Abstract:
A subterranean tool can drop multiple objects to landing locations in a tubular string. The tool can keep at least one ball out of the fluid stream until ready for release. A dart or wiper plug can be kept in the fluid stream with an open bypass until axial mandrel movement allows release of the plug or dart. The tool is rotationally locked at a lower location for run in and then can rotationally lock at an upper location upon release of the dart or ball. Axial movement that releases the dart can continue until the ball aligns with a decreasing depth groove so that relative part rotation cams the ball against a leaf spring detent and into the mandrel flow path.

Description:
FIELD OF THE INVENTION 
     The field of the invention is subterranean tools that can drop multiple objects in a desired sequence from a location near the intended object landing location or locations. 
     BACKGROUND OF THE INVENTION 
     Devices that drop balls and darts are used in a variety of applications. For example in cementing the darts are used to wipe a liner clear of cement while dropped balls on seats can be used for allowing building pressure to set tools such as liner hangers/seals that are frequently used in conjunction with equipment for running or setting a liner in existing casing. These devices can be surface mounted on cementing heads for manual or automatic operation by rig personnel or they can be located remotely from a surface location and remotely operated from the surface by fluid flow patterns or remotely actuated detents that can release a potential energy force to launch a ball. 
     U.S. Pat. No. 4,452,322 shows in  FIG. 2  a split view of a ball retained by a sliding sleeve with a flow passage through it. Fluid flow patterns with a j-slot overcome a resisting spring force and ultimately shifts the sleeve to align a port in the sleeve with a ball for gravity release of the ball. U.S. Pat. No. 7,100,700 uses high flow rates to create axial movement to release a ball at a subterranean location that is stored out of the fluid stream until released. Various surface mounted manually operated ball droppers are illustrated in U.S. Pat. No. 6,776,228 where a fork-shaped device straddles a ball and with rotation turns the ball into the flowpath. In U.S. Pat. No. 7,802,620 a handle is turned 180 degrees to cam a ball through an outlet as shown in  FIG. 2 . Finally, U.S. Pat. No. 4,577,614 shows in  FIG. 2  a remotely released detent that allows the potential energy of a spring to push balls out over the bias of a retaining leaf spring. 
     U.S. Pat. No. 7,299,880 shows a bypass that stays open to allow running of casing without surging the well where the bypass can be closed in the event of a well pressure event. 
     Some completion assemblies require torque transmitting capabilities and in some applications the ability to drop a ball on a seat if an earlier dropped dart fails to seat so a tool can be set. The present invention combines some of these capabilities by allowing release of a wiper plug with a pickup force. The pickup force allows the plug retainers to pivot to release a dart and at the same time at least obstruct a flow bypass that allowed flow around the dart before it was released. During running in and until the dart is released the tool components are rotationally locked at a first location and the lock at the first location releases when the plug is launched with an axial pick up force. Further picking up aligns a trapped ball in an axial slot in a mandrel with a mandrel exit hole where relative rotation then can cam the ball toward the exit hole and into the mandrel bore. The released ball can be a backup to set the same tool the dart was intended to set or it can set another tool altogether. The further axial movement to release the ball also engages an upper rotational lock to allow torque transmission for operation of other tools. 
     Those skilled in the art will more readily appreciate additional aspects of the present invention from a review of the detailed 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 drop multiple objects to landing locations in a tubular string. The tool can keep at least one ball out of the fluid stream until ready for release. A dart or wiper plug can be kept in the fluid stream with an open bypass until axial mandrel movement allows release of the plug or dart. The tool is rotationally locked at a lower location for run in and then can rotationally lock at an upper location upon release of the dart or ball. Axial movement that releases the dart can continue until the ball aligns with a decreasing depth groove so that relative part rotation cams the ball against a leaf spring detent and into the mandrel flow path. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a section view of the tool during running in; 
         FIG. 2  is the view of  FIG. 1  with an initial pickup force and before the dart is released; 
         FIG. 3  is the view of  FIG. 2  with the dart released from further picking up; 
         FIG. 4  is the view of  FIG. 3  with the ball aligned with an exit port in the mandrel so rotation can cam the ball into the mandrel using a decreasing radius surface; 
         FIG. 5  is an enlarged view of a portion of  FIG. 1 ; 
         FIG. 6  is a perspective run in view at a lower end of the mandrel showing rotational locking between the mandrel and a surrounding sleeve; 
         FIG. 7  is the view of  FIG. 6  after a pickup force that releases the dart showing the release of the lower rotational locking; 
         FIG. 8  is a perspective view near the top of the mandrel showing the upper rotational locking feature disengaged; 
         FIG. 9  is the view of  FIG. 8  after picking up to release the dart showing the upper rotational lock engaged; 
         FIG. 10  is a perspective see through run in view showing the ball retained in the groove that has a decreasing radius and in an offset position from the exit port; 
         FIG. 11  is the view of  FIG. 10  showing alignment of the ball with the mandrel exit port so that relative rotation cams the ball through the exit port overcoming a spring detent; 
         FIG. 12  is the view of  FIG. 11  with the ball in the deepest part of the groove before relative rotation has started; 
         FIG. 13  is the view of  FIG. 12  showing how rotation has cammed the ball past the detent so the ball can exit into the mandrel bore. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 1  the relevant portions of the tool are illustrated. In the preferred embodiment a liner that is not shown is being cemented and the dart or wiper plug  10  is supported in the flow path  12  of the mandrel  14  by pivoting retainers  16  and  18 . Looking at  FIG. 5  for an enlarged view, it can be seen that in the run in position of FIGS,  1  and  5  the pivoting retainers  16  and  18  have an end  20  that abuts surface  22  of the middle sleeve assembly  24  such that rotation about the pivot pin  26  cannot happen. Middle sleeve assembly  24  has an upper member  28  that is connected to lower member  30  at thread  32 . Mandrel  14  is pinned to upper member  28  at pin or pins  35  for run in. There is a flow bypass around the plug  10  with an entrance at  34  and an exit at  36  in an annular path  38  between the mandrel  14  and the middle sleeve assembly  24 . Upon raising the mandrel  14  the recesses  40  and  42  align with the ends  20  so that the retainers  16  and  18  can both pivot to release the plug  10 . The reason for the two retainers  16  and  18  is to hold the plug  10  in position against flow that can come in opposed directions. When the retainer  16  pivots to the release position that is shown in  FIG. 3  it obstructs the exit  36  sufficiently to let applied pressure and the weight of the plug  10  to start the plug  10  moving downhole until it clears the exit  36  so that the plug can then be pumped the rest of the way to its intended destination downhole. 
     Also in the run in position there is a ball  44  that is located in a circumferential groove  46  as better seen in  FIG. 10 . The bottom surface  48  of the groove  46  that is located in lower member  30  has a decreasing radius. The ball  44  is initially at an end of an axial slot  50  that terminates in an exit opening  52  that is sized bigger than the diameter of the ball  44 . The slot  50  allows the mandrel  14  to be lifted while the ball  44  is retained substantially within the wall of lower member  30 . At the end of the axial movement of the mandrel  14  the ball  44  is in registry with the opening  52  but still retained out of the mandrel passage  12  by a schematically illustrated detent  54  that is best see in  FIG. 12  where the ball  44  is shown in the largest diameter of groove  46 . It can be seen that relative rotation of the mandrel  14  with respect to the lower member  30  will advance ball  44  along the decreasing radius of bottom surface  48 . Since the ball  44  at the time the relative rotation starts is axially aligned with opening  52  the result of the relative rotation will be to cam the ball  44  through the detent  54  allowing the ball to release into passage  12  to its ultimate destination further downhole. The detent  54  is schematically illustrated in  FIG. 13  as having been pushed out of the way so that the ball  44  is free to fall into the passage  12  where it can travel by gravity or by being pumped to its end destination on a ball seat (not shown) that can then be used to pressure up to operate the same tool as the plug  10  was supposed to operate as a backup feature or some completely distinct tool can be operated with a landed ball  44 . 
     Referring back to  FIGS. 1-4  the general sequence of operation is that the outer sleeve  56  is fixed in the wellbore such as with an attached packer that is not shown. The mandrel  14  is raised axially until the retainers  16  and  18  mounted to respective pivot pins  26  rotate when the recesses  40  and  42  have been raised to align with the ends  20 . Before this happens the shear pin or pins  34  break so that the mandrel  14  is no longer restrained to move axially in tandem with the sleeve assembly  24 . The shear pin or pins  35  break in the  FIG. 3  position when the top end  57  of member  28  hits the drag block housing  58  that is supported by outer sleeve  56  which is in turn otherwise fixed in the wellbore with a packer or anchor that is not shown and the mandrel  14  is further pulled up with additional force. That same  FIG. 3  position now has the ball  44  aligned with port  52  so that a subsequent rotation of the mandrel  14  while the sleeve assembly  24  is held against rotation by the meshing of teeth  60  and  62  ejects the ball  44  into the passage  12 . This is best seen when comparing  FIG. 8  for the run in position and  FIG. 9  for the meshed position of teeth  60  and  62  so that the sleeve assembly  24  is held fixed as the rotation of mandrel  14  ejects the ball  44  to the passage  12 . The splines  66  and  68  release as upward movement of the mandrel  14  moves the travel stop  64  against the bottom of the sleeve assembly  24  and pushing the sleeve assembly  24  against teeth  62  to again rotationally lock the sleeve assembly against rotation so that mandrel  14  rotation will expel ball  44 . The meshed splines  66  and  68  insure that the ball  44  that rides on decreasing radius surface  48  will not jam the mandrel  14  to the sleeve assembly  24  until it is time to eject the ball  44  with rotation. 
     Referring to  FIGS. 1 and 6  there is a travel stop assembly  64  on the mandrel  14  as well as a spline  66  that meshes with spline  68  that is internal to the sleeve assembly  24 . The splines  66  and  68  are engaged for run in to rotationally lock the mandrel  14  to the sleeve assembly  24 . As the mandrel  14  is picked up, the splines  66  move away from engagement from splines  68  and the teeth  60  and  62  ultimately mesh as the plug  10  is released and rotation then cams out the ball  44  into the mandrel passage  12 . Picking up the mandrel  14  will cause the sleeve assembly  24  to bottom on the travel stop  64  such that further raising of the mandrel  14  will bring teeth  60  and  62  together such that subsequent mandrel  14  rotation as the sleeve assembly  24  is held against rotation by the meshed teeth allows camming out of ball  44 . 
     Those skilled in the art will appreciate that the present invention allows bringing balls or plugs close to their ultimate destination before release. The plug that is in the mandrel flow path is bypassed for normal circulation flow and the plug is retained in position against flow in the mandrel passage in either one of two opposed directions. The mandrel is rotationally locked to the surrounding sleeve for run in with splines that separate as the mandrel is picked up. Picking up the mandrel allows the retainers for the plug to pivot out of the way with one of the retainers moving over one of the bypass ports to aid the plug in its initial movement beyond the bypass so that its own weight or pressure above can deliver the plug to the desired location. 
     While the mandrel and the surrounding sleeve assembly are initially pinned for tandem movement, picking up the mandrel releases the lower splines between the two and with a bottom travel stop on the mandrel brings the surrounding sleeve assembly to an upper travel limit where teeth mesh to retain the sleeve assembly against rotation while the mandrel can be turned to cam out a ball into the mandrel passage by pushing the ball past a bias and along a decreasing radius arc on a now stationary sleeve assembly and through a port that has come into alignment with the ball as a result of raising the mandrel. 
     While a single ball is shown as being released additional balls can also be used as well as multiple plugs by just adding additional facilities as those that are described for the ball and plug that are illustrated. While a cement application for a liner hanger is the preferred application, other completion or drilling applications are envisioned. While a plug and ball dropper are illustrated, they can be used separately depending on the application. 
     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: