Abstract:
A subterranean tool can be actuated with one or more control lines for a hydraulic release. It can further be actuated with a shear release after a lockout feature for the shear release is defeated. The shear release features a lock that limits relative movement so that a shear member can be defeated but without a release. A dog limits relative movement in a wider groove where dog movement in the groove allows a shock absorbing feature to act to cushion the release as the shear member breaks. The relative movement is reversed to let a retaining ring drop out of the way into a groove that comes into alignment with it. The relative movement is reversed again to pull a sleeve out from under gripping collets that have previously failed to release and the tool releases from that point on the same way as the control line actuated release.

Description:
FIELD OF THE INVENTION 
     The field of the invention is subterranean tools and more particularly tools that release hydraulically with a backup protected shear release that further provides a soft release to avoid damaging components in the shear release alternative. 
     BACKGROUND OF THE INVENTION 
     Frequently an upper string needs to be anchored to a packer to support tools on the string such as an electric submersible pump. Such tools block access below the packer and on some occasions need to be removed from the wellbore for maintenance. Typically the packer has an associated barrier valve that needs to be closed when the upper completion is released from the packer. To hold the upper completion to the packer generally in a polished bore receptacle an anchor or disconnect is used. There are several concerns with such applications that are run in together attached to the packer. There is the concern of an unintentional disconnection such as when setting the packer with internal pressure or when trying to get the assembly to advance to the desired location. In tools that disconnect with an applied force to break a shear pin there is also a concern that the stretch in the string at the time of release would provide a violent ricochet and damage some of the parts such as the actuator attached to the packer barrier valve. 
     Tools that release with the breaking of a shear pin or the flattening of a stack of Belleville washers are known for example in U.S. Pat. No. 6,053,262. Some tools replace collets and shear pins in a disconnect to gain full circumferential support in a locked position as in U.S. Pat. No. 7,426,964. 
     Devices have been used to reduce shock in the context of dropped tools that have a crushable nose as in U.S. Pat. No. 7,779,907 while others allow a controlled release of parts in a manner to avoid damage to the parts using a multi-dimensional pin in a bore that allows pulling to get a surface signal of landing in a casing collar before sufficient pin movement in the bore to allow a reduction of applied surface force before any release of components. This device is illustrated in US Publication 2011/0056678. U.S. Pat. No. 6,367,552 shows a travel joint that is held together until applied force meters fluid through an orifice to then permit enough relative movement to unlock the travel joint components for relative movement. 
     What is lacking in these tools is options for the release that also address in the space limitations of subterranean tools a way to control which release mode is operative at any given time and the ability to minimize damage to associated components when the release would otherwise be violent such as breaking one or more shear pins with a release force applied to a string. The present invention provides hydraulic release or actuation as the primary mode of operation. When operating in this mode the shear release mechanism can be protected from stress from forces applied to the string. Optionally the locking feature that protects the shear device can be disabled for normal operation of the tool with the packer set. If for any reason the manipulation of hydraulic pressure in the control line to the tool does not permit a release by a simple pull on the string a shear device is broken but with travel limited so that disconnection does not occur. Instead a shock absorbing member provides the needed relative movement for defeating the shear member while absorbing the shock of the release. Reversing the relative movement then releases fully two adjacent components so that collets can be undermined for a low force separation that will not harm the barrier valve actuation system that is still engaged to the anchor or disconnect as the upper sting comes out of the hole. While one application is described those skilled in the art will appreciate that other tools can benefit from the described designs in the description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is to be determined from the appended claims. 
     SUMMARY OF THE INVENTION 
     A subterranean tool can be actuated with one or more control lines for a hydraulic release. It can further be actuated with a shear release after a lockout feature for the shear release is defeated. The shear release features a lock that limits relative movement so that a shear member can be defeated but without a release. What limits the relative movement is a dog in a wider groove where dog movement in the groove allows a shock absorbing feature to act to cushion the release as the shear member breaks. The shock absorber can be a crushable ring of a soft metal. The relative movement is reversed to let a retaining ring drop out of the way into a groove that comes into alignment with it. The relative movement is reversed again to pull a sleeve out from under gripping collets that have previously failed to release and the tool releases from that point on the same way as the control line actuated release. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic view of the anchor connected to a packer with the packer in the set position; 
         FIG. 1B  is the view of  FIG. 1  showing the upper string with any attached tool coming out as the anchor is released; 
         FIG. 2  is a detailed section view of the anchor in the run in position; 
         FIG. 3A  shows applied control line pressure to the view of  FIG. 2  and before parts start moving; 
         FIG. 3B  is the view of  FIG. 3A  after the pistons have shifted left to unsupport the locking dogs; 
         FIG. 3C  is the view of  FIG. 3B  with the pistons shifted right to disable the primary piston as a result of removal of control line pressure, which fully disables the lockout for the shear ring and positions the secondary piston to allow a release on subsequent pressure applied to the control line; 
         FIG. 4A  shows the application of hydraulic pressure to unsupport the collets for a normal hydraulic release; 
         FIG. 4B  is the view of  FIG. 4A  showing a pulling force applied to get the components to release; 
         FIGS. 5A-5C  show again the movements in  FIGS. 3A-3C  but this time the collets are still supported in  FIG. 5C  and a shear release becomes necessary; 
         FIG. 6A  shows an applied force after a failure of the hydraulic release as a way of initiating the shear release; 
         FIG. 6B  shows the shear ring broken due to relative movement but with the collets still supported and the shock absorber taking the shock of the breaking of the shear ring within the limits of travel of a lock ring in a lock ring groove; 
         FIG. 6C  shows a reversal of relative movement to let the lock ring drop into a groove to free up the latch body from the release sleeve; 
         FIG. 6D  shows an applied tensile force to start the separation from the polished bore receptacle; 
         FIG. 6E  shows further movement beyond the position in  FIG. 6D  toward a separation; and 
         FIG. 7  is the view of  FIG. 6E  showing more of the tool in the same position as the tool is shown in  FIG. 6E . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1 and 2 , a packer  10  is schematically illustrated in the set position against a wellbore wall or surrounding tubular  12 . A barrier valve or formation isolation valve  14  is located below the packer  10  and a polished bore receptacle  16  is above the packer mandrel  18 . A tool such as an electric submersible pump  20  is supported by string  22 . The preferred embodiment of the present invention is an anchor  24  that is secured to the polished bore receptacle  16  and selectively released in one of the described modes below with operation of the hydraulic system shown in this view schematically as a control line  26 .  FIG. 2  shows that separation can be accomplished so that the tool  20  can come out with the string  22  while at the same time the formation isolation valve  14  is closed to isolate zone  28  as a result of the polished bore receptacle  16  being open when the tool  20  is removed. Although the invention will be described in the context of the preferred embodiment of an anchor, that is only by way of example as other tools can benefit from the described systems below and the manner that they are assembled and operated. 
     The details of the anchor assembly  24  are better seen in  FIG. 2 . Mandrel  30  has a through passage  32  and a lower end  34  with an external seal  36  against the polished bore receptacle  16 . An inner sleeve  38  supports one or more dogs  40  that extend into a groove  42  in an outer sleeve  44 . Said inner sleeve  38  and said outer sleeve  44  comprise the movable member. Mandrel  30  has an outer wall that defines an annular space  46  in which sits a collet ring  48  with a series of extending fingers capped by heads  50  that have a grip surface  52  that engages grip surface  54  at the upper end of the polished bore receptacle  16 . Ring  48  with heads  50 , having the grip surface  52 , on the end of the fingers are considered the final controlled element. For run in a support dog or dogs  56  is axially sandwiched between rings  58  and  60 . Rings  58  and  60  are mechanically connected to mandrel  30 . Ring  58  can slide with inner sleeve  38  and ring  60  is secured to outer sleeve  44 . Outer sleeve  44  is held in position at end  62  by the polished bore receptacle  16  and at end  64  by heads  50  that are held fixed to the grip surface  54  of the polished bore receptacle  16  by virtue of the underlying support collet or ring  56  that is in turn supported by inner sleeve  38 . A shear ring or some other breakable member  66  extends between mandrel  30  and outer sleeve  44 . In the  FIG. 2  position mandrel  30  cannot move up in the direction of arrow  68  because the dogs  40  are supported in groove  42  of the outer sleeve  44  by the inner sleeve  38 . Ring  70  sits in groove  72  that is axially wider than ring  70 . A shock absorber  74  is adjacent ring  70 . The purpose of ring  70  in wider groove  72  is to allow enough axial mandrel  30  movement when the dogs  40  are allowed out of groove  42  by initial sliding of inner sleeve  38  and an upward pull on the mandrel  30  in the direction of arrow  68  as will be explained more fully below. 
     An upper chamber  76  is separated from annular space  46  by a seal  78 . Primary piston  80  is preferably l-shaped and has a travel stop surface  82  and opposed seals  84  and  86 . Seal  86  rides in bore  88  and seal  84  rides on inner sleeve  38  to define a sealed sub-chamber  90  with seal  78 . A control line  92  is used to selectively pressurize and to remove pressure from sub-chamber  90 . A secondary piston  94  has seals  96  and  98  in bore  88 . Seal  98  is against the bore  88  and seal  96  is against the inner sleeve  38 . Both pistons  80  and  94  are annular pistons. A return rod  100  is held in the position shown during run in against the force of a spring  104  by a latch  102 . As will be explained below, release of the latch  102  will allow the spring  104  to push the return rod  100  against the primary piston  80  to a point where seal  86  will come out of bore  88  to effectively disable the piston  80  from moving in response to another pressure application in the control line  92 . 
     The basic components of the apparatus now having been described the normal hydraulic release feature will now be described in more detail.  FIG. 3A  shows the parts in the same run in position of  FIG. 2  and now in half section for greater clarity. Pressure is applied to control line  92  in  FIG. 3B . This makes chamber  90  volume increase as primary and secondary pistons  80  and  94  move in tandem in the direction of arrow  68 . Secondary piston  94  shoulders against the inner sleeve  38  and makes inner sleeve  38  also move in the direction of arrow  68 . Such movement of inner sleeve  38  takes inner sleeve  38  out from under the dogs  40  allowing the dogs to fall into groove  106  now made available to the dogs  40  by the movement of the inner sleeve  38 . This movement is essentially the unlocking of a lock that now frees the mandrel  30  to move relative to the outer sleeve  44  but such movement does not take place merely by adding pressure to control line  92 . Rather a shear release that comprises breaking ring  66  is enabled in  FIG. 3B  but it does not occur. As long as pressure is held in control line  92  the parts will hold the  FIG. 3B  position. Included in the  FIG. 3B  movements is the movement of the latch  102  to a position to allow the spring  104  to move the return rod  100  when pressure in line  92  is relieved from the surface. It is also worth noting that the heads  50  continue to be supported for a grip onto the polished bore receptacle  16  by virtue of the fact that the position of the collet or ring support  56  has not shifted despite the axial movement of the inner sleeve  38 . In  FIG. 3C  the pressure in the control line  92  is released and the spring  104  takes the rod  100  against surface  82  of piston  80  so that piston  80  bottoms out on stop  106  as seal  86  comes out of bore  88 . The pushing back of piston  80  takes piston  94  with it because the two are liquid locked in bore  88  and move in tandem. Optionally chamber  76  can be open to annulus pressure that can assist in the return motion of pistons  80  and  94 . Again support  56  has not moved in  FIG. 3C  and the grip to the polished bore receptacle  16  is still maintained. 
     Referring now to  FIG. 4A  the pressure is again applied to control line  92 . This time piston  80  is unaffected by this pressure as one of its seals  86  is out of bore  88 . Now pressure just drives piston  94  that again takes with it the inner sleeve  38  but this time the motion is not curtailed by stop surface  82  now held back by rod  100  using spring  104 . Now piston  94  takes inner sleeve  38  in the direction of arrow  68  a distance great enough to allow the collets or ring support  56  to fall against the mandrel  30  and remove the supports for the heads  50  so that an upward pull on the mandrel  30  in the direction of arrow  68  as shown by  FIG. 4B  will allow the heads  50  to come away from grip surface  54  and the mandrel  30  will now exit the polished bore receptacle  16 . 
       FIGS. 5A-5C  are essentially the same as  FIGS. 3A-3C  except that now when pressure is applied to control line  92  for a second time the piston  94  fails to move the inner sleeve  38  to the point where the support  56  is undermined by the sliding of inner sleeve  38  such as happened in  FIG. 4A . This can happen for example if one or both of the seals  96  or  98  on piston  94  fail. As a result a mere pulling on the mandrel  30  in the direction of arrow will not work as the heads  50  continue to be firmly held against grip surface  54  of the polished bore receptacle  16 . When this happens, the release with hydraulic pressure into control line  92  is inoperative and the backup mode of release with a tension force on mandrel  30  has to be deployed. 
     Referring to  FIG. 6A  ring  70  is in groove  72  that is shown as axially longer than ring  70 . At this time the dogs  40  have dropped out of groove  42  due to earlier sliding action of inner sleeve  38 . The shear ring  66  is intact. Because ring  70  is narrower than groove  72  a pull on the mandrel  30  with heads  50  secured to the polished bore receptacle  16  will result in the breaking of the shear ring  66  as ring  70  moves from one side of groove  72  to the other. The placement of the shock absorber  62  is such that the mandrel  30  to keep moving in direction of arrow  106  has to operate the shock absorber. In essence the mandrel  30  continues to be retained in the polished bore receptacle  16  after ring  66  is sheared and as the shock absorber  62  is operating. The shock absorber  62  can be in the form of a soft ring preferably metallic that is crushed with the relative movement of the mandrel  30  with respect to the polished bore receptacle  16 . The shock absorber  62  can be a stack of Belleville washers, a chamber forcing fluid out through an orifice, some other kind of spring, for example and not by way of limitation. The point is that the initial mandrel  30  movement that broke the shear ring  66  and activated the shock absorber  62  will not as yet release mandrel  30  from receptacle  16  because the heads  50  are still supported by support ring or collet  56 , but it will allow the released force from the breaking of the shear ring  66  to be dissipated by the shock absorber  62  so that there is no slingshot effect from the breaking of the shear ring  66 . Note that support  56  is still under the heads  50  in  FIG. 6B . 
     When the movement of the mandrel  30  is reversed to the direction of arrow  108  as in  FIG. 6C  the lock ring  70  can fall out of groove  72  and fall into groove  110  that presents itself in alignment due to the setting down weight on mandrel  30  which moved mandrel  30  in the direction of arrow  108  until travel stop  113  is engaged by mandrel  30 . With ring  70  now in groove  110  the mandrel  30  can be picked up again in the direction of arrow  106 . Note that at this time the ring  60  is not retained by outer sleeve  40  because as shown in  FIG. 6C  groove  42  is over the heads  112 . By friction between the parts the movement of the mandrel  30  and with it inner sleeve  38  will take with it support  56  and rings  58  and  60  so that support  56  is out from under heads  50  by the time the outer sleeve  40  shoulders out at end  62  against the polished bore receptacle  16 . From that point further mandrel  30  movement causes outer sleeve  40  to bump heads  50  and deflect them inwardly now that support  56  has been axially displaced. This is shown in  FIG. 6E  in close up and the whole assembly in the  FIG. 6E  position is shown again in  FIG. 7 . 
     Those skilled in the art will appreciate that what has been described is a tool with dual modes of operation. The first or preferred mode involves hydraulic system actuation. The hydraulic system sequentially moves an inner sleeve  38  in the same direction to initially unlock a lock by letting dogs  42  drop so as to enable a shear release without actually shearing the ring  66 . This sequential movement is accomplished with dual pistons that move together to a travel stop to let the dogs  42  drop and then in another pressure cycle in the hydraulic system which has the effect of disabling the primary piston uses the secondary piston to move the sleeve  38  and even greater distance in the same direction to allow support collet or ring  56  to drop to the mandrel  30  so that a pull on the mandrel  30  results in a flexing of heads  50  and a separation from the polished bore receptacle  16 . 
     Dogs  42  are a lock to prevent loading on shear ring  66  during run in and setting of the packer  10 . The shear ring  66  can be used for a backup release in the event the hydraulic system cannot get the support  56  away from the heads  50  for a release from receptacle  16 . Here there is available relative movement between the mandrel  30  and the outer sleeve  40  into which the shear ring  66  extends to allow the ring  66  to break but to prevent the sudden release from the breaking of ring  66  to create a slingshot effect that can for example damage an actuator (not shown) that is connected from mandrel  30  to the barrier valve  14 . Movement of the mandrel in a first direction that breaks the shear ring  66  and actuates the shock absorber  74  does not remove support  56  from heads  50  so that the tool stays attached to the receptacle  16 . Instead the outer sleeve  40  that retains the ring  70  makes the shock absorber  74  actuate until all movement stops. The mandrel  30  has to be moved in the opposite direction to drop the ring  70  out of groove  72  and into mandrel  30  groove  110  so that the mandrel  30  can move up and reposition support  56  away from heads  50  to release from receptacle  16 . Further raising of the mandrel  30  shoulders the outer sleeve  40  and uses sleeve  40  to deflect heads  50  inwardly so that the mandrel  30  will come clear of the receptacle  16 . 
     While the invention is described in the form of an anchor with two modes of release the invention is applicable to other downhole tools that operate from a first to a second position and get there in more than one way such as hydraulically and mechanically using a shear release but avoiding the slingshot effect that can damage other parts. The locking feature is enabled for operation and can be defeated to enable a shear release without actually shear releasing. If the hydraulic system fails to release and the locking feature has been earlier disabled then a sequence of opposed mandrel  30  movements will actuate the shear ring breaking and the shock absorber actuating while the tool is still in its initial position. After then setting down weight and picking up there will be a release or a movement of the tool to the second position. 
     The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below: