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 shifting relative rotation capabilities to different members. Axial movement that releases the dart also aligns a ball with a decreasing depth groove so that relative part rotation can cam the ball against a leaf spring detent and into the mandrel flow path.

Description:
FIELD OF THE INVENTION 
       [0001]    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 
       [0002]    Devices that drop balls and darts are used in a variety of applications. For example in cementing the darts are used to wipe drill pipe 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. 
         [0003]    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. 
         [0004]    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. 
         [0005]    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 obstruct a flow bypass that allowed flow around the dart before it was released. While 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. During the pickup to release the dart a trapped ball in an axial slot in a mandrel is aligned 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. 
         [0006]    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 
       [0007]    A subterranean tool can drop multiple objects to landing locations in a tubular string. 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 can also keep an additional ball out of the fluid stream until ready for release by rotation of the mandrel. The tool is rotationally locked at a lower location for run in and then can rotationally lock at an upper location prior to release of the primary dart or ball. The ball is stored in a decreasing depth groove and mandrel slot until axial movement that releases the dart also aligns the ball with a mandrel exit hole so that relative part rotation cams the ball past a leaf spring detent and into the mandrel flow path. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a section view of the tool during running in; 
           [0009]      FIG. 2  is the view of  FIG. 1  with an initial pickup force and before the dart is released; 
           [0010]      FIG. 3  is the view of  FIG. 2  with the dart released from further picking up and the ball aligned with an exit port in the mandrel; 
           [0011]      FIG. 4  is the view of  FIG. 3  with the ball aligned with an exit port in the mandrel after rotation has cammed the ball into the flow path using a decreasing radius surface; 
           [0012]      FIG. 5  is an enlarged view of a portion of  FIG. 1 ; 
           [0013]      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; 
           [0014]      FIG. 7  is the view of  FIG. 6  after a pickup force that releases the dart and align the ball with the exit hole showing the release of the lower rotational lock; 
           [0015]      FIG. 8  is a perspective view near the top of the mandrel showing the upper rotational locking feature disengaged; 
           [0016]      FIG. 9  is the view of  FIG. 8  after picking up to release the dart and align the ball with the exit hole showing the upper rotational lock engaged; 
           [0017]      FIG. 10  is a perspective see through run in view showing the ball retained in the groove that has a decreasing radius and in the axial groove in the mandrel in an offset position from the exit hole; 
           [0018]      FIG. 11  is the view of  FIG. 10  showing alignment of the ball with the mandrel exit hole so that relative rotation is able to cam the ball through the exit hole overcoming a spring detent; 
           [0019]      FIG. 12  is the view of  FIG. 11  with the ball in the deepest part of the groove before relative rotation has started; 
           [0020]      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 
       [0021]    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 or ball  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 be pivoted by torsion springs  17  and  19  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  and  18  pivot to the release position that is shown in  FIG. 3  it obstructs the exit  36  and entrance  34  respectively sufficiently to let applied pressure and the weight of the plug  10  to start the plug  10  moving downhole until it clears the hole  52  so that the plug can then be pumped the rest of the way to its intended destination downhole. 
         [0022]    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 groove  46  that is located in lower member  30  has a decreasing radius that ends at the bottom surface  48 . The ball  44  is initially at an end of an axial slot  50  that terminates in an exit hole  52  that is sized bigger than the diameter of the ball  44 . The slot  50  allows the mandrel  14  to be manipulated while the ball  44  is retained substantially within the wall of lower member  30 . The slot  50  also allows for the mandrel  14  to be axially shifted within the lower member  30 . In addition to the slot  50  on the mandrel  14  and the groove  46  on the lower member  30 , there is a spline  66  on the mandrel  14  that meshes with a spline  68  that is internal to the lower member  30 . The splines  66  and  68  are engaged for run in to rotationally lock the mandrel  14  to the sleeve assembly  24  in order to not jam the ball  44  in the slot  50 . As the mandrel  14  is axially shifted, the splines  66  are disengaged from splines  68  and the ball  44  is shifted into registry with the opening  52  but still retained out of the mandrel passage  12 . The ball  44  is retained by a detent  54  that is best seen 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  past the detent  54  allowing the ball to release into passage  12  so it can travel to its ultimate destination further downhole. The detent  54  is shown 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 as a backup feature to pressure up and operate the same tool as the plug  10  was supposed to operate or some completely distinct tool can be operated with a landed ball  44 . 
         [0023]    Referring back to  FIGS. 1-4  the general sequence of operations begin when the outer sleeve  56  is fixed in the wellbore such as with an attached packer or other device that is not shown. Initially the mandrel  14  is restrained to move axially in tandem with the sleeve assembly  24  by the shear pin or pins  35 . The mandrel  14  is raised axially until 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. When the top end  57  of member  28  hits the drag block housing  58  the teeth  60  and  62  seen in  FIG. 8  and  FIG. 9  interlock. During the process of teeth  60  and  62  meshing internal mechanisms are triggered in the drag block housing  58  which allow the drag blocks  63  to be released and grip the casing to increase torsional drag. At this point both mandrel  14  and sleeve assembly  24  as well as sleeve assembly  24  and outer sleeve  56  are rotationally locked. Applying additional lifting load on the mandrel will cause the shear pin or pins  35  to break so that the mandrel  14  is no longer restrained to move axially in tandem with the sleeve assembly  24 . Once the mandrel  14  and sleeve assembly  24  are no longer locked together several actions take place with two stages of motion of mandrel  14 . The first stage of motion of the mandrel  14  is additional axial movement until the travel stop  64  shoulders against the bottom of the lower member  30  of the sleeve assembly  24  seen in  FIG. 3 . The second stage of motion of the mandrel  14  is rotation seen in  FIG. 4 . During the first stage of mandrel  14  manipulation three separate actions take place simultaneously. Firstly, the retainers  16  and  18  mounted to respective pivot pins  26  rotate when their respective ends  20  align with the recesses  42  and  40 . Secondly, the ball  44  aligns with port  52  so that a subsequent rotation of the mandrel  14  ejects the ball  44  into the passage  12 . Thirdly, the splines  66  and  68  release, and the rotational lock between the mandrel  14  and the sleeve assembly  24  is removed. This third action allows the mandrel  14  to have relative rotation within the sleeve assembly  24  and the outer housing  56  enabling the second stage of mandrel  14  manipulations. The second stage of manipulation is made possible because the travel stop  64  against the bottom of the sleeve assembly  24  retains the meshed position of teeth  60  and  62  so sleeve assembly  24  is held fixed as the rotation of mandrel  14  ejects the ball  44  to the passage  12 . 
         [0024]    Those skilled in the art will appreciate that the present invention allows bringing a plug and a ball or multiple balls 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 moving them over 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. 
         [0025]    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. 
         [0026]    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. 
         [0027]    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: