Abstract:
A tool and associated method allows a liner top to be dressed. Then while maintaining a lateral port closed the tool can be used to circulate while being rotated and reciprocated. The tool features discrete j-slot mechanisms. The upper j-slot allows the lateral port to initially open while the lower j-slot keeps the lateral port open despite movement of the tool in opposed directions in the hole due to a barrier to the pin in the lower j-slot. When enough weight is set or the barrier is otherwise removed, the lateral port can be closed and the test packer set by set down weight with the lateral port closed. After the packer is unset the lateral ports can be reopened and circulation and swiveling on a bearing can occur even if the packer is temporarily actuated from the setting down motion that reopened the lateral ports.

Description:
PRIORITY INFORMATION  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/809,378, filed on May 30, 2006. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The field of the invention is well cleanup tools that allow a tubular top to be dressed, the mud conditioned or displaced in the liner, and above the liner through lateral ports, as well as setting a packer to test integrity of the cementing of the tubular.  
       BACKGROUND OF THE INVENTION  
       [0003]     In well completions a liner is typically inserted in the drilled wellbore and cemented. Thereafter the integrity of the cementing needs to be tested and that is accomplished with a pressure test using a packer set above the liner top. To avoid damage to tools that may be later set in the liner, the top of the liner needs to have a relatively burr free internal surface. Typically, a mill is used to dress the liner top. It is advantageous to condition the mud above the liner and to do it with relatively high circulation rates. To accomplish that a tool with a lateral port has been used that can open, when needed to allow conditioning.  
         [0004]     Typically, these ported tools involve a ported mandrel in a ported housing where the ports can be selectively put into alignment for flow and misalignment to close off flow. In the past the required relative movement to go between the open and closed positions has been accomplished with j-slot mechanisms that involve relative movement between a pin on one part and a slot on the other. Progress of the pin in the slot could be obtained by cycling pressure on and off that forced relative movement between a j-slot sleeve and a lug to advance the lug in a j-slot track or by mechanical movement of the pin or slot with the other held supported. For example a mandrel with a pin extending into a slot on a surrounding housing that is supported in the well could allow the mandrel to take several positions with respect to the surrounding housing. That relative movement could result in aligning or misaligning of ports. The limitations of such j-slot mechanisms are that the pin continues to progress in the slot if there is reciprocating movement of the tool for other purposes. In that case if aligned ports were needed to stay aligned during reciprocating tool movement for another purpose such as conditioning the mud through a lateral port while reciprocating the tool the length of tubulars that can be assembled on a rig floor, for example about 90 feet, the j-slot mechanisms would not assure that the aligned ports would not go to a misaligned position and thus nullify the mud conditioning effort that was in progress. Thus, one advantage of the present invention allows the lateral port to remain open for conditioning by having a barrier to the progress of the lug out of a desired slot in the j-slot while mud is conditioned above a liner top.  
         [0005]     Tools in the past have included bearings so that when weight was set down on the bearing the mandrel could rotate with ports in the mandrel selectively aligned with ports in the housing, as long as weight was set down. This rotation of the mandrel feature allowed better agitation of the mud as different outlets around the circumference of the outer housing saw flow in turn as the mandrel rotated. The problem was that if the tool was moved longitudinally back and forth from the position it took to align the ports such as if the span of the conditioning zone was 90 feet, for example, the j-slot device would cycle and the ports may no longer stay aligned.  
         [0006]     What was needed in a cleanup and test tool of this type is an ability to open the lateral ports and hold them open while the tool is cycled up and down for a long distance and then later be able to close them. Another desirable feature was to be able to later still open the ports and circulate and swivel before pulling the tool out of the hole. These and other features of the present tool and associated method of the present invention will be more readily apparent to those skilled in the art from a review of the detailed description and the associated drawings and the claims below that define the full scope of the invention.  
       SUMMARY OF THE INVENTION  
       [0007]     A tool and associated method allows a liner top to be dressed. Then while maintaining a lateral port closed the tool can be used to circulate while being rotated and reciprocated. The tool features discrete j-slot mechanisms. The upper j-slot allows the lateral port to initially open while the lower j-slot keeps the lateral port open despite movement of the tool in opposed directions in the hole due to a barrier to the pin in the lower j-slot. When enough weight is set or the barrier is otherwise removed, the lateral port can be closed and the test packer set by set down weight with the lateral port closed. After the packer is unset the lateral ports can be reopened and circulation and swiveling on a bearing can occur even if the packer is temporarily actuated from the setting down motion that reopened the lateral ports. 
     
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
       [0008]      FIGS. 1   a - 1   c  show the tool in the run in position;  
         [0009]      FIGS. 2   a - 2   c  shows the tool with the lateral port open position where the tool can be swiveled, reciprocated and circulated with the lateral ports remaining open;  
         [0010]      FIGS. 3   a - 3   c  show the tool with the lower j-slot disabled and the tool in position to swivel on the bearing to displace mud from above the packer;  
         [0011]      FIG. 4  is a section through the upper pin of the upper j-slot taken along lines  4 - 4  of  FIG. 1   a;    
         [0012]      FIG. 5  is a layout of the upper j-slot;  
         [0013]      FIG. 6  is a layout of the lower j-slot;  
         [0014]      FIG. 7  show a section of a snap ring alternative, in the run in position, to the lower j-slot shown in  FIG. 6 ;  
         [0015]      FIG. 8  is the view of  FIG. 7  with the snap ring securing the ports open position and the mandrel picked up;  
         [0016]      FIG. 9  is the view of  FIG. 7  with the mandrel set down;  
         [0017]      FIG. 10  is the view of  FIG. 9  with weight set down moving the shear ring and allowing the snap ring to snap in further for a release between the mandrel and the outer assembly so the ports can close;  
         [0018]      FIG. 11  shows an alternative to using the shear ring  114  pinned by pins  116  in a design that lets the lateral flow ports be held open more than a single time. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0019]     Referring to  FIGS. 1   a - 1   c  the tool has a multipart mandrel M made up of top sub  10  having a thread  12  to which the work string (not shown) is attached for manipulation of the mandrel M. Upper mandrel  14  is connected to top sub  10  at thread  16  that is sealed with seal  18 . Upper mandrel  14  has a bushing  15  that rides inside of upper sleeve  54 . Port sub  20  is connected to upper mandrel  14  at thread  22  that is sealed by seal  24 . Port sub  20  has one or more ports  26  around its circumference and ports seals  28  and  30  straddle ports  26 . Lower mandrel  32  is attached to port sub  20  at thread  34  that is sealed by seal  36 . Bottom sub  40  is secured to lower mandrel  32  at thread  38  that is sealed by seal  39  and retains one or more radially inwardly oriented lugs  42  that extend through the lower mandrel  32 . Referring back to  FIG. 1   a  and  FIG. 4 , upper mandrel  14  has one or more radially outwardly oriented lugs  44  that are part of the upper j-slot assembly as will be later described. Lugs  42  are part of the lower j-slot assembly as will be later described. The various parts of the mandrel M have now been described. Next, the outer assembly O will be described in great detail.  
         [0020]     The outer assembly O begins with a top sub  46  that has a bushing  48  that rides on upper mandrel  14 . Upper sleeve  54  is secured at thread  52  to top sub  46 . Upper j-slot sleeve  56  is secured at thread  58  to top sub  46 .  FIG. 5  shows a rolled flat view of upper j-slot sleeve  56  with lug  44  in the several positions that it can take along track  60 . In the section view of  FIG. 1   a  the upper j-slot sleeve  56  is seen disposed on both sides of lug  44 . Upper sleeve  54  has a series of openings  62 ,  64 ,  66  and  68  that prevent liquid lock between the mandrel M and the outer assembly O. Seals  28  and  30  on the mandrel M engage surface  70  on upper sleeve  54  to keep port  26  closed for run in. Upper sleeve  54  also has a port  72  that is capped shut for run in by sleeve  74  retained by a shear pin  76 .  
         [0021]     Lower sleeve  78  is connected to upper sleeve  54  at thread  80  and sealed at  82 . Lower sleeve  78  traps retainer  84  between itself and sleeve  54 . Retainer  84  supports part of a z-shaped shear ring  86  to sleeves  54  and  78  while a shoulder  88  on lower mandrel  32  rests on shear ring  86  for run in for reasons that will be explained below. Bottom sub  90  is secured to lower sleeve  78  at thread  92  and sealed by seal  94 . Opposed surfaces  96  on bottom sub  90  and  98  on lower sleeve  78  contain bearing assembly B that will be described below.  
         [0022]     The lower j-slot sleeve  100  has a track  102  that is shown in rolled out form in  FIG. 6  along with lug  42  that travels track  102 . Bearing retainer  104  is secured to lower j-slot sleeve  100  at thread  106 . Retainer  104  has a rib  108  with bearings  110  and  112  above and below rib  108  respectively. A shear ring  114  is pinned by pin  116  to lower j-slot sleeve  100  for purposes that will be explained when the operation is reviewed.  
         [0023]     The major parts of the tool now having been described, the operation will be reviewed in greater detail. While not shown, those skilled in the art will appreciate that supported at thread  118  on bottom sub  90  is a string that extends into the liner that has been hung off a higher casing that has been cemented. That string supports the mill by extending through it and goes to close to the liner bottom. That string also supports a packer above the mill that is used to dress the liner top so that it later can accept a packer connected to a production string. The packer that is used with this tool is set in the casing above the liner for a test to determine if there is fluid loss into the formation when pressure is applied against the set packer.  
         [0024]     In operation, the tool shown in  FIGS. 1   a - 1   c  is lowered into position and the mill (not shown) is used to dress the liner top. After that the tool with the pipe extending from thread  118  is rotated and reciprocated while fluid in the liner is conditioned. During this operation the outer assembly O may be put into a supported position off the liner top but care is taken to avoid loading the mandrel M to the point that shoulder  88  shears the z-shaped shear ring  86 . With ring  86  intact, the mandrel M cannot move with respect to the outer assembly O. The next step is to condition the mud above the liner top. For this operation, the outer assembly O is lowered to a supported position off the liner top and weight is set down on the mandrel M to the point that shoulder  88  breaks the shear ring  86 . The downward movement to break the shear ring  86  has lug  44  moving from position  120  to position  122  in track  60 . There the weight of the string above the tool is on lugs  44  as position  122  traps lugs  44  in upper j-slot sleeve  56 . At the same time lug  42  simply moves down in track  124  but not quite to the point shown in  FIG. 6 .  
         [0025]     Next the mandrel M is picked up and rotated right while being let down. This movement takes lug  44  along the slanted path shown at the top of  FIG. 5  and out of upper j-slot sleeve  56  to let the mandrel M descend further since lugs  44  are free from being trapped in position  122 . The mandrel can then descend until its bottom sub  40  engages the shear ring  114  but does not break the shear pins  116  that retain it to lower j-slot sleeve  100 . While this movement is going on, the lugs  42  continue their descent in track  124  shown in  FIG. 5 . The turning of the mandrel M to get lugs  44  out of upper j-slot sleeve  56  simply has the effect of rotation of lower j-slot sleeve  100  by lugs  42  as they travel down track  124 . At the time when bottom sub  40  of mandrel M hits the shear ring  114 , the lugs  42  have just reached ramp  128  at the bottom of track  124 , as shown in  FIG. 6 . There is still enough mandrel movement left at that point before engaging the shear ring  114  so as to allow lugs  42  to go down ramp  128  into track  126  that is a very short track parallel to track  124 . Those skilled in the art will appreciate that the movement of the mandrel M to the just described position aligns ports  72  and  26  so that high flow circulation can take place through those aligned ports while the tool is reciprocated and rotated. There is no rotation of the outer assembly O because bearings  110  and  112  allow for such relative rotation. With the shear ring  114  in place lugs  42  can&#39;t escape track  126  and despite the relative longitudinal motion allowed by lugs  42  moving from one end to the other of track  126 , the ports  26  and  72  maintain sufficient longitudinal alignment for high flow rate circulation despite tool reciprocation and rotation of mandrel M. This position of the tool is shown in  FIGS. 2   a - 2   c.  In this position the mud above the liner top can be conditioned as the tool is used for circulation while it is picked up and set down with the mandrel M rotating. Again there is the assurance of aligned ports  72  and  26  to permit circulation despite the up and down movements or mandrel M rotation.  
         [0026]     Those skilled in the art will appreciate that the present invention encompasses other ways to retain the tool in the desired position during this step than using a j-slot with a feature to temporarily trap a lug in a j-slot. In fact, the use of a temporary block of a lug in a j-slot is not limited to circulation tools discussed above but rather has broad applications to other downhole tools. Additional features can be added to the above described tool to protect the shear pins  116  from breaking early. For example, another sleeve with a ball seat can be placed in a supporting position to the ring  114  so that pins  116  can&#39;t shear until a ball lands on a seat of a supporting sleeve to move it away from supporting ring  114  so that impact can then break pins  116  in the manner that will be described below. Yet other types of temporary retaining devices can be used instead of the ring  114  interfering with movement of lug  42  in j-slot sleeve  100  as will be described below. The procedure being described herein can be modified to even eliminate the lower j-slot sleeve  100  and the associated lug  42 , if desired.  
         [0027]     When the conditioning of the mud above the liner top is concluded, weight is set down on mandrel M to break shear pins  116  and doing so lets the shear ring  114  drop down onto the bearing  110 , as shown in  FIG. 3   c.  Because the ring  114  is displaced, the lug  42  can exit short track  126  as shown in the bottom of  FIG. 6 . At that point a pickup force on mandrel M will bring lug  42  up the next track  124 ′. As that is happening, lug  44  will enter track  60  guided by tapered surfaces  130  and  132 , as shown in  FIG. 5 . Lug  42  will first hit the upper position  120  and after weight is set down on mandrel M will settle into position  122 . At this point the ports  26  and  72  will be misaligned and isolated as the tool assumes the run in position of  FIG. 1 , with the main difference being that shear pins  116  and shear ring  86  are now both broken.  
         [0028]     However, before setting down weight to get lug  44  in position  122  displacing fluid can be pumped through the tool into the liner to displace the mud out of it and position the displaced mud at a location above where the packer (not shown) will be set to test the cement integrity of the liner. When the displacing is done then the mandrel is lowered without rotation to set the packer. Here lug  44  will be in position  122 . After the test with the packer is completed, the packer is unset by picking up on mandrel M which engages surface  134  of upper mandrel  14  to top sub  46  of the outer assembly O pulling up the outer assembly O and stretching out the packer to release it. This engagement can be seen in the run in position in  FIG. 1   a.  The liner can then be circulated through the string extending through it that is supported at threads  118 . The mandrel M can then be set down while being rotated right to allow lug  44  to exit track  60 . At this point the tool will be in the position of  FIGS. 3   a - 3   c.  The ports  72  and  26  will be aligned and the mandrel M will rest on ring  114  which in turn will rest on bearing  110 . At this point the mud that was earlier conditioned above the packer can be displaced from the hole while the mandrel M is rotated on bearing  110  without being picked up since at this point picking up will misalign ports  72  and  26 . The tool can then be pulled out of the hole.  
         [0029]     Those skilled in the art can appreciate that the tool can save the operator rig time in that the mud conditioning can be done above the liner top in a shorter period of time if the drill string is rotated and reciprocated up and down during circulation while still retaining the flexibility to close the ports for mud displacement from the liner and open them again for displacement of mud from above the packer after the cement integrity test.  
         [0030]     Referring now to  FIGS. 7-10  there is illustrated an alternative embodiment to the use of the lower j-slot sleeve  100 . In this embodiment the bottom sub  40  of mandrel M has a recess  136  that carries a snap ring or equivalent device that stores energy  138 . In the run in position that this Figure illustrates, the snap ring  138  is prevented from collapse by sleeve  100 ′ that this time has a single straight slot (not shown) that lug  42  rides in. When lug  44  is brought out of upper j-slot sleeve  56  as previously described, the bottom sub  40  of mandrel M brings down lug  42  and snap ring  138  until the snap ring  138  lines up and snaps into groove  140  that is defined by shoulder  142  and the lower end of sleeve  100 ′. This position is illustrated in  FIG. 8 . In this position, the mandrel M including the lug  42  is prevented from moving up the not shown groove in sleeve  100 ′ by shoulder  142 . The mandrel M is prevented from moving down by the presence of shear ring  114  held by shear pins  116 . In  FIG. 8  the mandrel M is pulled up showing a gap between bottom sub  40  and ring  114 . In  FIG. 9  weight is set down on the mandrel M closing that gap with the pins  116  still intact. After the conditioning step above the liner top is concluded involving circulation, picking the mandrel M up and setting it down while rotating it, the mandrel M is set down hard enough to break shear pins  116  to allow ring  114  to move down as shown in  FIG. 10 . In this position, snap ring  138  is clear of surface  146  on the mandrel M since it is in lower groove  144  in sleeve  100 ′.  
         [0031]     Referring now to  FIG. 11  there is shown a structure that can replace the ring  114  and associated pins  116 . With the ring and pins design, the lug  42  can be trapped in track  126  to hold the ports  26  and  72  aligned while the mandrel M is picked up or set down and rotated. It isn&#39;t until the pins  116  are broken that lug  42  can exit track  126  to allow the mandrel to come up to the point where the ports  26  and  72  are no longer in flow communication. In that version, once the pins  116  are broken, the alignment of ports  26  and  72  can no longer be secured. Thus only weight being set down on mandrel M after pins  116  are broken will keep those ports aligned. The  FIG. 11  design operates to keep the lug  42  in track  126  by landing bottom sub  40  of mandrel M on ring  148  that is biased by a stack of Belleville washers or an equivalent bias force  150 . The operation to retain the lug  42  in track  126  is the same as using the ring  114 . As long as the contact force on ring  148  is not excessive, it will not move and lug  42  will not be able to exit from track  126 . However, if enough downward force on mandrel M is applied, the ring  148  is displaced as washers  150  are compressed and the lug  42  can move out of short track  126 . The difference is that the washers  150  force the ring  148  back to its original position against shoulder  152  to allow the trapping of lug  42  in track  126  a multiple number of times rather than just once as the design using ring  114  with pins  116  would allow.  
         [0032]     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.