Abstract:
An actuation tool uses a lock that when released allows a moving magnet to move into position to repel another magnet. The repelling force on the second magnet moves it away from a locking position on a stored potential energy system where the release of the potential energy creates kinetic energy to drive an actuation assembly to set the tool. In a preferred application the tool can be a liner hanger. The release device can be a selectively energized electromagnet or a solenoid that shifts at least one magnet into alignment with at least one second magnet so as to defeat the second magnet from effectively storing the potential energy that can set the tool when the lock is defeated.

Description:
FIELD OF THE INVENTION 
     The field of the invention is actuation devices for subterranean tools and more particularly devices that enable selective remote actuation while avoiding wall openings and their associated seals that can present potential leak paths. The device will allow actuation of equipment without a need to have any plug in the tubing against which pressure has to be applied. 
     BACKGROUND OF THE INVENTION 
     Pressure actuated assemblies that are designed to selectively actuate a subterranean tool typically involves a ball seat and a ball that is dropped or pumped to the ball seat and landed. Once the ball is landed internal pressure is built up through a wall opening to a piston housing surrounding the main bore so that a tool can be actuated. Typically a piston receives the internal pressure through a wall port and has an opposite end referenced to annulus pressure. Raising the tubing pressure moves the piston which actuates the tool. In one example of a liner hanger, the piston can move slips and a sealing element to support a liner from a surrounding casing. 
     There can be issues with such a design. The tool can be in a long horizontal run so that it may take the ball a long time to get to the seat without having to be pumped. In a horizontal run the ball may not locate on the seat even with a flowing stream urging the ball to the seat. Wall openings to piston housings can also present potential leak paths if seals deteriorate or fail. 
     Accordingly, an actuation system is needed that can be selectively operated from a remote location to operate a tool at the desired location. In the preferred embodiment an actuation system is described that locks in potential energy with a lock that is disabled to release the potential energy to set the tool. In a preferred application a liner hanger slip system and seal can be set with the device. The lock is defeated with physical movement that is induced with an applied field or with an electromechanical device to name a few preferred options. In one embodiment the field is magnetic and the lock release is accomplished with a repelling response to a magnet that serves at least in part as a locking key and whose movement results in a release of the potential energy force. Those skilled in the art will better appreciate aspects of the preferred embodiments of the invention from a review of the description of the preferred embodiment and the associated FIGS. while recognizing that the full scope of the invention is to be found in the appended claims. 
     U.S. Pat. No. 7,703,532 illustrates moving a magnet in position to hold open a flapper in a safety valve in the open position and to reduce its tendency to chatter in the open position. US Publication 2009/0032238 illustrates a magnet used to assist the movement of a flapper in a safety valve to go to an open position by adding to the gravity force of the flapper weight that tends to move it to the open position. Another magnet can be used to urge the flapper to the closed position. U.S. Pat. No. 7,828,066 transmits power through a magnetic shaft coupling. U.S. Pat. No. 3,264,994 shows the use of a magnet on a dart that is pumped past a tool to use the field to trigger tool actuation. US Publication 2010/0126716 illustrates a hard wired system for initiating tool actuation using a magnetic field. Other patents of interest with regard to the present invention are: U.S. Pat. Nos. RE 30,988; 7,703,532; 7,669,663; 7,562,712; 7,604,061; 7,626,393 and 7,413,028. 
     SUMMARY OF THE INVENTION 
     An actuation tool uses a lock that when released allows a moving magnet to move into position to repel another magnet. Alternatively a magnetic field can be triggered in a stationary magnet such as one delivered on wireline, for example, to accomplish tool actuation. The repelling force on the second magnet moves it away from a locking position on a stored potential energy system where the release of the potential energy creates kinetic energy to drive an actuation assembly to set the tool. In a preferred application the tool can be a liner hanger. The release device can be a selectively energized electromagnet or a solenoid that shifts at least one magnet into alignment with at least one second magnet so as to defeat the second magnet from effectively storing the potential energy that can set the tool when the lock is defeated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the trigger mechanism for the lock shown in the run in position and in perspective; 
         FIG. 2  is a side view of  FIG. 1  showing the retainer for the snap ring retracted by a solenoid; 
         FIG. 3  is an alternative view of the  FIG. 2  position showing the snap ring in perspective and a portion of the snap ring that extends into a circular groove to allow the snap ring to function as a travel stop; 
         FIG. 4  is a perspective view of the  FIG. 3  position just before the springs push the tandem rings to reposition the magnets in those rings; 
         FIG. 5  is a section view of a liner hanger in the run in position showing the tandem rings holding locking segments in a locked position to prevent the slips from setting; 
         FIG. 6  is the view of  FIG. 5  showing the tandem rings shifted and the locking segments repelled so that the setting spring for the slips can move the slips; 
         FIG. 7  is the view of  FIG. 6  with the slips fully activated for gripping a surrounding tubular; 
         FIG. 8  is a perspective view of a run in position for an alternative mechanism to the  FIG. 1  embodiment that actuates with an applied magnetic field; 
         FIG. 9  is the view of  FIG. 8  in the set position; 
         FIG. 10  is a perspective view for run in of a liner hanger using the mechanism of  FIG. 8 ; 
         FIG. 11  is the view of  FIG. 10  in the set position; 
         FIG. 12  is a section view of an alternative embodiment that uses a running tool to unlock the tool using an electro-magnetic field to repel the locking magnet; 
         FIG. 13  is a detailed view of a locking segment that is repelled to shear a pin with the field presented from the running tool of  FIG. 12 ; 
         FIG. 14  is an alternative embodiment of the locking segment of  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIGS. 1-4  are best understood in conjunction with  FIGS. 5-7 .  FIGS. 5-7  illustrate an example of an application of the actuation system in the form of a liner hanger  10  that has, in one embodiment, a ring of segments  12  that axially translate with respect to each other to increase in diameter as better seen in  FIGS. 10 and 11 . The drawings are schematic and are intended to illustrate that the slips  12  in whatever way they are assembled are axially translated in tandem or relative to each other depending on the design by the force of spring  14  acting on setting sleeve  16  to push it in the direction of arrow  18 . One or more lock segments  20  are initially disposed in matching grooves  22  to prevent motion in the direction of arrow  18  by the setting sleeve  16 . Lower magnet ring  24  and upper magnet ring  26  are retained by snap ring  28  against shoulder  30  in a position where magnets  32  attract the lock segments  20  such that segments  20  are partly into groove  22  and partly into a recess  34  in the housing  36 . Instead of using magnet ring  24  a retainer that is overcome when ring  26  moves into position can be used as an alternative arrangement to retain the initial locked position. Snap ring  28  is a primary lock while segments  20  are considered the secondary lock that is actuated as a result of release of the primary lock or snap ring  28  in the preferred embodiment. Setting Sleeve  16  contains T-slots into which the segment ring  12  interlocks. Spring  14  cannot move the sleeve  16  as long as the lock segments  20  straddle grooves  22  and recesses  34 . The attraction from magnets  32  acting on lock segments  20  retains the segments  20  in the  FIG. 5  position where the grooves  22  and the recesses  34  are straddled to hold the springs  14  in the compressed position. 
     Actuation involves a release of the snap ring  28  that in turn allows the springs  40  to axially move rings  24  and  26  so that magnets  42  now align with segments  20 . Alternatively the magnets  32  and  42  can be on a single ring that can rotate instead of translating to change the polarity of the magnet facing the segments  20 . The magnets  42  have an opposite pole facing the segments  20  such that the segments  20  are now radially outwardly repelled to move out of recess  34  and fully into groove  22 . The sleeve  16  is now free to move in the direction of arrow  18  so that the slips  12  can move out radially to engage a surrounding tubular either by riding up a taper or as shown in  FIGS. 10 and 11  by relative axial movement of tapered segments that have wickers  44  as shown in  FIGS. 5-7 , for example. 
       FIGS. 1-4  show in more detail how the snap ring  28  is released. Snap ring  28  has shaped ends  46  and  48  that are retained by similarly shaped grooves in block  50 . Block  50  is selectively actuated from a surface location to move in the direction of arrow  52  by a solenoid valve assembly  54  that has an axially movable shaft  56  that moves in the direction of arrow  52  when power that is schematically represented by dashed line  58  is supplied to coil in the assembly  54 .  FIG. 2  shows the block  50  retracted in the direction of arrow  52  and the ends  46  and  48  no longer retained by block  50 . The stored potential energy in the ring  28  allows it to snap out of its associated groove  60  best seen in  FIG. 3  as the ends  46  and  48  move respectively in the direction of arrows  62  and  64 . At this point the springs  40  are able to push the rings  24  and  26  in tandem so that the segments  20  can then be radially outwardly repelled to allow the force stored in the spring  14  to move the sleeve  16  and cause the wickers  44  to bite into a surrounding tubular that is not shown.  FIG. 4  shows the components just in the instant before the springs  40  move the rings and  FIG. 7  is a section view after that movement has happened showing the wickers  44  in a set position against the surrounding tubular. 
       FIGS. 8 and 9  show another way to release the snap ring  28 ′ by movement of the block  50 ′. In this embodiment a surface controlled power source shown schematically as dashed line  66  selectively energized an electromagnet  68  that when energized repels the permanent magnet  70  to displace the block  50 ′ to the  FIG. 11  position. As before when the snap ring  28  has ends  46  and  48  exposed, the rings  24  and  26  are able to move in tandem under the force of spring  40  and the setting proceeds as previously described. 
       FIGS. 12-14  use a running tool  100  that has an electro-magnet  102  that is oriented as such that upon activation from a power source will provide an opposite pole at the outward facing surface from that of the inward facing surface of the magnet  104  to drive segment  104  radially outwardly into recess  106  so as to allow the spring  108  to push against stop  110  to allow slips  112  to climb ramp  114  to allow wickers  116  to bite the surrounding tubular. Set screw  118  holds the segment  104  to the housing  122  for run in via threads  120 . With electro-magnet  102  activated, the repelling force is sufficient to shear out the shear plate  124  to get the segments  104  fully into the recess  106 . In  FIG. 13  a plate  124  has the screw  118  extending through it and secured to housing  122  by threads  120 . In  FIG. 14  the screw  118 ′ integrates what is the plate  124  of  FIG. 13  as part of the screw head again to secure the segment  104  at thread  120 ′. 
     Those skilled in the art will now appreciate that what is disclosed is a surface controlled system that can release a stored potential energy force to set a tool where dropping objects on seats and pressuring up through wall openings that present leak paths are not an issue. Instead a primary device such as a solenoid or an electromagnet to illustrate some examples is triggered to then allow movement of magnetic members to release a key to then liberate the stored potential energy force to create kinetic energy to set a tool. 
     While a liner hanger is used in the illustrations above, other types of well tools are also contemplated. Rings  24  and  26  while shown as two discrete rings with magnet inserts  32  and  42  that are in each ring with their polarity on the outward side being different, could also be a single ring or ring segments. The entirety of the rings  24  and  26  could be magnetic rings or segments. The lock segments  20  can be magnets themselves or they can simply be constructed of a magnetic material and can have a variety of shapes that are compatible with movement of segments  20  in recesses  34  or grooves  22 . The lock segments may be a sub assembly of two components—one component will be of a mechanically strong material to ensure that the locking device can hold the stored load of springs  14  and form the shape of a cap to surround the magnetic material. The second part will be the magnetic component which will act as previously described to force the cap out of recess  34  and allow the tool to set without requiring mechanical properties from the magnetic component when being run in hole. While a coil spring  40  is illustrated the movement of the rings  24  and  26  can be accomplished with equivalent devices that store potential energy such as a volume of compressed gas or a stack of Belleville washers as some examples. While the embodiments show removing support for a snap ring  28  other alternatives that allow movement of the rings  24  and  26  can be used such as a shear ring that is snapped by a driving mechanism that gets the same motion accomplished as assembly  54 . Using a member that fails in shear will require more applied force than the illustrated embodiments that translate a block and expose ends  46  and  48  of a snap ring  28 . The attracting magnet  32  in the running tool may be removed and as such the locking segments  20  may be retained in recess  34  by another means—such as an overlaying leaf spring—until the repelling force is applied. The repelling force will always be strong enough to repel the locking segments  20  as well as overcoming any forces that are present in order to hold the locking segment  20  in place. 
     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.