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FIELD 
       [0001]    This disclosure relates to down-hole production equipment for use in an oil well environment for selectively isolating fluid flow through a production packer or other down-hole tubular device. More particularly, this disclosure relates to a system and method utilizing a selectively operable valve. 
       BACKGROUND 
       [0002]    Various oil and gas production operations use ball valves. Often packers are used in conjunction with ball valves. The packer closes off the annulus between the tubing string and the well bore or casing. The ball valve can selectively close off the central flow passage of the tubing string such that flow is or is not allowed through the passageway depending on the setting of the ball valve. 
         [0003]    The ball valves of the prior art generally disclose use of a spherical ball-valve element, which in a closed valve position has seals, which seal or close off the central flow passageway of the tubing string so that the valve element will seal against pressure in one or both directions. Typically, rotation of the tubing string is used to operate the valve element to move it between open and closed positions. However, rotation is also used to operate other down-hole tools that can be used in conjunction with the ball valve; thus, requiring sequential rotative operations without a positive indication that the valve is fully closed. In addition, in highly deviated well bores, it can be difficult to achieve rotation to set, unset, open or close down-hole tools. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1  is a schematic view of a down-hole tool lowered into a well 
           [0005]      FIG. 2  is a cross-sectional schematic view of a ball-valve system in accordance with a first embodiment. 
           [0006]      FIG. 3  is an enlargement of actuator section of the ball-valve system illustrated in  FIG. 2 . 
           [0007]      FIGS. 4, 5 and 6  are isometric figures illustrating the movement of the actuating section of the ball-valve system of  FIG. 2 . 
           [0008]      FIG. 7  is an enlargement of the ball-valve section of the ball-valve system illustrated in  FIG. 2 . The ball-valve system is shown allowing flow through the central passageway. 
           [0009]      FIG. 8  is an enlargement of the balancing piston section of the ball-valve system illustrated in  FIG. 2 . 
           [0010]      FIG. 9  is an enlargement of a portion of the operating arm of the ball-valve section of the ball-valve system illustrated in  FIG. 2 . 
           [0011]      FIG. 10  illustrates the ball-valve section of  FIG. 7  with the ball valve moved to a position where flow in the central passageway is prevented. 
           [0012]      FIG. 11  illustrates the ball-valve section of  FIG. 7  with the ball valve locked in a position where flow in the central passageway is prevented. 
           [0013]      FIGS. 12, 13 and 14  are partial isometric and partial cross-sectional views illustrating the interaction of the actuator section and ball-valve sections. The isometric portion is shown without the outer sleeve. 
           [0014]      FIG. 15  is an isometric schematic view of a second embodiment of the ball-valve system. The ball-valve-system portion of the down-hole tool is shown without the outer sleeve. 
           [0015]      FIG. 16  is a cross-sectional schematic view of a ball-valve system in accordance with the second embodiment. 
           [0016]      FIG. 17  is an enlargement of the actuator section of the ball-valve system of  FIG. 16 . 
           [0017]      FIGS. 18, 19, 20 and 21  are isometric figures illustrating the movement of the actuating section of the ball-valve system of  FIG. 16 . The actuating section is shown without the outer sleeve. 
           [0018]      FIGS. 22, 23 and 24  are cross-sectional figures illustrating the interaction of the actuator section and ball-valve section of the ball-valve system of  FIG. 16 . 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Referring now to the drawings, wherein like reference numbers are used herein to designate like elements throughout the various views and various embodiments, which are illustrated and described. The figures are not necessarily drawn to scale, and in some instances the drawings have been exaggerated and/or simplified in places for illustrative purposes only. In the following description, the terms “upper,” “upward,” “up-hole,” “lower,” “downward,” “below,” “down-hole” and the like, as used herein, shall mean: in relation to the bottom or furthest extent of the surrounding wellbore even though the well or portions of it may be deviated or horizontal. The terms “inwardly” and “outwardly” are directions toward and away from, respectively, the geometric center of a referenced object. Where components of relatively well-known designs are employed, their structure and operation will not be described in detail. One of ordinary skill in the art will appreciate the many possible applications and variations of the present invention based on the following description. 
         [0020]    Referring now to  FIG. 1 , a down-hole tool  10  incorporating the invention is illustrated. Down-hole tool  10  comprises a valve system. As illustrated the valve system is a ball-valve system  12 . Additionally, the valve system may contain one or more other tools, such as packer  14  and tubing  16 . As illustrated, down-hole tool  10  is in a well bore  18  having a casing  20 . An annulus  22  is formed between down-hole tool  10  and casing  20 . A packer  14  prevents flow through the annulus  22  and anchors down-hole tool  10  in the wellbore, as is known in the art. The packer is shown in an unexpanded position in  FIG. 1 . 
         [0021]    Turning now to  FIG. 2 , a cross-sectional view of ball-valve system  12  is illustrated. Ball-valve system  12  comprises a tubular supporting mandrel  24 , which has an upper end  26  adapted to couple to a string of pipe or tubing, or to another down-hole tool. The lower end  28  of ball-valve system  12  is also adapted to couple to tubing or another down-hole tool, such as packer  14  illustrated in  FIG. 1 . Mandrel  24  defines a central flow passageway  30 , which lies upon the longitudinal axis of down-hole tool  10 . As used herein, longitudinal or axial refers to the long axis of mandrel  24  extending up-hole to down-hole. 
         [0022]    Ball-valve system  12  generally comprises an actuator section  50 , a ball-valve section  100  and a balancing piston section  150 .  FIGS. 3-6  illustrate one embodiment of the actuator system  50 . The actuator system  50  of  FIGS. 3-6  comprises a portion of mandrel  24  and an outer sleeve  51 . Outer sleeve  51  is positioned concentrically about mandrel  24  and may comprise one or more sleeve portions connected together. Mandrel  24  and outer sleeve  51  are in sliding relation so that an axial force on mandrel  24  will cause it to slide longitudinally in relation to outer sleeve  51 . Further, this sliding relation is resilient due to spring elements as further described below. Mandrel  24  has an uppermost position relative to sleeve  51  wherein spring  78  is fully expanded under the weight of mandrel  24 . Mandrel  24  has a lowermost position defined wherein spring  78  is compressed. The compression is limited by the movement of a lug in a straight leg channel, described below. 
         [0023]    Actuator section  50  further comprises a tubular member  54  and a ring  68 . As shown, tubular member  54  can be a portion of mandrel  24 . Tubular member  54  has a channel  58  on its outer surface  56 . Channel  58  comprises a straight leg section  60  and a circumferential section  62 . Straight leg section  60  extends substantially longitudinally along the surface of tubular member  54 , as shown in  FIG. 4 . Circumferential section  62  extends circumferentially about tubular member  54 . Circumferential section  62  has an upper or up-hole surface  64  and a lower or down-hole surface  66 . Each surface  64  and  66  has a saw tooth configuration. 
         [0024]    A ring  68  is positioned around tubular member  54 . Ring  68  is secured against longitudinal movement by coupling Coupling  52  and sleeve portion  53  but slidingly engages Coupling  52  and sleeve portion  53 . Additionally, ring  68  slidingly engages mandrel  24  and its tubular member  54 . Thus, ring  68  can rotate about the longitudinal axis of mandrel  24 . Ring  68  has a lug  70  extending inward into channel  58 . Lug  70  can be a fixed protuberance on the inner surface of ring  68  or can be a trapped ball bearing. 
         [0025]    Movement of mandrel  24  and its tubular member  54  is resiliently controlled by a spring  78  radially positioned between mandrel  24  and outer sleeve  51 . Further, spring  78  is longitudinally sandwiched between an outward extending shoulder  74  of mandrel  24  and an inward extending shoulder  72  of upper outer sleeve  51 . Coupling  52  forms inward extending shoulder  72 . Coupling  52  is part of outer sleeve  51 . Additionally, sleeve portion  53  of outer sleeve  51  is connected to Coupling  52  and ring  68  is longitudinally sandwiched between them. 
         [0026]    When mandrel  24  slides longitudinally down-hole relative to outer sleeve  51 , spring  78  is compressed, thus, biasing mandrel  24  and tubular member  54  in an up-hole direction. As can be seen from  FIG. 4 , when lug  70  is positioned in straight leg section  60  and no axial force is applied to mandrel  24 , lug  70  will be in the down-hole most position of straight leg section  60  due to the biasing effect of spring  78 . When sufficient axial force is applied to mandrel  24 , mandrel  24  will slide in relation to ring  68 ; thus, positioning lug  70  against upper surface  64 . Continued axial force, will cause ring  68  to rotate due to the saw tooth shape of upper surface  64 . The rotation places lug  70  in a crest  80  of upper surface  64 , as shown in  FIG. 5 . Releasing the axial force will cause mandrel  24  to slide longitudinally upward due to the biasing of spring  78 ; thus, lug  70  will contact lower surface  66  causing ring  68  to rotate due to the saw tooth shape of lower surface  66 . The rotation places lug  70  in a trough  82  of lower surface  66 , as shown in  FIG. 6 . 
         [0027]    Turning now to  FIG. 7 , the ball-valve section  100  of ball-valve system  12  is illustrated. Ball-valve section  100  includes sleeve portion  102  of outer sleeve  51 . Sleeve portion  102  is connected to sleeve portion  53  in fixed relation. Within sleeve portion  102  is a portion of mandrel  24 , balancing piston  152  and ball-valve element  106 . Ball-valve element  106  is positioned between mandrel  24  and balancing piston  152 . A first or top ball seat  108  is positioned between end  110  of mandrel  24  and ball-valve element  106  to provide sealing engagement and prevent fluid flow from central flow passageway  30  through the junction of end  110  and ball-valve element  106 . Similarly, a second or bottom ball seat  111  is positioned between end  155  of balancing piston  152  and ball-valve element  106  to provide sealing engagement and prevent fluid flow from central flow passageway  30  through the junction of end  155  and ball-valve element  106 . First and second ball seats  108  and  111  can be metal seats that provide a sealing engagement with ball-valve element  106 . 
         [0028]    Ball valve element  106  has spherical surface portions, which can be sealed against pressure in either direction in a closed condition of the valve, as further described below. Ball-valve element  106  is rotatable about a rotational axis transverse to the longitudinal axis of down-hole tool  10 . Ball-valve element  106  has a flow opening or passage  114  that extends there through. In a first rotative position or open position, flow opening  114  is aligned with central flow passageway  30 , thus allowing flow through central flow passageway  30 . In a second rotative position or closed position, flow opening  114  is transverse to central flow passageway  30 , thus preventing flow through central flow passageway  30 . 
         [0029]    Operating arm  116  controls the rotation of ball-valve element  106 . At one end, operating arm has a lug  118 . Ball-valve element  106  and operating arm  116  are attached by positioning lug  118  in an orifice  120 . A retainer  122  traps a second end of operating arm  116 . Operating arm  116  and retainer  122  are positioned between sleeve portion  102  and balancing piston  152 . Retainer  122  slidingly engages sleeve portion  102  and balancing piston  152 . The engagement is resilient and biased by spring  124  in an up-hole direction. Spring  124  is braced on the down-hole side by a shoulder  126  formed by ring portion  154  of balancing piston  152 . 
         [0030]    Thus, retainer  122  is resiliently restrained from down-hole movement by spring  124 . Additionally, retainer  122  is limited in up-hole movement by an offset or shoulder  130 , best seen from  FIG. 9 . 
         [0031]    As will be realized from an examination of  FIG. 7 , longitudinal movement of mandrel  24  in a down-hole direction will cause ball-valve element  106  to move down-hole. While operating arm  116  will also move down-hole as a result, its movement is resiliently restrained by spring  124 ; thus, it will create an upward force on one side of ball-valve element  106  by its connection at orifice  120 . The upward force causes ball-valve element  106  to rotate from an open position to a closed position. Similarly, from a closed position, upward movement of ball-valve element  106  will result in operating arm  116  rotating ball-valve element  106  from the close position to the open position. 
         [0032]    More than one operating arm can be attached to ball-valve element  106 ; thus, as illustrated, there is a second orifice  132  by which a second operating arm can be attached. 
         [0033]    Turning now to  FIG. 8 , balancing piston section  150  is illustrated. Balancing piston section  150  comprises sleeve portions  102  and  128  of outer sleeve  51 , balancing piston  152 , spring  156  and lower mandrel  158 . The lower portion  160  of balancing piston  152  is between the upper portion  162  of lower mandrel  158  and sleeve portion  102 . Upper portion  162  and sleeve portion  102  slidingly receive balancing piston  152  so that balancing piston  152  can move longitudinally up and down-hole. Balancing piston  152  resiliently slides and is upwardly biased by spring  156 . Spring  156  is sandwiched between upper portion  162  of lower mandrel  158  and sleeve portion  128 . At its lower end, spring  156  is braced by a shoulder  164  formed on lower mandrel  158 . 
         [0034]    Accordingly, balancing piston  152  can move downward when mandrel  24  and ball-valve element  106  move down-hole and can return upward when they return up-hole. Additionally, at all times balancing piston  152  is biased upward, and thus asserts pressure on ball-valve element  106  to maintain the seal of ball seats  108  and  111 , and to prevent pressure down-hole of the ball valve from rotating ball-valve element  106  to an unwanted position. Additionally, when pressure up-hole of the ball valve is greater than the pressure down-hole of the ball, fluid from up-hole can seep into ball-valve element  106  to prevent the ball valve from being forced into rotation by the up-hole pressure. 
         [0035]    With reference now to  FIGS. 7 and 10-14 , the operation of the down-hole tool will be further described. The ball valve element  106  being initially in the first rotative position shown in  FIGS. 7 and 12 , allows flow through central flow passage  30  defined up-hole of ball valve element  106  by mandrel  24  and down-hole of ball-valve element  106  by balancing piston  152  and lower mandrel  158 . In this position, mandrel  24  is in its upmost longitudinal position and lug  70  is at the bottom of straight leg section  60 . Because mandrel  24  is biased upwardly by spring  78 , ball-valve element  106  is locked in the first rotative state until a predetermine force is applied to mandrel  24  to overcome spring  78  sufficiently to move ball-valve element  106  to the second rotative state. 
         [0036]    Downward longitudinal force on mandrel  24  moves ball valve element  106  to its second rotative position. Typically, the downward longitudinal force or axial force will be exerted upon the mandrel by tubing string or tubing  16  attached to the upper end  26  of mandrel  24 . The axial force is applied by moving tubing  16  in a down-hole direction in the well bore. Tubing  16  then asserts the axial force on mandrel  24 . A packer  14  or another down-hole tool is attached to lower end  28  and is anchored in well bore  18  so as to prevent outer sleeve  51  from moving down-hole with mandrel  24  when the axial force is exerted. 
         [0037]    As shown in  FIGS. 10 and 13 , under this axial force mandrel  24  moves relative to sleeve  51  and moves downward until lug  70  comes in contact with upper surface  64  of circumferential section  62 . The downward movement of mandrel  24  transfers the downward force to ball-valve element  106 , thus moving it downward. Downward force asserted by ball-valve element  106  on operating arm  116  is at least partially countered by spring  124  so that operating arm  116  moves ball-valve element  106  to its second rotative position preventing flow through central flow passageway  30 . Downward force is also asserted by ball-valve element  106  on balancing piston  152 . Spring  156  allows balancing piston  152  to move downward with ball-valve element  106  while still maintaining upward pressure such that ball seats  108  and  111  maintain a fluid tight seal, hence prevention fluid in central flow passageway  30  from circumventing ball-valve element  106 . 
         [0038]    As explained above, contact of lug  70  with upper surface  64  causes ring  68  to rotate until lug  70  is in crest  80 . Subsequently, the longitudinal force is released causing mandrel  24  to move upward. However, because lug  70  now moves into contact with lower surface  66  of circumferential section  62 , mandrel  24  does not return to its uppermost position relative to sleeve  51 ; thus, ball-valve element  106  remains in the second rotative position. Contact of lug  70  with lower surface  66  causes ring  68  to rotate until lug  70  is in trough  82  locking ring  68  from further rotation without application of further downward longitudinal force. Thus, ball-valve element is now locked in the second rotative position as best seen in  FIGS. 11 and 14 . 
         [0039]    As will be noted from  FIGS. 11 and 14 , balancing piston  152  allows limited movement of ball-valve element  106  away from first ball seat  108  when up-hole pressure from the ball-valve element is greater than down-hole pressure from the ball-valve element. Thus, fluid from up-hole can enter flow opening  114 . This allows the pressure within ball-valve element  106  to equalize with the portion of central flow passageway  30  up-hole from ball-valve element  106 . This can prevent fluid pressure from up-hole forcing ball-valve element  106  out of its second rotative state. 
         [0040]    If the predetermined longitudinal force is again applied to mandrel  24 , then ring  68  again rotates due to interaction action of lug  70  and upper surface  64 . When the force is released, lug  70  will now contact a section of lower surface  66  that slopes down to straight leg section  60 . Accordingly, ring  68  will rotate due to interaction of lug  70  and lower surface  66  until lug  70  enters straight leg section  60 . At this point, spring  78  will be able to return mandrel  24  to its uppermost position relative to sleeve  51  allowing ball-valve element  106  to also move up and simultaneously rotate back to its first rotative position. It will be appreciated that the embodiments described herein move the ball-valve between a position allowing fluid flow and a position preventing fluid flow with only longitudinal movement (axial movement) of the mandrel and without rotational movement of the mandrel. 
         [0041]    Turning now to  FIGS. 15-24 , a second embodiment of the ball-valve system  12  is illustrated.  FIG. 15  illustrates an isometric view of the ball-valve system  12  and  FIG. 16  illustrates a cross-sectional view. Like the previous embodiment, ball-valve system  12  of  FIGS. 15 and 16  has an actuator section  200 , a ball-valve section  100  and a balancing piston section  150 . Ball-valve section  100  and balancing piston section  150  are substantially as described above. 
         [0042]    Turning now to  FIGS. 17-24 , the actuator system  200  is illustrated. The actuator system  200  comprises a portion of mandrel  24  and an outer sleeve  51 . Outer sleeve  51  is positioned concentrically about mandrel  24 . Mandrel  24  and outer sleeve  51  are in sliding relation so that an axial force on mandrel  24  will cause it to slide longitudinally in relation to outer sleeve  51 . Further, this sliding relation is resilient due to spring elements. 
         [0043]    Mandrel  24  terminates in a prod member  202 . Prod member  202  has a lower angled surface  203 , which contacts a ring  204  when mandrel  24  is in its uppermost position relative to sleeve  51 . Ring  204  is sandwiched between and is in sliding relation with a second mandrel  206 . Second mandrel  206  is in sliding relation with outer sleeve  51  and is in sealing contact with ball-valve element  106  by means of first ball seat  108 . Accordingly, downward force on mandrel  24  causes it to slide down-hole and transfers the force via prod member  202  to ring  204 . Ring  204  in response moves down-hole pushing against a shoulder  208  of second mandrel  206 , which in turn moves down-hole and pushes against ball-valve element  106 . As can be seen from  FIG. 17 , a spring  78  biases mandrel  24  towards an uppermost position relative to mandrel  51 , as previously described. 
         [0044]    Actuator section  200  further comprises a tubular member  210 , which is fixedly secured to outer sleeve  51 . As can best be seen from  FIG. 18-21 , tubular member  210  has a channel  212  formed from a straight leg section  214  and a circumferential section  216 . Straight leg section  214  extends substantially longitudinally along the surface of tubular member  210 . Circumferential section  216  extends circumferentially about tubular member  210 . In this embodiment, circumferential section  216  consists of only upper surface  218 . Upper surface  218  has a saw tooth configuration. 
         [0045]    Ring  204  can both longitudinally move and can rotate about the longitudinal axis of down-hole tool  10 . Ring  204  has an upper ring surface  218  that is saw tooth in shape, as best seen from  FIG. 19 . Ring  204  has a lug  220  extending upward along its outer surface to interact with channel  212 . Lug  220  has an upper angled surface  222 , which forms a part of upper ring surface  218 . 
         [0046]    When mandrel  24  slides longitudinally, down-hole relative to outer sleeve  51 , spring  78  is compressed; thus, mandrel  24  is biased in an up-hole direction. As can be seen from  FIG. 18 , when lug  220  is positioned in straight leg section  214  and no axial force is applied to mandrel  24 , lug  220  will be in the uppermost position of straight leg section  214  and upper angled surface  220  will be in contact with lower angled surface  203  of prod member  202  due to the biasing effect of spring  156 . 
         [0047]    When sufficient axial force is applied to mandrel  24 , mandrel  24  will slide longitudinally down-hole and prod member  202  will push ring  204 ; thus, moving lug  220  downward until it is adjacent to upper surface  218 , as shown in  FIG. 19 . Due to the angles on lower angled surface  203  and upper angled surface  222 , ring  204  will rotate. The rotation places upper angled  222  of lug  220  in contact with upper surface  218 . Prod member  202  comes in contact with a trough  228  in upper ring surface  226 . Upon release of the axial force, prod member  202  moves upwards allowing ring  204  to move upward. Because of the contact between the upper angled surface  222  of lug  220  and upper surface  218 , ring  204  is further rotated until upper angled surface  222  is in a crest  224  of upper surface  218 , as shown in  FIG. 20 . Thus, ring  204  is locked in position until another axial force of sufficient magnitude is applied to mandrel  24 . When such an axial force is applied, prod member  202  will come into contact with upper ring surface  226  and push ring  204  downward until lug  220  is free from crest  224 , as shown in  FIG. 21 . Ring  204  will then rotate due to the interaction of lower angled surface  203  of prod member  202  with the saw tooth surface of upper ring surface  226 . The rotation repositions lug  220  to a portion of upper surface  218  that is angled toward straight leg section  214 . When the axial force is released, lug  220  will be directed to enter straight leg section  214  by the interaction of upper surface  222  of lug  220  with upper surface  218 . 
         [0048]    The operation of the ball-valve element can be seen from  FIGS. 22 to 24 . Its operation is substantially as described above for the first embodiment, except that second mandrel  206  is in contact with ball-valve element  106  instead of mandrel  24 . 
         [0049]    As will be realized from the above disclosure, the disclosed ball-valve system provides for opening and closing the ball valve with only up and down movement of the mandrel and of the tubing connected to the mandrel&#39;s up-hole end. By eliminating the rotation of the tubing, the ball-valve system can provide a better and easier method to open and close a ball valve in a highly deviated well bore than provided by the use of ball valves relying on rotational movement of the tubing string to move between open and closed positions. 
         [0050]    In accordance with the above disclosure, various embodiments are now further described. In a first embodiment, a ball-valve system for use in a well casing is provided. The ball-valve system comprises a mandrel, a ball valve and an actuator. The mandrel defines a flow passageway extending longitudinally along a central axis of the mandrel. The ball valve is disposed within the mandrel. The ball valve includes a generally spherically shaped ball-valve element with a flow opening. The ball-valve element has a first rotative position in which the flow opening is aligned with the flow passageway thus allowing flow through the flow passage, and a second rotative position in which the flow opening is transverse to the flow passageway thus preventing flow through the flow passageway. The actuator comprises a tubular member and a ring. The ring engages the tubular member in a sliding relation relationship such that the tubular member and ring have an actuating movement. The actuating movement is a predetermined amount of relative longitudinal movement between the tubular member and the ring sufficient to move the ball-valve element between the first rotative position and the second rotative position. The actuating movement results in relative rotational movement of the tubular member and the ring. The relative rotational movement moves the ball-valve system between a first state in which the ball-valve element is locked in the first rotative position and a second state in which the ball-valve element is locked in the second rotative position. Generally, the actuator moves the ball-valve element between the first rotational position and second rotational position without rotational movement of the mandrel. 
         [0051]    In another embodiment, the ring can have a lug that travels in a channel of the tubular member. The channel comprises a straight longitudinal section and a circumferential section. The application and release of axial force moves the lug between the straight leg section and the circumferential section. The circumferential section can have an up-hole surface and a down-hole surface. In this embodiment, when the lug is in the straight longitudinal section, application of axial force on the tubular member causes the actuation movement, which places the lug in contact with the up-hole surface. This contact results in the relative rotational movement such that release of the axial force places the lug in contact with the down-hole surface. The contact with the down-hole surface locks the ball-valve element into the second rotative position. When the lug is in contact with the down-hole surface, application of axial force on the tubular member causes the actuation movement, which places the lug in contact with the up-hole surface. Contact with the up-hole surface results in the relative rotational movement such that release of the axial force places the lug into the straight longitudinal section such that the ball-valve element is locked into the first rotative position. The tubular member can form part of the mandrel and the application of axial force can be on the mandrel. 
         [0052]    In a further embodiment, the circumferential section has an up-hole surface. The ring has an angled upper surface and further comprises a prod member with an angled lower surface. In this embodiment, when the lug is in the straight longitudinal section, application of axial force on the prod member causes the lower angled surface of the prod member to interact with a portion of the upper angled surface of the ring on the lug. This interaction causes the actuation movement and the relative rotational movement such that the lug is placed into contact with the up-hole surface of the circumferential section to lock the ball-valve element in the second rotative position. When the lug is in contact with the up-hole surface, application of axial force on the prod member causes the lower angled surface of the prod member to interact with the upper angled surface of the ring. The interaction with the upper angled surface causes the actuation movement and relative rotational movement such that the lug is moved from contact with the up-hole angled surface into the straight longitudinal section to lock the ball-valve element in the first rotative position. The prod member can be part of the mandrel and the application of axial force can be on the mandrel. 
         [0053]    Additionally, the ball valve system of the above embodiments can further comprise a first spring disposed around the mandrel such that the first spring biases the relative longitudinal movement of the ring and the tubular member such that the lug is biased in an up-hole direction. 
         [0054]    The ball valve systems of the above embodiments can further comprise a balancing piston positioned down-hole of the ball valve. The balancing piston resiliently provides pressure to the ball-valve element to counteract fluid pressure in the flow passageway down-hole from the ball-valve element to thus prevent the fluid pressure from moving the ball-valve element from the second rotative position. 
         [0055]    The ball-valve system of the above embodiment can also comprise an operating arm slidingly engaging the balancing piston and an outer sleeve. The operating arm and ball-valve element are attached so that the operating arm resiliently moves the ball-valve element between the first rotative position and the second rotative position in response to the relative axial movement of the ring and tubular member. Further, the operating arm can have a lug and be attached to the ball-valve element by positioning the lug in an orifice in the ball-valve element. 
         [0056]    In addition, in the above embodiments the ball-valve element has an interior chamber such that, in the second rotative position, the interior chamber can be in fluid flow communication to a portion of the flow passageway up-hole from the ball valve when an up-hole pressure in the flow passageway above the ball valve exceeds a down-hole pressure in the flow passageway below the ball valve. 
         [0057]    In a further embodiment, a method of operating down-hole tool having a ball valve in a well bore is provided. The method comprises: 
         [0058]    introducing the down-hole tool into the well bore; 
         [0059]    moving a ring and a tubular member longitudinally relative to each other, wherein the ring and the tubular member are in sliding relationship to each other; 
         [0060]    moving the ball valve between a first rotative and a second rotational position in reaction to the longitudinal movement of the ring and tubular member, wherein the first rotative position allows flow through a flow passageway of the down-hole tool and the second rotative position prevents flow through the flow passageway; and 
         [0061]    moving the ring and the sleeve rotationally relative to each other, wherein the relative rotational movement of the tubular member and the ring moves the down-hole tool between a first state in which the ball valve is not locked in the second rotative position and a second state in which the ball valve is locked in the second rotative position. 
         [0062]    In some embodiments, the ring has a lug that travels in a channel of the tubular member. In these embodiments, the method further comprises applying axial force to cause the relative longitudinal movement and the relative rotational movement such that the lug is moved between a straight leg section of the channel and a circumferential section of the channel. 
         [0063]    In a portion of the embodiments using the lug and channel, the method further comprises: 
         [0064]    applying a first axial force so as to cause the relative longitudinal movement such that the lug is moved along a straight leg section of the channel and placed in contact with an up-hole surface of a circumferential section of the channel such that the contact with the up-hole surface results in the relative rotational movement, wherein the relative longitudinal movement moves the ball-valve element from the first rotative position to the second rotative position; 
         [0065]    releasing the first axial force such that the lug comes into contact with a down-hole surface of the circumferential section such that the ball-valve element is locked into the second rotative position; 
         [0066]    applying a second axial force so as to cause the relative longitudinal movement such that the lug is moved from contact with the down-hole surface and placed in contact with an up-hole surface such that the contact with the up-hole surface results in the relative rotational movement; and 
         [0067]    releasing the second axial force such that the lug enters the straight leg section and the ball-valve element is moved into the second rotative position. 
         [0068]    In another portion of the embodiments using the lug and channel, the circumferential section has an up-hole surface, the ring has an angled surface with a portion of the angled upper surface being on the lug, and the method further comprises: 
         [0069]    applying a first axial force on the prod member such that an angled surface of the prod member to interact with the portion of the angled surface of the ring so as to cause the relative longitudinal movement such that a lug on the ring travels in a straight leg channel on the tubular member, wherein the relative longitudinal movement moves the ball valve from the first rotative position to the second rotative position, and when the portion of the angled surface on the lug is aligned with an angled surface on the tubular member, the angled surface of the prod and the angled surface of the ring cause relative rotational movement placing the portion of the angled surface on the ring in contact with the angled surface of the tubular member; 
         [0070]    releasing the first axial force such that the lug is in locked contact with the angled surface of the tubular member thus locking the ball valve into the second rotative position; 
         [0071]    applying a second axial force on the prod member such that the angled surface of the prod member interacts with the angled surface of the ring so as to disengage the lug from locked contact with the angled surface of the tubular member so as to cause the relative rotational movement and align the lug with the straight leg channel; and 
         [0072]    releasing the second axial force on the prod member such that the lug travels into the straight line channel with the ring and tubular member undergoing the relative longitudinal movement, which moves the ball valve from the second rotative position to the first rotative position. 
         [0073]    Further embodiments of the method can comprise resiliently providing pressure, typically from one or more springs, to the ball valve to counteract fluid pressure in the flow passageway down-hole from the ball valve. Thus, this counteracting pressure prevents the ball valve from moving out of the second rotative position due to the down-hole fluid pressure. Also, the ball valve can resiliently move between the first rotative position and the second rotative position in response to the relative axial movement of the ring and tubular member by an operating arm attached to the ball valve. Also, the operating arm can have a lug, which is attached to the ball valve by positioning the lug in an orifice in the ball valve. In addition, in the above embodiments the ball-valve element can have a flow opening such that, in the first rotative position, the interior flow opening can be in fluid flow communication to a portion of the flow passageway up-hole from the ball valve when an up-hole pressure in the portion of flow passageway up-hole from the ball valve exceeds a down-hole pressure in a portion of the flow passageway down-hole from the ball valve. 
         [0074]    Other embodiments will be apparent to those skilled in the art from a consideration of this specification or practice of the embodiments disclosed herein. Thus, the foregoing specification is considered merely exemplary with the true scope thereof being defined by the following claims.

Summary:
An apparatus and method relating to down-hole production equipment for use in an oil well environment is provided. The apparatus and method are for selectively isolating fluid flow through a production packer or other down-hole tubular device. The apparatus and method use a ball valve, which is moved from an open position to a closed position by lateral or axial movement of the tubing string as opposed to by rotating the tubing string.