Abstract:
A tubing connection release system. The system includes, a male connector having a profile at one end thereof and receptive to a tubular at the other end thereof, a female connector receptive to a tubular at one end thereof and receptive to the male connector at the other end thereof. The system further includes, a sleeve disposed radially inwardly of the female connector, and a collet having at least one deflectable collet finger disposed radially inwardly of the sleeve. The collet is biased to a position within the female connector whereat the at least one collet finger is supported against radially outward deflection. The collet is further movable by the push-in connector against the bias to a position where the at least one collet finger is radially outwardly unsupported such that the profiled end of the male connector is movable into engagement with the at least one collet finger.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims priority to G.B. provisional application, 0515073.5, filed Jul. 22, 2005, the entire contents of which are incorporated herein by reference. 
   FIELD OF THE INVENTION 
   The present invention relates to a connector for use downhole and to a release and/or retrieval tool for releasing, and/or retrieving the connector from downhole. 
   BACKGROUND OF THE INVENTION 
   The use of connectors to join lengths of tubing in oil wells is well known. One particular use of connectors is to connect lengths of tubing together to form a straddle to seal, for example, a perforated zone that is no longer producing hydrocarbons, or a leak in a section of casing. 
   Conventional modular straddle systems where the straddle is made up of connected sections of tubing, can be difficult to remove from a well as multiple sections or modules may return to surface at the same time and be too large to be removed from the lubricator section. 
   Accordingly, tube connectors that are releasable and tools that release them and allow them to be retrieved from downhole may be desirable in the art. 
   BRIEF DESCRIPTION OF THE INVENTION 
   Disclosed herein relates to a tubing connection release system. The system comprising, a male connector having a profile at one end thereof and receptive to a tubular at one end thereof, a female connector receptive to a tubular at one end thereof and receptive to the male connector at another end thereof. The system further comprising, a sleeve disposed radially inwardly of the female connector, and a collet having at least one deflectable collet finger disposed radially inwardly of the sleeve. The collet being biased to a position within the female connector where at least one collet finger is supported against radially outward deflection. The collet further being urgable by the push-in connector against the bias to a position where at least one collet finger is radially outwardly unsupported such that the profiled end of the male connector is movable into engagement with at least one collet finger. 
   Further disclosed herein is a device that relates to a release and retrieval tool. The tool comprising, a body, a first collet selectively repositionably attached to the body such that repositioning relative to the body occurs at a first selected load related to a disengagement position of a target engagement. The tool further comprising, a second collet selectively repositionably attached to the body such that repositioning relative to the body occurs at a second selected load related to a disengagement position of a target device subsequent to the disengagement. 
   Further disclosed herein is a device that relates to a diagnostic shifting tool. The tool comprising, a mandrel having at least one recess therein. The tool further having a collet disposed at the mandrel and positionable on the mandrel to support or unsupport a deflectable finger of the collet with respect to a release arrangement. The release arrangement selectively retaining a portion of the collet relative to the mandrel pending the collet experiencing a load exceeding a load retaining capability of the release arrangement. The load retaining capability being selected to allow release at a load less than a load associated with failure of a target device. 
   Further disclosed herein is a method for diagnosing a release and retrieval problem. The method comprising, running a release and retrieval tool having a pair of load limited release mechanisms. The method further comprising, engaging a disengagement mechanism in a target device with the tool, attempting to disengage the disengagement mechanism in the target device with the tool, engaging a retrieval feature of the target device with the tool. Subsequently, pulling the tool uphole, and examining the tool release mechanisms for evidence of overload. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
       FIG. 1  is a perspective view of a section of tubing section including a female and a male connector portion according to an embodiment of the present invention; 
       FIG. 2  is a cross-sectional side view of the female connector of  FIG. 1 ; 
       FIG. 3  is a cross-sectional side view of the male connector of  FIG. 1 ; 
       FIG. 4  is a perspective view of a releasing and retrieval tool for releasing and retrieving the section of tubing string of  FIG. 1 ; 
       FIG. 5  is a cross-sectional side view of the tool of  FIG. 4 ; 
       FIG. 6  is a cross-sectional side view of the section of tubing string of  FIG. 1  prior to engagement with an adjacent section of tubing string; 
       FIG. 7  is a cross-sectional side view of the sections of tubing string of  FIG. 6  connected; 
       FIG. 8  is a cross-sectional side view of the tool of  FIG. 4  prior to entering the connected tubing strings of  FIG. 7 ; 
       FIG. 9  is a cross-sectional side view of the tool of  FIG. 8  partially inserted into the connected sections of tubing string; 
       FIG. 10  is a cross-sectional side view of the tool and the connected sections of tubing string particularly showing the tool releasing collet profile engaged with the female connector latch sleeve no-go; 
       FIG. 11  is a cross-sectional side view of the tool and the connected sections of tubing string particularly showing the tool releasing collet profile passing the female connector latch sleeve no-go; 
       FIG. 12  is a cross-sectional side view of the tool and the connected sections of tubing string particularly showing the tool releasing collet shoulder engaged with the female connector latch sleeve no-go; 
       FIG. 13  is a cross-sectional side view of the tool and the connected sections of tubing string particularly showing the tool releasing collet profile engaged with the female connector latch sleeve no-go; 
       FIG. 14  is a cross-sectional side view of the tool and the connected sections of tubing string particularly showing the tool moving towards the surface having moved the latch sleeve such that the female connector can be pulled away from the adjacent male connector. 
       FIG. 15  is a cross-sectional side view of the tool and the connected sections of tubing string particularly showing the retrieving collet engaging the tubing string male connector internal profile permitting the section of tubing string to be recovered; 
       FIG. 16  is an enlarged cut away perspective view of the latch collet passing over the male connector external profile; 
       FIG. 17  is an enlarged cut away perspective view of the latch collet secured to the male connector external profile; 
       FIG. 18  is a cross-sectional side view of the latch collet secured to the male connector external profile; 
       FIG. 19  is an enlarged cut away side view of the retrieving collet prior to engaging the male connector portion inlet section; 
       FIG. 20  is an enlarged cut away side view of the retrieving collet passing through the male connector portion inlet section; 
       FIG. 21  is an enlarged cut away perspective view of the release collet engaging the latch sleeve no-go; 
       FIG. 22  is an enlarged cut away side view of the release collet profile engaging the latch sleeve no-go; 
       FIG. 23  is an enlarged cut away perspective view of the latch sleeve shown jammed in the secured position by debris; 
       FIG. 24  is an enlarged cut away perspective view of the release collet deflecting to pass the latch sleeve no-go; and 
       FIG. 25  is an enlarged cut away perspective view of the release collet released from the latch sleeve no-go. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   A detailed description of several embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
   Referring firstly to  FIG. 1 , there is shown a section of tubing string generally indicted by reference numeral  10  including a female connector portion  12 , and a male connector portion  14 , according to a first embodiment of the present invention. The tubing string  10  also includes a length of tubing  16  and is shown located inside a cased bore  18 . 
   Referring to  FIG. 1  and to  FIG. 2 , an enlarged cross-sectional side view of the female connector of  FIG. 1 , the female connector portion comprises a housing  20 , a latch  22 , and a latch support  24 . 
   The latch  22  is a collet  26 , which includes a plurality of collet fingers  28 , each collet finger  28  defining a radially inwardly extending profile  30 . The profile  30  is adapted to engage a complementary recess defined by an adjacent male connector portion profile (not shown). Also visible are a pair of seals  21 , which engage and seal the tubing section  10  to an adjacent tubing section. 
   The latch support  24  is an axially moveable sleeve  32 , having a latch engaging surface  33  and a latch support recess  92 . 
   The male connector portion  14  can be seen in  FIG. 3 , which is an enlarged cross-sectional side view of the male connector portion  14 . The male connector portion  14  comprises a housing  34  defining a raised external profile  36  adapted to engage the collet finger profile  30  of an adjacent female connector portion (not shown). 
     FIG. 4  shows a perspective view of a releasing and retrieving tool  40 , for releasing the tubing string  10  from an adjacent tubing string, and retrieving the tubing string  10  to surface. A cross sectional side view of the releasing and retrieving tool  40  is shown in  FIG. 5 . 
   The tool  40  comprises a releasing means  42  and a retrieving means  44 . 
   The releasing means  42  is a releasing collet  46  comprising a plurality of collet fingers  48  defining an outwardly extending profile  50 . The releasing collet  46  is mounted circumferentially around a lower tool body  52 . 
   The retrieving means  44  is also a collet  54 , having fingers  56  defining a radially extending profile  58 . The retrieving collet  54  is mounted to an upper tool body  60 . 
   As can be seen from  FIG. 5 , both collets  46 , 54  are axially moveable with respect to their respective tool body  52 , 60 . The releasing collet  46  includes a shear screw  62 , which is moveable within a slot  64  defined by the lower tool body  52 . The releasing collet  46  is biased to the rest position shown in  FIG. 5  by means of a spring  66  (shown in broken outline). In this position the releasing collet finger profile  50  is prevented from flexing inwardly by an increased diameter portion  68  of the lower body  52 . When the collet  46  is located such that the shear screw  62  is at the other end of the slot  64 , the collet fingers  48  can deflect radially inwards into a reduced diameter portion  70  of the lower body  52 . 
   The retrieving collet  54  operates in a similar way, with the shear screw  72  being adapted to slide in slot  74  and the retrieving collet  54  being biased to the rest position shown in  FIG. 5  by means of spring  76  (shown in broken outline). The retrieving collet  54  is prevented from flexing inwardly in this rest position by the increased diameter section  78  of the upper body portion  60 . When the retrieving collet  54  has moved axially, such that the shear screw  72  is at the other end of the slot  74 , the collet fingers  56  can deflect inwardly towards the reduced diameter section  80  of the upper body portion  60 . 
     FIGS. 6 to 15  are a series of cutaway side views of showing a section of the tubing string  10  connecting to an adjacent section of tubing string  82  ( FIGS. 6 and 7 ) and the tubing string  10  being released from the adjacent string  82 , retrieved to surface by means of a releasing and retrieving tool  40  ( FIGS. 8 to 15 ). 
     FIG. 6  shows the tubing string  10  being moved in the direction of arrow A, that is downhole, towards the adjacent tubing string  82 . The female connector portion  12  of the string  10  engages the male connector portion  84  of the adjacent string  82 . 
   As can be seen from  FIG. 7 , the latch collet finger profile  30  passes over and engages the male connector portion external profile  86 . The interim steps of this engagement can be seen more clearly in  FIGS. 16 and 17 , which will now be described. 
     FIG. 16  shows a partially cutaway enlarged side view of the female connector portion  12  engaging with the male connector portion  84 . As the male connector portion  84  is introduced into the female connector portion  12 , the male portion leading edge  88  impacts on the latch profile  30 . This impact causes the latch collet  26  to move towards the latch spring  90 , depressing the spring  90 . 
   As the latch collet  26  moves, the latch engaging surface  33  on the latch support  26  no longer prevents the profiled end of the collet finger  28  deflecting outwardly. As the force in the spring  90  approaches the force applied by the male connector portion  14 , the latch collet  26  will deflect into the recess  92  defined by the latch support sleeve  32 . This deflection permits the collet  26  to open up sufficiently to permit the male connector profile  86  to pass the collet finger profile  30 . 
   Turning now to  FIG. 17 , once the male connector profile  86  has passed the collet finger profile  30 , the spring  90  forces the collet  26  back to the position in which the latch support sleeve  32  prevents deflection of the fingers  28 . This is shown in  FIG. 18 , an enlarged cross-sectional side view of tubing string  10  connected to an adjacent tubing string  82 . In this position, the collet finger profile  30  is secured in position by the latch support sleeve  32 , particularly by the latch engaging surface  33 , preventing the tubing strings  10 , 82  from being pulled apart. 
   Referring now to  FIG. 8 , this is the first figure in a series showing the release of the tubing string  10  from the tubing string  82  and its retrieval to surface. For this purpose, a releasing and retrieving tool  40  is introduced. 
   As the tool  40  is introduced ( FIG. 9 ), the releasing collet profile  58  passes through the male connector portion  14  unhindered as the internal diameter of the male connector portion  14  is wider than the external diameter described by the releasing collet profile  50 . 
   The retrieving collet profile  58 , however, describes a greater diameter than the diameter described by the inlet portion  94  of the male connector portion  14 .  FIGS. 19 and 20  are partially cutaway enlarged views showing the retrieving collet  54  entering the male connector portion  14 . As the tool  40  passes through the male connector  14 , the retrieving collet profile  58  impacts on the male connector inlet portion  94 . When this happens, the retrieving collet  54  is forced axially against the spring  76  permitting the retrieving collet fingers  56  to deflect into the reduced diameter region  80  of the upper housing body  60 . The axial movement of the retrieving collet  54  is guided by the shear screws  72  sliding in the slot  74 . The deflection of the collet fingers  56  causes a reduction in the diameter described by the collet finger profile  58 , permitting the retrieving collet to pass through the male connector inlet portion  94 . 
   The tool  40  then passes through the tubing string  10  to the position shown in  FIG. 10 . In this position the releasing collet profile  50  engages a no-go  96  attached to the support sleeve  32 . This engagement forces the collet latch  46  against the spring  66  permitting the collet fingers  48  and the profile  50  to deflect into the lower body reduced diameter portion  70 , permitting the releasing collet to pass by the no-go  96 . 
     FIG. 11  shows the collet fingers  48  at their maximum deflection, which occurs as the releasing collet  46  passes the no-go  96 . Once the releasing collet profile  50  has passed the no-go  96 , the spring  66  recovers the releasing collet  46  to its rest position. 
   The tool  40  continues into the female connector portion until the collet shoulder  98  impacts on the no-go  96 , as shown in  FIG. 12 . This can be seen more clearly in  FIG. 21 , a partially cutaway perspective view of the collet shoulder  98  engaging the latch sleeve no-go  96 . 
   This impact informs an operator at surface that the tool  40  has reached the extent of its travel. As the tool  40  can travel no further through the tubing string  10  only one section of string can be retrieved. This is particularly important if the lubricator section (not shown) at surface can only permit the removal of one section of tubing string  10  at a time. 
   The direction of the tool  40  can now be reversed, that is the tool  40  is now retrieved towards surface. 
   Turning now to  FIG. 13 , as the tool  40  is retrieved towards surface, the releasing collet profile  50  engages the no-go  96 . As the releasing collet is in its rest position, the shear screws  62  are already at the extreme end of their travel along slot  64 . The force applied through the tool will act on the no-go  96  and in turn on the sleeve  32 . This force pulls the sleeve  32  to the position shown in  FIG. 22 , a partially cutaway side view of the releasing collet  46  acting on the no-go  96  to move the latch support sleeve  32 . 
   As the movement of the latch support sleeve  32  continues, the no-go  96  moves towards a housing recess  100 . Once the housing recess  100  is reached, the force on the no-go  96  causes the no-go  96  to slide into this recess  100  permitting the retrieval tool  40  to move away from the female connector portion  12 . In this position, shown in  FIG. 14 , the latch support sleeve  32  no longer maintains the collet latch fingers  28 , and in particular, the latch profile  30  in contact with the male connector portion  84 . Once the retrieving collet  54  starts to pull on the tubing section  10 , the latch collet fingers  28  can deflect outwards and pass over the male connector profile  86 . 
   Referring back to  FIGS. 14 and 15 , in  FIG. 14  the female connector portion  12  has been successfully released from the adjacent male connector portion  84 , and the tool  40  is moving through the tubing string  10  to a position where the retrieving collet profile  58  can engage an internal profile  38  defined by the male connector portion  14 . As the retrieving collet shear screw  72  is at the maximum extent of its travel within slot  74 , the force applied from surface to the retrieving tool  40  will cause the tubing string  10  to lift to surface (as shown in  FIG. 15 ). 
   If, for whatever reason, the latch support sleeve  32  will not move, the tool  40  is adapted to release from the female connector portion  12  without causing damage to the connector portion  12 . This is now described with reference to  FIGS. 23 to 25 , partially cut away perspective views of the releasing collet  46  passing the latch sleeve no-go  96 . 
   Referring firstly to  FIG. 23 , debris  102  has built up behind the support sleeve  32 . This debris  102  is preventing the sleeve  32  from moving to a position in which the no-go  96  can enter the recess  100 , and permit the tool  40  to vacate the female connector portion  12 . In this situation, the pulling (or pushing) force applied to the tool  40  is insufficient to move the sleeve  32 . The force increases to a point where the shear screws  62  shear. 
   When this happens the lower body portion  52  moves up the tubing string  10  (see  FIG. 24 ). Once the lower body  52  moves with respect to the collet fingers  48 , the releasing collet fingers  48  can deflect radially inwards and pass by the no-go  96  ( FIG. 25 ). When the tool  40  is finally recovered to surface, an operator would note that the releasing collet shear screws  62  have been sheared, indicating that the problem with retrieving the tubing string  10  lies in the releasing of the female connector portion  12  from the adjacent male connector portion  84 . 
   If the tubing string  10  is stuck, for example, because the female connector  12  portion has not been released from the male connector portion  84 , or if the tubing string  10  is jammed in the case for some other reason, the shear screw  72  will shear, and the upper tool body  60  will move with respect to the retrieving collet  54  towards surface. The retrieving collet fingers  56  can then deflect towards a reduced tool body diameter  70  permitting the retrieving collet  54  to pass the internal profile  38 , and allow the retrieving tool  40  to be recovered to surface. 
   In this situation an operator can inspect the tool  40 , and diagnose why the tubing string  10  has not been recovered to surface. If the releasing collet  46  is intact, and the retrieving collet  54  is sheared, then the tubing string  10  has been released from the adjacent string  82 , but it has become stuck or jammed in the casing. If both collets  46 , 54  are sheared, then the releasing collet  46  has failed to release the female connector portion  12  from the male connector portion  84  of the adjacent string  82 . 
   Various modifications may be made to the described embodiment without departing from the scope of the invention. For example, it will be understood that the releasing and retrieving tool could engage a profile on the female connector to recover the section of tubing string to surface. 
   Those of skill in the art will recognize that the above-described embodiment of the invention provides a connector that can be separated by an internal release mechanism. 
   While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims.