Patent Abstract:
A protective sleeve can be inserted through tubing and latched in a manner that resists rotation. At the conclusion of the through tubing operation that involves rotational movement, the sleeve is withdrawn on the string that previously extended through it.

Full Description:
PRIORITY INFORMATION 
   This application claims the benefit of U.S. Provisional Application No. 60/539,396, filed on Jan. 27, 2004. 

   FIELD OF THE INVENTION 
   The field of the invention is protection devices for seal bores or other sensitive areas in tubing through which drilling or other completion procedures that involve rotation take place. 
   BACKGROUND OF THE INVENTION 
   Tubular strings now experience rotational movement of a through tubing drill string. Other completion operations could also involve rotation. Many types of devices that are part of the tubular string have internal seal bores or other sensitive areas that can be damaged by the whip action of the through tubing rotating string. In the past, various solutions have been attempted. In one design, the seal bores are recessed so that the whip motion of the string or the running in and out of the hole on a wireline does not damage the recessed seal bore. An example of such a design is U.S. Pat. No. 5,865,255. Recessing the seal bore then requires equipment able to spread the seals of subsequent equipment introduced into the tubing and designed to seal against the seal bore. 
   Protective sleeves have been tried to overlay the seal bore but the problem with them was that they were not rotationally locked and the whip action of the through tubing drill string making contact with such a protective sleeve, either eroded it away by spinning it or got the protective sleeve so hot from rotation that it fused itself to the seal bore. This effect ruined the seal bore and made the protective sleeve effectively non-removable. 
   The problem that has not been addressed by the prior designs has been how to make a removable protective sleeve that is rotationally locked, simple to install before the through tubing operation and just as simple to remove after the through tubing operation when access to the seal bore was needed. The preferred embodiment described below provides the solution for a sleeve that goes in or out simply and is locked rotationally when in place. 
   The following U.S. patents are generally related to the use of internal seal bores and the sealing assemblies that can engage them: U.S. Pat. Nos. 1,762,211; 2,751,235; 2,754,136; 3,244,424; 4,899,816; 5,180,008 and 6,024,172. 
   Those skilled in the art will better understand the various embodiments from a description of the preferred embodiment and the drawings that appear below, with the claims defining the full scope of the invention. 
   SUMMARY OF THE INVENTION 
   A protective sleeve can be inserted through tubing and latched in a manner that resists rotation. At the conclusion of the through tubing operation that involves rotational movement, the sleeve is withdrawn on the string that previously extended through it. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exterior view of the protective sleeve in the run in position; 
       FIG. 2  is a section view through the protective sleeve in  FIG. 1 ; 
       FIG. 3  is an exterior view of the protective sleeve in the latched position; 
       FIG. 4  is a section view of  FIG. 3  shown with the internal string removed for clarity with the protective sleeve in a position where it can be removed; 
       FIG. 5  is a detailed view of the dogs in the latched and fully supported position that is otherwise shown in  FIG. 3 ; 
       FIG. 6  is a detailed view of one of the dogs; and 
       FIG. 7  is an inside view of the tubular in which the protective sleeve will be mounted showing the longitudinal grooves that can provide the rotational locking. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  shows the protective sleeve assembly  10  supported by a sub  12  that is part of the through tubing string (not shown). The protective sleeve assembly  10  has an upper member  14  that is secured to sub  12  for run in with a shear pin  16 . Member  14  is castellated at its lower end  18  by virtue of alternating fingers  20  with gaps  22  in between them. Lower member  24  has an upper end  26  that is castellated with fingers  28  separated by gaps  30 . Lower member  24  has a plurality of flexible dogs  32  that have longitudinally oriented wickers  34 , shown in  FIG. 6 , to provide resistance to rotation. These dogs  32  are preferably made integrally to lower member  24  by a pair of longitudinal cuts  36  and  38  so that dogs  32  can flex inwardly during run in and move outwardly when supported by inner sleeve  40 , as shown in  FIG. 4 . Inner sleeve  40  is secured to upper member  14  at thread  42 , as shown in  FIG. 2 . 
   In the run in sequence, the dogs  32  are unsupported as inner sleeve  40  is above them. The dogs  32  are free to be deflected inwardly as sub  12  is advanced.  FIG. 7  shows a detail of the inside of the tubular  44 . One assembly of many is shown with those skilled in the art knowing that there is one such assembly in  FIG. 7  for each dog  32 . Inclined surfaces  46  and  48  reorient and guide a respective dog  32  into a longitudinal through  50  in the tubular  44 . When the dogs  32  respectively hit bottom  52  in the tubular  44  the lower member  24  no-goes. A further set down weight results in breaking of the shear pin  16 . At that point the upper member  14  takes with it inner sleeve  40  as fingers  20  move into gaps  30  and fingers  28  enter gaps  22 . When the upper member  14  is fully moved down, it is rotationally locked to the lower member  24 . At the same time the inner sleeve  40  has moved down and become locked as C-ring  54  has come into alignment with groove  56 . The lower end  58  of inner sleeve  40  has fingers  60  that snap into a recess  62  inside of dogs  32  as shown in  FIG. 5 . At this point the sleeve assembly  10  is installed and rotationally locked. 
   For retrieval,  FIG. 2  shows a shoulder  64  on sub  12  that engages a shoulder  66  on inner sleeve  40 . When sub  12  is moved up and these shoulders engage, the inner sleeve  40  is brought up with respect to lower member  24  that is still held to the tubular  44  by dogs  32 . The upward movement of inner sleeve  40  undermines the dogs  32  as C-ring  54  comes out of groove  56 . Eventually, a shoulder  68  in the inner sleeve  40  catches a shoulder  70  on the lower member  24  to pull the lower member  24  out of the tubular  44 . Those skilled in the art will appreciate that lower member  24  can have an extension piece  72  attached at thread  74  to extend down for example into a subsurface safety valve to span the seal bores above and below a flow tube. The subsurface safety valve is not shown. Other type of equipment can be protected with the sleeve assembly  10 . 
   The rotational locking can be accomplished by the presence and orientation of the wickers  34  on the dogs  32  acting alone. Alternatively, the dogs  32  can go into longitudinal troughs  50  to obtain the rotational locking feature. As another variation, these features can be combined. The castellation is but one execution of a feature in the preferred embodiment that allows the dogs  32  to be locked in place and then rotationally locks the portion of the device that translates to achieve the locking. In this case the inner sleeve  40 , which is the piece of the assembly likely to get direct contact from an internal rotating string, is rotationally locked because of the castellation contact with the lower member  24 , which is, in turn, secured to the tubular  44  in a manner that prevents rotation. The components that are threaded together such as for example at thread  74  can have the proper thread orientation so as not to become undone upon receiving impacts from the internal rotating string when the sleeve assembly is in place. Another feature of the device is that the dogs  32  when supported with sleeve  40  are locked in that position due to the interaction of C-ring  54  in groove  56 . Should the retrieval of the sub  12  not result in release of the assembly  10 , a fishing neck  76  is provided to assist in the removal in a separate run in the hole. 
   The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made without departing from the spirit of the invention.

Technology Classification (CPC): 4