore wall, the annular restrictors  20  do not rigidly secure the tubular string  12  to the well bore  14 . 
     Referring additionally now to  FIG. 3 , an enlarged scale exploded view of an annular restrictor  20  is representatively illustrated, apart from the remainder of the well system  10 . In this view, it may be clearly seen that the section  48  can be removed from the body  46  to expose line-receiving recesses  54  formed in the body. 
     With the lines  36  received in the recesses  54 , the section  48  can be secured to the body  46  using the clamp  50   a,b  to thereby secure the lines to the tubular string  12 , without the need for making splices or other connections in the lines. In some embodiments, the lines  36  could also displace longitudinally through the recesses  54  if needed when the tubular string  12  expands or contracts. 
     Note that, although not visible in  FIG. 3 , the recesses  54  can also be formed on an inner surface of the section  48  (see  FIG. 2B ). 
     When the section  48  is appropriately secured to the body  46 , a continuous (or at least substantially continuous) circumferential flow restricting surface  56  is formed on each of the body and the section. The surface  56  may be spaced apart from the well bore  14  by the centralizers  22  or, in other examples, the surface could sealingly engage the well bore to thereby completely prevent fluid flow through the annulus  44 . 
     In a preferred embodiment, the body  46  and section  48  are constructed of 40% glass fiber filled PTFE (polytetrafluoroethylene) for high temperature durability. However, other materials may be used, if desired. 
     Note that the annular restrictor  20  could be used in well systems in which the lines  36  are not also used, or in which the lines do not extend through the annular restrictor. In those situations, the separate section  48  would not necessarily be used, but instead the section could be integrally formed with the body  46 , and the recesses  54  would either not be used, or would be plugged. 
     Referring additionally now to  FIG. 4 , an enlarged scale view of a centralizer  22  is representatively illustrated. In this view, it may be clearly seen that the centralizer  22  includes a generally tubular housing  58  with a radially enlarged centralizing structure  60  having a series of longitudinally extending line-receiving slots  62  formed therein. 
     Clamps  64  are used to secure the lines  36  in the slots  62 . Preferably, the clamps  64  are recessed somewhat relative to the outer surface of the centralizing structure  60 , so that they are not subject to impacts and wear during installation. 
     It may now be fully appreciated that several advancements are provided to the art by the above disclosure. In particular, the lines  36  can be secured to the tubular string  12  as the tubular string is installed in the well, without the need for making splices and/or other connections in the lines. The annular restrictors  20  substantially restrict fluid flow through the annulus  44  (thereby allowing for control over the amount of steam  28  injected into each zone or section of the formation  30 ), and secure the lines  36  to the tubular string  12 , while also allowing for relative displacement between the tubular string and the well bore  14 . 
     The above disclosure provides to the art an annular restrictor  20  for use in a subterranean well. The annular restrictor  20  can include a body  46  which extends circumferentially about a tubular mandrel  52 , and a section  48  which, in cooperation with the body  46 , restricts fluid flow through an annulus  44  in the well. At least one line  36  is secured between the body  46  and the section  48 . 
     At least one line-receiving recess  54  may be formed on the body  46  and/or the section  48 . The line-receiving recess  54  can be formed on both of the body  46  and the section  48 . 
     The annular restrictor  20  can also include a clamp  50  which secures the section  48  to the body  46 . 
     The body  46  and section  48  can form a cup shape. 
     Each of the body  46  and the section  48  can include a flow restricting surface  56 . 
     Also described by the above disclosure is a method of completing a subterranean well. The method can include: installing at least one line  36  in an annular restrictor  20 ; and restricting fluid flow through an annulus  44  formed radially between a tubular string  12  and a well bore  14 , with the restricting being performed by the annular restrictor  20  interconnected between steam injection valves  24 . 
     The line  36  may be operatively connected to at least one of the steam injection valves  24 . 
     The installing step can be performed without splicing the line  36 . The installing step can be performed without making a connection in the line  36 . 
     The installing step can be performed by securing the line  36  between a body  46  of the annular restrictor  20  and a section  48  of the annular restrictor  20 . The section  48  may cooperate with the body  46  in restricting fluid flow through the annulus  44 . 
     The above disclosure also describes a method of attaching at least one line  36  to a tubular string  12  for use in a subterranean well, with the method comprising: covering the line  36  with a section  48  of an annular restrictor  20 ; and securing the section  48  to a body  46  of the annular restrictor  20 . Each of the section  48  and the body  46  has a flow restricting surface  56  formed thereon. The covering and securing steps are performed without splicing or making a connection in the line  36 . 
     The annular restrictor  20  may be interconnected between steam injection valves  24 . 
     The tubular string  12  may be free to displace longitudinally relative to the well bore  14  while the annular restrictor  20  restricts fluid flow through an annulus  44  formed radially between the tubular string  12  and the well bore  14 . 
     It is to be understood that the various embodiments of the present disclosure described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of the present disclosure. The embodiments are described merely as examples of useful applications of the principles of the disclosure, which is not limited to any specific details of these embodiments. 
     In the above description of the representative embodiments of the disclosure, directional terms, such as “above,” “below,” “upper,” “lower,” etc., are used only for convenience in referring to the accompanying drawings. 
     Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the disclosure, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to the specific embodiments, and such changes are contemplated by the principles of the present disclosure. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims and their equivalents.