Abstract:
A modular pressure operated actuator can be coupled with a downhole tool to selectively operate it at least once. In the preferred embodiment the module can be mounted adjacent an isolation valve and after a fixed number of on and off pressure cycles allow a spring to push an actuator to operate the valve to an open position. The actuator, in another embodiment, can be reset with a tool run into the module to move the actuator back against a power spring and hold that spring force until the pressure cycling begins again. The preferred application is for a formation isolation ball valve but other valves, such as sliding sleeves, or other types of downhole tools can be actuated with the module that permits a retrofit of a hydraulic operation to a heretofore purely mechanically actuated tool.

Description:
FIELD OF THE INVENTION 
       [0001]    The field of the invention is a modular hydraulic assembly that can be coupled to an otherwise mechanically operated tool and preferably a valve to allow the option of hydraulically opening the tool or valve once or multiple times. 
       BACKGROUND OF THE INVENTION 
       [0002]    Different valve styles have been used downhole. One type is a sliding sleeve valve that can selectively cover or open holes in a casing or liner string. These valves are typically shifted with a shifting tool that grabs a recess in the sleeve and pulls or pushes the sleeve to open or close the wall ports in the tubular. Some examples are U.S. Pat. Nos.: 5,549,161; 7,556,102 and 7,503,390. 
         [0003]    Formation isolation valves have been used that have a ball that is attached to a sleeve so that movement of the sleeve results in ball rotation between open and closed position. These valves typically included a piston responsive to tubing pressure that worked in conjunction with a j-slot mechanism. The valve was closed mechanically but could be opened once with a predetermined number of pressure cycles on the piston. Eventually, a long slot in the j-slot would be reached to allow a spring or a compressed gas reservoir to move an operating sleeve into another sleeve that was attached to the ball so that the ball could be rotated to the open position. In one design the ball was locked after moving into the open position but that lock could be overcome with another tool run downhole. There was also a provision for an emergency opening with a pressure tool if for some reason the pressure cycles failed to open the ball. This design is illustrated in U.S. Pat. No. 7,210,534. Other formation isolation valves that came as an assembly of a mechanically operated ball that had the option of opening with pressure cycles until a j-slot allowed a pressurized chamber charged to a known specific pressure to move an operating sleeve against another sleeve to get the ball to turn open are illustrated in U.S. Pat. Nos. 5,810,087 and 6,230,807 while U.S. Pat. No. 5,950,733 initiates opening the ball with pressure that breaks a rupture disc to liberate pressure previously stored to move a sleeve to open that valve. 
         [0004]    These combination valves with the hydraulic open feature bundled into a mechanical valve such as a ball valve are very expensive and in many applications represent overkill because a manually operated barrier valve such as with a shifting tool run in on coiled tubing, for example would be sufficient and within the budget for the particular project. On the other hand, the specification for some projects changes where the previously ordered manual barrier valve is determined to be insufficient for the application without a hydraulic opening feature. A hydraulically operated module of the present invention addresses this need for flexibility and further makes it possible for use of the module on a variety of tools when those tools can respond to shifting of an operating rod. The hydraulic module further incorporates either a onetime only configuration which is the simpler variation or another variation that can be re-cocked after an actuation with a tool run in from the surface to move the operating piston back up. The unique configuration of the cycling control assembly allows the ability to re-cock with minimal displacement of the operating rod so that the tool can be shorter because the operating rod does not need to be displaced after the valve opens any further than it takes to land a snap ring back in a groove so that the series of pressure cycles can resume when another hydraulic opening of the valve is required. These and other advantages of the present invention will become more apparent to those skilled in the art from a review of the description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is given by the appended claims. 
       SUMMARY OF THE INVENTION 
       [0005]    A modular pressure operated actuator can be coupled with a downhole tool to selectively operate it at least once. In the preferred embodiment the module can be mounted adjacent an isolation valve and after a fixed number of on and off pressure cycles allow a spring to push an actuator to operate the valve to an open position. The actuator, in another embodiment, can be reset with a tool run into the module to move the actuator back against a power spring and hold that spring force until the pressure cycling begins again. The preferred application is for a formation isolation ball valve but other valves, such as sliding sleeves, or other types of downhole tools can be actuated with the module that permits a retrofit of a hydraulic operation to a heretofore purely mechanically actuated tool. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIGS. 1   a - 1   d  are a section view of the hydraulic module that is capable of a single operation downhole; 
           [0007]      FIGS. 2   a - 2   d  are a section view of a resettable alternative embodiment shown in the position when pressure is bled off in the last cycle before the module is operated to actuate the downhole tool; 
           [0008]      FIG. 3  is a rolled flat view of the mandrel showing the j-slot pin is in the  FIG. 2  position; 
           [0009]      FIG. 4  is a rolled flat view of the exterior of the ramp sleeve that faces the indexing sleeve and the snap ring; 
           [0010]      FIG. 5  is a rolled flat overlay of the indexing sleeve and the ramp sleeve showing indexing sleeve openings that permit relative movement between them just before actuation of the downhole tool; 
           [0011]      FIGS. 6   a - 6   b  show a portion of the module in  FIGS. 2   a - 2   d  when pressured up just before opening; 
           [0012]      FIGS. 7   a - 7   b  show show a portion of the module in  FIGS. 2   a - 2   d  when pressure is starting to be released as the module is about to operate the tool; 
           [0013]      FIGS. 8   a - 8   b  show a portion of the module in  FIGS. 2   a - 2   d  when the module begins to move an actuator to operate the tool; 
           [0014]      FIGS. 9   a - 9   b  show a portion of the module in  FIGS. 2   a - 2   d  when the module has fully actuated; 
           [0015]      FIGS. 10   a - 10   b  show a portion of the module in  FIGS. 2   a - 2   d  when the module has been reset. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0016]    Referring to  FIGS. 1   a - 1   d  the module  10  has a top sub  12  connected to a mandrel  14  followed by a bottom sub  16 . Threads  18  secure the bottom sub  16  to a body  20  of the tool to be operated such as a valve. The tool  20  has an operating member  22 , which when pushed by the pushrod  24  actuates the tool  20 . In one embodiment member  22  turns a ball to open a formation isolation valve (not shown). Member  22  has a shoulder  26  for mechanical operation independent of the module  10  in opposed directions such as with a shifting tool that is run in to make contact with shoulder  26  or another shoulder (not shown) for selective movement to open or close the valve. 
         [0017]    Push rod  24  is at an end of piston  25  and piston  25  has seal  28  to seal against bore  30 . The lower end  32  is exposed to tubing pressure inside the module  10 . Above seal  28  the bore  30  is referenced to annulus pressure at  36  through passage  34  and a filter  38  to keep dirt out of passage  34 . This reference can be direct as shown or indirect using an intermediate floating piston (not shown) with a hydraulic fluid buffer so that bore  30  above seal  28  is exposed directly only to clean hydraulic fluid while from a pressure perspective the reference is still to annulus pressure at  36 . Piston  25  is secured with cap  40  to indexing housing  42 . Indexing sleeve  41  is free to rotate inside indexing housing  42  and has an inwardly oriented pin  44  that extends into a j-slot pattern  46 , such as one shown in  FIG. 3 , which is a part of the mandrel  14 . A spring  48  pushes off mandrel  14  and down against sub  50  that is secured at  52  to the indexing housing  42 . With each application of pressure to end  32  the indexing sleeve  41  goes up and down while rotating as pin  44  advances in the j-slot  46  until pin  44  comes into a long slot in the j-slot pattern  46  at which time the spring  48  pushes the piston  25  and the rod  24  against the member  22  to operate the tool that is attached to it. Movement of the indexing sleeve  41  moves fluid into or out of the annulus  36  through passage  54  that communicates with passage  34 . When the hydraulic module is not attached to the downhole tool, travel down stops when cap  40  hits bottom sub  16 , or on intermediate cycles, travel down stops when indexing sleeve  42  hits lug  43  on mandrel  14 . When the hydraulic module is attached to the downhole tool, on the final cycle, travel down stops when the valve operator shoulders in the downhole tool. This version of module  10  cannot be reset as it is a onetime operation to allow a purely mechanically operated valve to be cheaply converted to a hydraulic operation by the simple addition of a module  10  before running the assembled components downhole. The j-slot can be configured for a variety of pressure application and removal cycles before actuation. The pin  44  can be a pair of pins disposed at 180 degrees so that when there is actuation the movement is guided at the pins  44  to prevent cocking of the index sleeve  41 . It should be noted that  FIG. 3  has two long slots 6 cycles apart but that when two pins  44  are used it will take 12 cycles for both those pins to be aligned with the long slots and no other lugs blocking actuation for the actuation to happen. Depending on the number of cycles to actuation and the diameter of the components the use of blocking lugs can be eliminated and any alignment of the pins  44  with the illustrated long slots of the j-slot pattern of  FIG. 3  will result in actuation of the piston  25  and the rod  24  to operate the preferred tool and that is a 90 degree isolation ball valve. Other tools such as sliding sleeve or packers with setting sleeves, for example can be optionally set hydraulically with the module  10 . 
         [0018]    The advantage of the module  10  is that it allows more versatility in the use of tools that are adequate in some applications with only mechanical operation. However, other applications where there is a need for a hydraulic operation at least one time as an option, allows the operator to upgrade with the additional purchase and installation of the module  10 . It saves the operators with no use for the hydraulic option the expense of buying it because it has in the past been offered integrally with an otherwise mechanically operated tool. 
         [0019]      FIGS. 2   a - 2   d  are a more fully featured version of the module of  FIGS. 1   a - 1   d  and allows for a manual mechanical reset with a tool while the module is downhole so that multiple actuations are possible generally when used in a valve application, to repeatedly open a valve with pressure cycles after it has been closed mechanically. There are many similarities to the  FIG. 1  embodiment but the basic parts and movements will be reviewed again with different item numbers to avoid confusion between the embodiments. 
         [0020]    The module  60  has a top sub  62  connected to a mandrel  64 , which is connected to a bottom sub  66 . One or more rods  68  extend from respective bores  70  in bottom sub  66 . Rod  68  is connected to a respective piston  72  that has a seal  74  in bore  70 . Seal  74  defines a high pressure side at lower end  76  which is exposed to tubing pressure at  78 . On the other side of seal  74  there is a passage system  80  that leads to annulus  82  through a filter  84  to keep out debris. A part of passage system  80  goes into annular space  86  defined by outer housing  88 , which is connected at thread  90  to top sub  62 . 
         [0021]    Piston  72  is connected to indexing housing  92  at thread  94 . Indexing housing  92  is also connected at the opposite end to spring sleeve  96  at thread  98 . Spring  100  is disposed between sleeve  96  and mandrel  64 . Pressure in the tubing  78  displaces the piston  72  and with it indexing housing  92  and spring sleeve  96  so that the spring  100  is compressed. This movement is longitudinal in opposed directions with no rotation. The index housing has a shoulder  102  on which is supported the index sleeve  104  along with one or more radially inwardly oriented index pins  106  that extend into a j-slot pattern  108  on mandrel  64 . Index sleeve  104  rotates as pin or pins  106  track the stationary j-slot pattern  108  on mandrel  64 . A snap ring  110  is securely disposed between indexing sleeve  104  and spring sleeve  96  while extending into longitudinal slot  112  that has a lower end  114 . When the pressure in the tubing  78  is removed and the spring  100  is able to push down the indexing sleeve  104  that movement is stopped when snap ring  110  hits the lower end  114  of slot  112 . As best seen in  FIGS. 2   c  and  5  the indexing sleeve  104  has a discontinuous ridge  116  with breaks  118 . Ridge  116  and shoulder  120  define a groove that for a predetermined number of application and removal of pressure cycles allows the indexing sleeve  104  to take with it the ramp sleeve  122  by keeping trapped lug or lugs  124  at the lower end of the ramp sleeve  122 . The rolled out ramp sleeve  122  with lugs  124  is shown in  FIG. 4 . Ramp sleeve  122  has integral to it at its lower end, a series of collet fingers  126  that terminate in heads  130  that with pressure to the tubing  78  bled off will rest as shown in groove  131  of mandrel  64 . Mandrel  64  also has an upper groove  132 . Indexing sleeve  104  has a groove  134  facing the ramp sleeve  122 . The purpose of these grooves will be explained when the part movement is further explained in the context of the actuation. Ramp sleeve  122  has a series of spaced apart fingers  136  best seen in  FIG. 4  with tapered ends  138 . Fingers  136  ride on the mandrel  64  in slots lower than groove  112 . The purpose of the tapered ends  138  is to cam the snap ring  110  out of groove  112  so that at the proper time the lower end  114  of groove  112  will not act as a travel stop when pressure is taken off the tubing  78  and the spring  100  is pushing down the indexing sleeve  104  when its pin  106  is in the long slot  140  of j-slot  108 . 
         [0022]    For all the cycles where there will be no actuation by extension of the rod  68  a sufficient distance to operate the tool that is mounted below it,  FIGS. 2   c  and  2   d  represent the parts in the position where the pressure is bled from the tubing  78 .  FIGS. 6   a  and  6   b  generally represent the part configurations when pressure is applied to tubing  78 . Comparing the two it can be seen that index sleeve  104  and its pin or pins  106  have moved up in j-slot  108  to position  142  in  FIG. 3 . The ramp sleeve  122  has moved up with index sleeve  104  but unlike index sleeve  104  the ramp sleeve  122  has not rotated while the index sleeve has rotated to get from position  144  to position  142  in the j-slot  108 . The collet heads  130  are now in groove  132 . Groove  134  has shifted up with the indexing sleeve  104 . Note that in this pressure up cycle as in the previous pressure up cycles that did not lead to actuation when pressure was bled off, the collet heads  130  are not trapped in groove  132  but are free to break loose upon application of a downward force to the ramp sleeve  122 . However, since  FIG. 6  represents the final pressure up cycle before tool operation, it should be noted that the ridge  118  is no longer in registry with lug  124  but instead the opening  118  is now there. What this means is that when pressure is relieved after the  FIG. 6  position is obtained, there will not be a downward force from ridge  118  on lug  124  as in all the previous pressure cycles. Note also that line  146  represents an upward travel stop to the indexing sleeve  104  that is shown schematically as it is located in a rotated section from the section being shown. Note also that snap ring  110  has moved up from the downward travel stop  114  in groove  112 . 
         [0023]    After the position of  FIG. 6  is reached the pressure in the tubing  78  is bled off and  FIG. 7  illustrates the next movement of the parts. As the applied pressure is bled off, the indexing sleeve  104  moves down without taking the ramp sleeve  122  with it because opening  118  rather than ridge  116  is juxtaposed at lug  124  of the ramp sleeve. Collet heads  130  are trapped by surface  148  of indexing sleeve  104  to groove  132 . Snap ring  110  has moved closer to tapered ends  138  that have remained stationary with the rest of the ramp sleeve  122 . The reason for all this is that with the collet heads  130  trapped, the ramp sleeve  122  cannot move as the indexing sleeve  104  keeps coming down such that the snap ring  110  will be forced up ramps  138  as the ramp sleeve is held anchored by collet heads  130 . In effect the snap ring  110 , which had before acted as the travel stop when pressure in the tubing  78  is removed, is no longer the travel stop as it has been forced out of its groove  112  after clearing the ramps  138 . Pin  106  is in position  150  in the j-slot  108  as shown in  FIG. 3 . 
         [0024]    In  FIG. 8  the snap ring  110  has ridden up ramps  138  and out of groove  112 . Groove  134  on indexing sleeve  104  is now aligned with collet heads  130  such that those collet heads  130  are no longer locked to groove  132  to allow for tandem movement of the ramp sleeve  122  and the indexing sleeve  104  to move under the force of spring  100  with shoulder  150  on indexing mandrel  104  engaging the lug  124  on the ramp sleeve  122  for the downward tandem movement. Pin  106  is now in position  152  in the j-slot  108  shown in  FIG. 3 . 
         [0025]    In  FIG. 9  actuation of the downhole tool has occurred by extension of rod  68 . The collet heads  130  have landed in groove  131 . The ramp sleeve  122  has traveled a sufficient distance so that the ramps  138  clear the lower end  114  of the groove  112 . The spring  100  has reached a relaxed state as the pin  106  has reached location  154  in the j-slot  108  shown in  FIG. 3 . Bottom sub  66  can serve as a travel limiter if needed as surface  156  approaches it. 
         [0026]      FIG. 10  represents with a schematic arrow  158  a mechanical tool inserted into the tubing  78  to physically displace the rod  68  back up to location  152  shown in the j-slot  108  shown in  FIG. 3 . The snap ring  110  is back in groove  112  and against its lower end  114  so that it again can resist the force of spring  100  as the pressure cycling procedure can be restarted for another occasion of needed actuation. Pin  106  has remained in the straight j-slot groove  140  during this procedure. Opening  118  is still juxtaposed to lug  124  on the ramp sleeve but at the next pressure up cycle the indexing sleeve  104  will rotate as it rises to present ridge  116  to lug  124  as a result of pin  106  going up path  160  shown in  FIG. 3 . Note the collet fingers  126  have not moved during the mechanical reset of  FIG. 10  from the  FIG. 9  position. 
         [0027]    Those skilled in the art will appreciate that the  FIG. 2  embodiment and its movements represent a modular assembly that can be coupled to any mechanically operated tool to add a pressure actuation feature. The further advantage of the  FIG. 2  versus the  FIG. 1  embodiment is that the module  60  can be pressure actuated multiple times with a mechanical reset in between actuations coming from a tool run into the module  60  such as a shifting tool, for example. With the design to allow multiple actuations described above those skilled in the art will appreciate that the rod  68  need only to be raised a short distance vertically enough to get the snap ring  110  back into groove  112  as the pin  106  tracks straight up in slot  140  of the j-slot  108  shown in  FIG. 3 . 
         [0028]    Any number of pressure cycles can be designed into the tool before actuation limited only by the tool size that limits the ability to put more passages into the j-slot  108 . While long slots  140  are shown 6 pressure cycles apart, those skilled in the art will realize that with the use of a blocking lug there will be no actuation until the all pins  106  line up with the long slot  140  with no blocking lug in the way. It is also clear to see that the embodiment of  FIG. 1  is far simple while allowing but a single operation using pressure cycles. Spring  100  can be replaced with a charged chamber that is properly sealed. 
         [0029]    Operators who need a downhole tool such as an isolation valve in an application where mechanical operation is sufficient no longer need to buy assemblies that offer features they don&#39;t want and for a higher cost. On the other hand where the project requirements change before the start and it is decided that a pressure actuation feature is in fact needed, the modular design of the present invention allows a simple add on module that can be secured to the tool to provide this feature. Adding the module allows the option of hydraulic operation for at least one direction of actuation and still leaves open the ability to operate the valve in opposed directions between open and closed purely mechanically even with the module attached. 
         [0030]    While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the exemplified embodiments set forth herein but is to be limited only by the scope of the attached claims, including the full range of equivalency to which each element thereof is entitled.