Patent Abstract:
A tool for shifting a sleeve into at least one intermediate position between stops has a shifting key that only can move the sleeve a finite amount before it is forced out of contact with the sleeve. An overpull key is released for engagement with the sleeve before the shifting key is forced out. The overpull key resists movement until a noticeable predetermined force is applied at which point the overpull key is freed from the sliding sleeve for a normal release. If any key fails to release, an emergency release is provided that independently displaces the key so that the tool can be removed. The tool can be operated in either an uphole or a downhole direction to shift the sleeve depending on the orientation of the keys. Embodiments using a single key type are contemplated.

Full Description:
FIELD OF THE INVENTION 
   The field of the invention is tools and methods for shifting a sleeve into at least one position between travel end points and incorporating a signal to the surface that such a position has been reached as well as an emergency release feature for the tool. 
   BACKGROUND OF THE INVENTION 
   Sliding sleeves are used as downhole valves. They are frequently disposed in a recess in a tubular that defines opposed travel stops that coincide with two positions for the valve. The sleeve typically has a recess at opposed ends so that a known shifting tool can grab it and move the sleeve between stops. The surrounding tubular can have a port and the sleeve can have a second port. When the sleeve is against one stop the port in the tubular can be obstructed. When the sleeve is at the opposite stop, the sleeve port aligns with the tubular port for the open position. 
   Recently, designs have developed that require a valve member like a sleeve to be in more than two positions defined by its travel stops. In one such application a tubular port needs to be closed in one position, fully open in another and in a third position for alignment of a filter media with the port. In the open position a surrounding formation can be fractured with minimal flow resistance at the wide open port. In the third position, the formation fluids can be produced through the same tubing port with a sand control material in the flow path. In one such design, the sliding sleeve has two ports with one port containing the screen material. A design of this type is shown in PCT/US2005/011869. The problem arises in how the surface personnel can know when the sleeve has obtained an interim position between its travel stops. 
   One way this has been addressed in the past is to mount the sleeve on a j-slot and move it mechanically or hydraulically through the pattern in the j-slot to define any number of desired positions. This design adds complexity and cost in that in the hydraulic version a ball has to catch on a seat and pressure is cycled a given number of times to get the right position. After that the ball and seat need to get blown out so other procedures further downhole can take place. The drift diameter through the tool is reduced to make room for the pin in slot arrangement. 
   Another way to do this is using a control line to move a piston that is linked to the sleeve. A finite amount of hydraulic fluid is pumped that corresponds to a given displacement of the piston. However this method has uncertainties relating to the amount of fluid pumped being a small quantity through a long control line which can be subject to thermal effects or even a compressible gas bubble that can through off the amount of the intended movement. Additionally, the drag force of seals or the momentum of the hydraulic piston can also result in a different amount of movement than intended. 
   The present invention provides a tool and a method for shifting a sleeve to an interim position or positions between travel stops and giving feedback to the surface that the required amount of movement has taken place. In the event of a failure to release an emergency release option is available. The tool resets after a normal release and can be re-engaged if desired. The tool is operable in either direction depending on how its component parts are oriented. These and other details of the present invention will be more readily understood by those skilled in the art from a review of the description of the preferred embodiment and the associated drawings that appear below with the understanding that the appended claims represent the full scope of the invention. 
   SUMMARY OF THE INVENTION 
   A tool for shifting a sleeve into at least one intermediate position between stops has a shifting key that only can move the sleeve a finite amount before it is forced out of contact with the sleeve. An overpull key is released for engagement with the sleeve before the shifting key is forced out. The overpull key resists movement until a noticeable predetermined force is applied at which point the overpull key is freed from the sliding sleeve for a normal release. If any key fails to release, an emergency release is provided that independently displaces the key so that the tool can be removed. The tool can be operated in either an uphole or a downhole direction to shift the sleeve depending on the orientation of the keys. Embodiments using a single key type are contemplated. 

   
     DETAILED DESCRIPTION OF THE DRAWINGS 
       FIGS. 1   a - 1   d  represent the run in position with the shifting key secured in the sleeve; 
       FIG. 2  is the view along lines  2 - 2  of  FIG. 1   c;    
       FIG. 3  is the view of  FIG. 1   c  but rotated 45° to show the overpull key; 
       FIG. 4  is the view of  FIG. 1   c  with the shifting key engaged for moving the sleeve; 
       FIG. 5  is the view of  FIG. 4  rotated 45° to show the overpull key connected to the sleeve; 
       FIG. 6  is the view of  FIG. 4  with the sleeve shifted so that the shifting key is forced out of the sliding sleeve; 
       FIG. 7  is the view of  FIG. 6  to show the overpull key still registered with the sleeve; 
       FIG. 8  is the view of  FIG. 6  showing that the shifting key can&#39;t reenter the sleeve after overpulling with the overpull key; 
       FIG. 9  is the view of  FIG. 8  rotated 45° showing the overpull keys retracted from the sleeve; 
       FIG. 10  is the view of  FIG. 1   c  showing the emergency release of the shifting key; and 
       FIG. 11  is the view of  FIG. 10  rotated 45°. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   A portion of a tubular string  13  starts in  FIG. 1   b  and terminates at  15  in  FIG. 1   d . Those skilled in the art will recognize that string  13  shown in  FIG. 1   b  can go from the well surface to further down in the well below  15  but only the portion of interest in understanding the invention is illustrated. That portion has one or more ports  17  which are straddled by seals  19  and  21 . A sleeve  23  has a lower end  25  against shoulder  27  inside string  13  as shown in  FIG. 1   d . A fishing neck  29  is close to lower end  25  to allow a shifting tool to latch there to move the sleeve  23  in a downhole direction or to the right when sleeve  23  is positioned off the stop or shoulder  27 . Sleeve  23  has an upper end  29  and an adjacent fishing neck  31  where keys  36  and  50  can selectively engage as will be described below. Sleeve  23  has an array of ports  33  that are wide open and can be aligned with ports  17  for the wide open position of the ports  17 . In  FIG. 1   c  the ports  17  are closed because the sleeve  23  has a blank part straddling the seals  19  and  21 . There is a second array of ports  35  that are also capable of being aligned with ports  17 . Ports  35  have a sand control medium  37  in them. When ports  35  line up with ports  17 , well fluids can be produced through the string  13  to the surface with effective sand control. Those skilled in the art will appreciate that the preferred embodiment uses a specific tool to illustrate a situation where the sleeve needs to go into more than two positions and one of those positions corresponds to the sleeve  23  not being against the shoulder  27  or the opposite shoulder  39 . 
   To hold the sleeve  23  in the run in position of  FIG. 1   c  there is a tab  41  that extends into a groove  43  in string  13 . Further uphole, another groove  45  is positioned to catch the tab  41  to hold ports  35  of sleeve  23  aligned with ports  17  of string  13 , as will be explained below. 
   Referring now to the shifting tool that is lowered into sleeve  23 , inner mandrel  10  starts in  FIG. 1   a  and ends at  11  in  FIG. 1   d . Secured to mandrel  10  at thread  47  is bottom sub  48  which covers a pin  46  designed to keep threaded connection  47  from coming undone. Release sleeve  44  is secured at thread  47 . Sleeve  44  spans over key retainer  40  creating a chamber  49  in which spring  42  is located. The downhole end of spring  42  bears on shoulder  51  of release sleeve  44  while the uphole end of spring  42  bears on end  53  of key retainer  40 . Key retainer  40  has multiple openings  55  shown in  FIGS. 1   c ,  2  and  3  and which are circumferentially offset from adjacent such opening by preferably 45°. Extending through openings  55  in an alternating pattern shown in  FIG. 2  are the shifting keys  36  and the overpull keys  50 . A spring  38  biases each shifting key  36  radially out through opening  55  and another spring  52  biases each overpull key  50  through its respective window  55 . Near the downhole end of the shifting keys  36  is a taper  57  and near the downhole end of the overpull keys  50  is a taper  59 . In both instances these tapers allow the keys  36  and  50  to be pushed down against their respective springs and snap out for engagement into fishing neck  31  of sleeve  23  as will be explained below. As shown in  FIG. 1   c  simply lowering the mandrel  10  into the string  13  will make the shifting keys  36  retract and snap out into a gripping relation with the sleeve  23 . The overpull keys are initially held radially retracted by retainer sleeve  34  as shown if  FIG. 3 . This sleeve  34  is irregularly shaped so it doesn&#39;t overlay shifting keys  36  for run ( FIG. 1   c ) in but it does overlay overpull keys  50  for run in ( FIG. 3 ). Sleeve  34  lays on sleeve  32  and is held in place by also abutting key retainer  40  and outer sleeve  14  held at thread  61 . Inner sleeve  32  is held to key retainer  40  at thread  63 . An upper end tab  65  on inner sleeve  32  abuts tab  67  of sleeve  30  that overlays sleeve  32 . Mandrel  10  has a tab  69  against which tab  67  is abutted. Tab  69  supports ring  28  on which rests a collapsing split sleeve  26 . Sleeve  26  has a series of grooves  71  in which rest a series of projections  73  of sleeve assembly  24 , which may be in one or more pieces. 
   Mandrel  10  has threaded to it sleeve  20  and that connection is secured by pin  22 . Spacer  18  rests on sleeve  20  and spring  16  is on spacer  18 . A top sub  12  is secured to outer sleeve  14  and retains the spring  16 . Outer sleeve  14  has a shoulder  75  in  FIG. 1   b  against which sleeve assembly  24  can abut when not locked into its position in  FIG. 1   b  by the collapsing split sleeve  26  that is shown abutting sleeve  20  that is secured to mandrel  10 . 
   The components having been described, the operation of the tool will now be explained. The mandrel  10  is lowered to a shifting sleeve  23  in the string  13 . Those skilled in the art will appreciate that more than one sleeve  23  can be shifted in a given trip into the well as one of the features of the invention is that the tool resets after a sleeve shift so that it can be latched to other sleeves. While moving a sleeve  13  to an intermediate position between travel stops  25  and  39  is illustrated, the invention is applicable to moving other types of downhole equipment to one or more intermediate positions between fixed stops. Lowering the mandrel  10  allows the leading taper  57  to engage sleeve  23  so as to compress spring  38  to retract shifting keys  36  to allow them to pass into sleeve  23  and snap out into fishing neck  31 , as shown in  FIG. 1   c . At this time the overpull keys  50  are held radially retracted by sleeve  34  as shown in  FIG. 3 . 
   A pull on mandrel  10  with shifting keys  36  engaged brings up sleeve  44  close to shifting keys  36 , as shown in  FIG. 4 , while compressing spring  42 . In the  FIG. 4  position, sleeve  44  does not yet push on tapered surface  57 . At the same time, the pulling up of the mandrel  10  retracts sleeve  34  from overpull keys  50  to allow their springs  52  to push them out into fishing neck  31 , as shown in  FIG. 5 . This happens because picking up mandrel  10  lifts tab  67  against ring  28  which pushes up connected rings  24  and  26  that in turn pick up outer sleeve  14  to which sleeve  34  is attached. This upward movement of mandrel  10  can continue until sleeve  34  shoulders against surface  77  of sleeve  32  as shown in  FIG. 5 . At that time the overpull keys  50  are also engaged in fishing neck  31  as are the shifting keys. 
   Further pulling on mandrel  10  will now bring up key retainer  40  and with it keys  36  and  50  now both pulling uphole on sleeve  23 . Tab  41  will jump out of groove  43  as the sleeve  23  begins to move. After a predetermined movement the tapered uphole end  79  of shifting keys  36  will strike travel stop  39  to force the shifting keys  36  out of fishing neck  31  so that they let go of sleeve  23  and compress springs  38 , as shown in  FIG. 6 . In the  FIG. 6  position of the sliding sleeve  23  the keys  36  cannot get another grip on sleeve  23  at fishing neck  31 . At the same time in  FIG. 7  the overpull keys  50  are still engaged to sleeve  23  at fishing neck  31 . The overpull keys have an uphole shoulder  80  that no-goes against shoulder  39  on string  13  as shown in  FIG. 7 . An overpull force can now be applied as a surface signal. Note that tab  41  is now in groove  81  to hold sleeve  23  in the position where ports  35  and  17  are lined up and to keep it from inadvertently moving if bumped by other tools going into the well at a later time after the shifting tool is removed. 
   When the overpulling is done, the mandrel  10  is set down and as shown in  FIG. 8 , the shifting keys  36  cannot go into fishing neck  31 . Setting down weight also allows spring  42  to expand to bring down sleeve  34  back over the overpull keys  50  to hold them radially retracted so as to prevent them from getting a grip on fishing neck  31 . At this point an upward pull on mandrel  10  releases the tool and confirms that sleeve  23  shifted the requisite distance to get ports  35  with screens  37  in them into alignment with ports  17  in the string  13 . Other sleeves in the wellbore can now be shifted in the same manner in a single trip as the tool is now back to its run in position. 
   If for any reason keys  36  or keys  50  fail to release in the manner described above, the emergency release provisions in the tool allow for its removal. With keys  36  or  50  not releasing, further pulling on mandrel  10  puts an increasing compressive force on split sleeve  26  that ultimately forces it radially inwardly and away from sleeve  26  so that the projections  73  are no longer registered with recesses  71 . After that the mandrel  10  can come up against spring  16  taking up with it sleeve  44  that will ride up ramps  57  and  59  of the keys and push them all radially inwardly and out of registry with fishing neck  31 . At that point mandrel  10  is released and the tool can be removed from the string  13 . It should be noted that once the release occurs springs  42  and  16  relax again to put the tool into the run in position. Projections  73  register again with grooves  71  and the emergency release feature resets as well.  FIGS. 10 and 11  show the sleeve  44  moved up to cover the keys  36  and  50  so that the tool can be removed. The tool can be repositioned to operate another sleeve or taken out of the hole to be examined for any malfunction. 
   Those skilled in the art will appreciate that the present invention has the capability of shifting multiple sleeves or other tools in the same trip where each tool needs to be shifted a finite distance not defined by a downhole fixed travel stop. The tool is capable of giving a surface signal to indicate that the desired shifting has happened. As a confirmation, the shifting keys will not re-engage a given sleeve after it has been shifted to an intermediate position or positions between fixed travel stops. An emergency release is available and it resets after it operates. The keys go back to the run in position after a normal shift and release or after an emergency release. The keys can be oriented in an opposite direction and the tool will function to shift with a downhole force rather than an uphole pull as described. While a handoff between shifting keys and overpull keys has been described, a modification that allows the shifting keys to also serve as overpull keys is contemplated with the shifting keys releasing grip of the sleeve  23  as described above and then getting a second grip in the string  13  that does not release until a predetermined force is applied. This can involve catching a recess in string  13  where an elevated force is needed to release from it. Alternatively, more than 1 repositioning of a given sleeve is possible as well as finding multiple positions between stops moving the sleeve in either direction

Technology Classification (CPC): 4