Abstract:
A sliding sleeve is provided that includes a housing, a spinner sleeve, an inner sleeve, a collet, an actuator, and an indexer. An object passing through the interior of the sliding sleeve is caught by the actuator forcing the indexer to move linearly downward. The linear downward movement causes the indexer to rotate one halfstep at which point the object is released. The indexer, biased towards the upward position, is returned to the upper position while at the same time is again rotated half a step. Once the pre-set number of steps is reached the indexer moves upward to support the collet. With the collet supported the next object passing through the interior of the sliding sleeve is retained by the collet which in turn forces the inner sleeve to move downward. With the inner sleeve moved to the down position a flow path is opened through the sleeve from the interior to the exterior of the sliding sleeve.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Patent Application No. 62/291,366 that was filed on Feb. 4, 2016. 
     
    
     BACKGROUND 
       [0002]    In the course of producing oil and gas wells, typically after the well is drilled, the well may be completed. One way to complete a well is to divide the well into several zones and then treat each zone individually. Treating each section of the well individually may be accomplished in several ways. 
         [0003]    One commonly used way of accessing the area to be treated is referred to as plug and perf. Generally, when plug and perf is used a perforating assembly is prepared on the surface. The perforating assembly typically consists of a plug on the lower end of the assembly, a setting tool just above the plug, and a perforating gun just above the setting tool. The assembly is then run into the wellbore to some point below the first zone that the operator desires to treat. The setting tool is then activated locking the plug into place and sealing the well below the plug against fluid flow from the surface or the well above the plug. The setting tool is then disconnected from the plug allowing the setting tool in the perforating gun to be moved to a point adjacent the first zone that the operator desires to treat. The perforating gun is then activated penetrating the casing to allow access to the first zone. The process is then repeated to allow access to each additional zone. One of the difficulties with the plug and perf method of accessing the zones is that is time intensive which in times of rig scarcity vastly increases the cost of the plug and perf method. 
         [0004]    Another commonly used method of accessing the area to be treated is to assemble a tubular assembly on the surface where the tubular assembly has a series of spaced apart sliding sleeves. Sliding sleeves are typically spaced so that at least one sliding sleeve will be adjacent to each zone. In some instances, annular packers may also be spaced apart along the tubular assembly in order to divide the wellbore into the desired number of zones. The tubular assembly is then run into the wellbore typically with the sliding sleeves in the closed position. In instances when annular packers are not used to divide the wellbore into the desired number of zones the tubular assembly may be cemented in place. 
         [0005]    Once the tubular assembly is in place in the well and has been cemented in place or the packers have been actuated each of the sliding sleeves are opened in turn. To open a sliding sleeve, an obturator, such as a ball, a dart, etc., is dropped into the wellbore from the surface and pumped through the tubular assembly. The obturator is pumped through the tubular assembly to the sliding sleeve where it lands on the seat of the sliding sleeve and forms a seal with the seat on the sliding sleeve to block all further fluid flow past the ball and the seat. As additional fluid is pumped into the well the differential pressure formed across the seat and ball provides sufficient force to move the sliding sleeve from its closed position to its open position. Fluid may then be pumped out of the tubular assembly and into the formation so that the formation may be treated. 
         [0006]    The use of sliding sleeves to access the well tends to avoid the time issue of the plug and perf method however the use of sliding sleeves tends to reduce the volume of fluid that may flow upward through the wellbore at any given time. The reduced volume of fluid that is able to flow through the wellbore is due to the varying sizes of the balls required to activate each individual sliding sleeve. Specifically, in order to individually activate a sliding sleeve each sliding sleeve requires its own ball size such that the smallest ball and consequently the smallest diameter seat is located at the lower end of the well and each subsequent ball, to activate the next higher sliding sleeve within the wellbore, is slightly larger than the ball used to activate the sliding sleeve below. Therefore, the amount of fluid that can flow through the lowest seat in the lowest sliding sleeve is reduced. 
       SUMMARY 
       [0007]    In an embodiment of the present invention a unique counting system is utilized allowing multiple balls to pass through the counting mechanism while activation of a sliding sleeve is delayed until the appropriate number of balls have passed through. By counting the number of balls passing through rather than using various sizes of balls as in a typical sliding sleeve arrangement, reductions in the inner diameter of the wellbore tubular are avoided. The counting sliding sleeve allows the wellbore tubular to remain relatively uniform in inner diameter avoiding any reduced flow past a particular sliding sleeve. The time costs of plug and perf are also avoided by utilizing a ball system so that the operator does not need to run in and out of the well to access each formation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  depicts a cutaway view of a counting sliding sleeve. 
           [0009]      FIG. 2  depicts an orthogonal view of the collet seat of the counting sliding sleeve. 
           [0010]      FIG. 3  depicts an orthogonal view of the spinner sleeve of the counting sliding sleeve. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]      FIG. 1  depicts a counting sliding sleeve  10 . The counting sliding sleeve  10  interacts with a ball or other object that is pumped down the wellbore from the surface. 
         [0012]    At the top of the counting sliding sleeve  10 , is a top sub  12 , a shear ring assembly  14 , and ports  16 . The shear ring assembly  14  could be a shear pin, a shear ring, snap ring, etc. 
         [0013]    A counting sliding sleeve  10  is limited to a maximum number of counts only in relation to the diameter of a particular tool. 
         [0014]    It can be seen that spinner sleeve  40  has a number of buttons  80  about the interior circumference of spinner sleeve  40 . While even a single button  80  would allow the spinner sleeve  40  to function, multiple buttons  80  are preferred. In the spinner sleeves  40  initial position each button  80  is supported, prevented from moving radially outward, by the outer housing  52  such that after a ball passes through the collet  22  it moves into the interior of the spinner sleeve  40  and interacts with buttons  80 . The buttons  80  in their supported position do not allow the ball to pass through. With the ball supported on buttons  80 , pressure may be applied from the surface against ball  80  and thereby to spinner sleeve  40  causing spinner sleeve  40  to move downward. As spinner sleeve  40  moves downward the spinner sleeve  40  is rotated one halfstep as described below. Additionally, as spinner sleeve  40  moves downward, buttons  80  move to a position relative to the outer housing  52  such that the buttons  80  are allowed to move radially outward into recess  82  within outer housing  52 . As the buttons move radially outward into recess  82  the ball is released allowing the ball to pass through the interior of spinner sleeve  40 . Once the ball has been released the downward force upon spinner sleeve  40  is removed allowing biasing device  50  to push the spinner sleeve  40  upwards. As spinner sleeve  40  moves upwards the torsional biasing device  60  as well as the interaction between pin  62  and slot  64 , force the spinner sleeve  40  to rotate a second halfstep. With the first halfstep and the second halfstep completed the spinner sleeve is back in its initial, albeit slightly rotated, position provided the spinner sleeve  40  has not reached the end of its count, the spinner sleeve  40  is now ready to accept the next ball that passes through the interior of the tubular. 
         [0015]    In the event that spinner sleeve  40  does reach the end of its count, where the count is the interaction between the slots  64  and pins  62 , the spinner sleeve  40  moves upwards an additional distance upward such that the upper end  84  of spinner sleeve  40  moves into recess  54 . With the upper end  84  of spinner sleeve  40  within recess  54  the distal ends  37  of the collet fingers  34  and  36  are now supported. The next properly sized obturating object such as a ball (not shown) that reaches the counting sliding sleeve  10  will land on the now supported distal ends  37  of the collet fingers such as  34  and  36  and form a seal with the inner collet elastomer element  36  allowing pressure to be applied against the ball from the surface. With pressure applied from the surface the shear device such as shear ring  14  is overcome allowing sleeve  56  to move downward within spinner sleeve  40  until the distal ends  37  of the collet fingers and the outer collet elastomer element  38  reach and seal against shoulder  42  within spinner sleeve  40 . Once the collet fingers and outer collet elastomer element  38  seat against shoulder  42  within spinner sleeve  40  both the spinner sleeve  40  and the sleeve  56  continue downward in response to pressure applied from the surface against the ball. As the sleeve  56  and spinner sleeve  40  are moved downward ports  16  are uncovered allowing fluid access from the interior of the spinner tool  10  through the housing  52 . An anti-reverse lock  44  such as spring-loaded C ring, a spring-loaded pin, or the depicted snap ring sits in a recess or slot  46 . The anti-reverse lock  44  is provided to hold the sleeve  56  open when sleeve  56  moves downward. As the snap ring  44  reaches recess  54  the snap ring will expand radially outward into recess  54  thereby preventing the interior sleeve  56  from re-closing which in turn would prevent fluid access from the interior of the spinner tool  10  through ports  16 . 
         [0016]    The distance between the seals  18  and  20  on either side of the ports  16  in order to isolate the ports  16  is minimized in order to decrease the overall length of the tool. 
         [0017]    The collet  22  flexes allowing the ball (not shown) to pass through. The seat is initially unsupported such that when the ball reaches the collet  22  the collet fingers, such as collet fingers  34  and  36  flex outwards so as to minimally impede the balls passage past the collet. The housing  52  has a recess  54  to allow the distal end  37  of the collet fingers, such as collet finger  34  and  36 , to expand radially outward thereby allowing a properly sized obturator to move past the distal end  37  of the collet  22 . 
         [0018]      FIG. 2  depicts the collet  22 . Typically when a collet goes through a number of expansions there is a potential for the elastomeric seat  30  and more specifically the elastomer  32  between any two fingers such as finger  34  and finger  36  to break or de-bond from one of the fingers  34  or  36 . In the current embodiment an inner collet elastomer element  36  is bonded to at least a portion of the inner face of the distal end  37  of collet  22  and an outer collet elastomer element  38  is bonded to the at least a portion of the outer face of the distal end  37  of collet  22 . 
         [0019]    Typically, the outer collet elastomer element  38  is constructed such that when collet  22  is forced downward into spinner sleeve  40  the outer collet elastomer element  38  will seat against shoulder  42  and in conjunction with the collet fingers distal and such as collet fingers  34  and  36 , inner collet elastomer element  36 , and the obturating object such as a ball (not shown) will form a seal to prevent fluid flow past collet  22 . 
         [0020]    In certain instances is been found advantageous to cut the elastomer  32  or more specifically the inner collet elastomer element  36  and the outer collet elastomer element  38  between each of the collet fingers such as fingers  34  and  36 . Additionally it has been found that cutting or forming the distal ends  37  of the collet fingers such as collet fingers  34  and  36  at both a radial angle and an axial angle so that when in obturating object attempts to force the collet fingers  34  and  36  radially outward, the force provided by the obturating object against the collet fingers tends to lock any elastomer between the collet fingers such as collet fingers  34  and  36  in place forming an enhanced seal. 
         [0021]    The collet  22  is provided with an elastomer on the inside, an elastomer on the outside, and the scarf cut collet fingers include an elastomer between the collet fingers. The scarf cut is located at the distal ends  37  of the collet fingers, such as collet fingers  34  and  36 , and are cut or formed at both a radial angle and an axial angle such that when the fingers are compressed radially outward elastomer between the fingers is compressed forming an enhanced seal. 
         [0022]      FIG. 3  more clearly depicts spinner sleeve  40  and slot  64 . The spinner sleeve  40  has a torsional biasing device such as torsional spring  60  apply torque to the spinner sleeve  40 . Pin  62  is formed such that pin  62  protrudes radially inward from sleeve  52  into a slot  64  in the outer surface of spinner sleeve  40 . It is envisioned that multiple pins will interact with slot  64  at various locations about the circumference of spinner sleeve  40  and housing  52 . Slot  64  steps circumferentially around spinner sleeve  40  such that when spinner sleeve  40  is forced downwards the interaction between pin  62  and slot  64  as well as the torsional force provided by the torsional biasing device  60  causes spinner sleeve  40  to rotate one half of a step. Then when the downward force acting on spinner sleeve  40  is removed the biasing device  50  acts on spinner sleeve  40  to move spinner sleeve  40  upwards back to spinner sleeves  40  initial position. As spinner sleeve  40  returns to its initial position the torsional biasing device such as torsional spring  60  in cooperation with the circumferential steps formed in slots  64  forces spinner sleeve  40  to rotate another one half of a step such that the downward and upward movement of spinner sleeve  40  completes a single step around the circumference of spinner sleeve  40 . When the desired number of steps of been completed, i.e. the last step, spinner sleeve  40  is allowed to move through slot  67  an additional distance upward such that the upper end  66  of spinner sleeve  40  passes over the distal ends  37  of collet  22  thereby supporting collet  22  and preventing the radial expansion of collet  22 . 
         [0023]    As shown in  FIG. 4 , spinner sleeve  40  is marked about it circumference by indicator  68 . In this case indicator  68  is shown to be marked within a recess  70  on the outer surface of spinner sleeve  40 . When viewed through port  74  in housing  52  shown in  FIG. 2  indicator  68  provides the operator with information as to how many cycles the spinner sleeve will require in order to lock the distal ends  37  of collet  22  in place thereby allowing sleeve  56  to move downward in order to provide fluid access from the interior of the sleeve  56  to the exterior of spinner tool  10  through ports  16 . Typically port  74  is blocked by a removable plug. 
         [0024]    It is envisioned that the tool or components thereof may be built from steel, aluminum, cast iron, composite, erodible material, dissolvable material, etc. 
         [0025]    While the embodiments are described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions and improvements are possible. 
         [0026]    Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter.