Abstract:
Methods and apparatus for utilizing a downhole deployment valve (DDV) to isolate a pressure in a portion of a bore are disclosed. The DDV system can include fail safe features such as selectively extendable attenuation members for decreasing a falling object&#39;s impact, a normally open back-up valve member for actuation upon failure of a primary valve member, or a locking member to lock a valve member closed and enable disposal of a shock attenuating material on the valve member. Actuation of the DDV system can be electrically operated and can be self contained to operate automatically downhole without requiring control lines to the surface. Additionally, the actuation of the DDV can be based on a pressure supplied to an annulus.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/270,015, filed Oct. 11, 2002; is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/288,229, filed Nov. 5, 2002; and is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/783,982, filed Feb. 20, 2004, which is a continuation in part of U.S. patent application Ser. No. 10/677,135, filed Oct. 1, 2003, and U.S. patent application Ser. No. 10/676,376, filed Oct. 1, 2003, and which claims benefit of U.S. Provisional Patent Application Ser. No. 60/485,816, filed Jul. 9, 2003, all herein incorporated by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     Embodiments of the invention generally relate to methods and apparatus for use in oil and gas wellbores. More particularly, the invention relates to methods and apparatus for utilizing deployment valves in wellbores.  
         [0004]     2. Description of the Related Art  
         [0005]     Oil and gas wells are typically initially formed by drilling a borehole in the earth to some predetermined depth adjacent a hydrocarbon-bearing formation. After the borehole is drilled to a certain depth, steel tubing or casing is typically inserted in the borehole to form a wellbore, and an annular area between the tubing and the earth is filled with cement. The tubing strengthens the borehole, and the cement helps to isolate areas of the wellbore during hydrocarbon production. Some wells include a tie-back arrangement where an inner tubing string located concentrically within an upper section of outer casing connects to a lower string of casing to provide a fluid path to the surface. Thus, the tie back creates an annular area between the inner tubing string and the outer casing that can be sealed.  
         [0006]     Wells drilled in an “overbalanced” condition with the wellbore filled with fluid or mud preventing the inflow of hydrocarbons until the well is completed provide a safe way to operate since the overbalanced condition prevents blow outs and keeps the well controlled. Overbalanced wells may still include a blow out preventer in case of a pressure surge. Disadvantages of operating in the overbalanced condition include expense of the mud and damage to formations if the column of mud becomes so heavy that the mud enters the formations. Therefore, underbalanced or near underbalanced drilling may be employed to avoid problems of overbalanced drilling and encourage the inflow of hydrocarbons into the wellbore. In underbalanced drilling, any wellbore fluid such as nitrogen gas is at a pressure lower than the natural pressure of formation fluids. Since underbalanced well conditions can cause a blow out, underbalanced wells must be drilled through some type of pressure device such as a rotating drilling head at the surface of the well. The drilling head permits a tubular drill string to be rotated and lowered therethrough while retaining a pressure seal around the drill string.  
         [0007]     A downhole deployment valve (DDV) located within the casing may be used to temporarily isolate a formation pressure below the DDV such that a tool string may be quickly and safely tripped into a portion of the wellbore above the DDV that is temporarily relieved to atmospheric pressure. An example of a DDV is described in U.S. Pat. No. 6,209,663, which is incorporated by reference herein in its entirety. The DDV allows the tool string to be tripped into the wellbore at a faster rate than snubbing the tool string in under pressure. Since the pressure above the DDV is relieved, the tool string can trip into the wellbore without wellbore pressure acting to push the tool string out. Further, the DDV permits insertion of a tool string into the wellbore that cannot otherwise be inserted due to the shape, diameter and/or length of the tool string.  
         [0008]     Actuation systems for the DDV often require an expensive control line that may be difficult or impossible to land in a subsea wellhead. Alternatively, the drill string may mechanically activate the DDV. Hydraulic control lines require crush protection, present the potential for loss of hydraulic communication between the DDV and its surface control unit and can have entrapped air that prevents proper actuation. The prior actuation systems can be influenced by wellbore pressure fluxions or by friction from the drill string tripping in or out. Furthermore, the actuation system typically requires a physical tie to the surface where an operator that is subject to human error must be paid to monitor the control line pressures.  
         [0009]     An object accidentally dropped onto the DDV that is closed during tripping of the tool string presents a potential dangerous condition. The object may be a complete bottom hole assembly (BHA), a drill pipe, a tool, etc. that free falls through the wellbore from the location where the object was dropped until hitting the DDV. Thus, the object may damage the DDV due to the weight and speed of the object upon reaching the DDV, thereby permitting the stored energy of the pressure below the DDV to bypass the DDV and either eject the dropped object from the wellbore or create a dangerous pressure increase or blow out at the surface. A failsafe operation in the event of a dropped object may be required to account for a significant amount of energy due to the large energy that can be generated by, for example, a 25,000 pound BHA falling 10,000 feet.  
         [0010]     Increasing safety when utilizing the DDV permits an increase in the amount of formation pressure that operators can safely isolate below the DDV. Further, increased safety when utilizing the DDV may be necessary to comply with industry requirements or regulations.  
         [0011]     Therefore, there exists a need for improved methods and apparatus for utilizing a DDV.  
       SUMMARY OF THE INVENTION  
       [0012]     The invention generally relates to methods and apparatus for utilizing a downhole deployment valve (DDV) system to isolate a pressure in a portion of a bore. The DDV system can include fail safe features such as selectively extendable attenuation members for decreasing a falling object&#39;s impact, a normally open back-up valve member for actuation upon failure of a primary valve member, or a locking member to lock a valve member closed and enable disposal of a shock attenuating material on the valve member. Actuation of the DDV system can be electrically operated and can be self contained to operate automatically downhole without requiring control lines to the surface. Additionally, the actuation of the DDV can be based on a pressure supplied to an annulus. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.  
         [0014]      FIG. 1  is a partial section view of a downhole deployment valve (DDV) with an electrically operated actuation and sensor system self contained downhole that utilizes a rack and pinion arrangement for opening and closing the DDV.  
         [0015]      FIG. 2  is a section view of a DDV with an electrically operated actuation assembly that includes an axially stationary and rotatable nut to move an inner sleeve engaged therein for opening and closing the DDV.  
         [0016]      FIG. 3  is a section view of a DDV with an electrically operated actuation assembly that includes a worm gear connected to a motor for driving a gear hinge of a valve member for opening and closing the DDV.  
         [0017]      FIG. 4  is a section view of a DDV having an annular pressure operated actuation assembly showing the DDV in a closed position.  
         [0018]      FIG. 5  is a section view of the DDV and annular pressure operated actuation assembly in  FIG. 4  illustrating the DDV in an open position.  
         [0019]      FIG. 6  is a section view of a DDV having a primary valve member and a back-up valve member and shown in an open position.  
         [0020]      FIG. 7  is a section view of the DDV in  FIG. 6  shown in a normal closed position with only the primary valve member closed.  
         [0021]      FIG. 8  is a section view of the DDV in  FIG. 6  shown in a back-up closed position with the back-up valve member activated since the integrity of the primary valve member is compromised.  
         [0022]      FIG. 9  is a section view of a DDV with an axially moveable lower support sleeve in a backstop position for aiding in maintaining a valve member closed.  
         [0023]      FIG. 10  is a section view of the DDV in  FIG. 9  with the axially moveable lower support sleeve in a retracted position to permit movement of the valve member.  
         [0024]      FIG. 11  is a section view of a DDV in a closed position with attenuation members extended into a central bore of the DDV for absorbing impact from a dropped object.  
         [0025]      FIG. 12  is a section view of the DDV in  FIG. 11  shown in an open position with the attenuation members retracted from the central bore of the DDV for enabling passage therethrough.  
         [0026]      FIG. 13  is a cross-section view of an attenuation assembly for use with a DDV to absorb impact from a dropped object.  
         [0027]      FIG. 14  is a view of a DDV positioned in a bore and coupled to coordinating upper and lower bladder assemblies used to actuate the DDV.  
         [0028]      FIG. 15  is a section view of an annular pressure operated actuation assembly shown in a first position to actuate a DDV to a closed position.  
         [0029]      FIG. 16  is a section view of the annular pressure operated actuation assembly in  FIG. 15  shown in a second position to actuate a DDV to an open position. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0030]     The invention generally relates to methods and apparatus for utilizing a downhole deployment valve (DDV) in a wellbore. For some of the embodiments shown, the DDV may be any type of valve such as a flapper valve or ball valve. Additionally, any type of actuation mechanism may be used to operate the DDV for some of the embodiments shown.  
         [0031]      FIG. 1  illustrates a downhole deployment valve (DDV)  100  within a casing string  102  disposed in a wellbore. The casing string  102  extends from a surface of the wellbore where a wellhead  104  would typically be located along with some type of valve assembly  106  which controls the flow of fluid from the wellbore and is schematically shown. The DDV  100  includes an electrically operated actuation and sensor system  108  self contained downhole, a housing  110 , a flapper  112  having a hinge  114  at one end, and a valve seat  116  in an inner diameter of the housing  110  adjacent the flapper  112 . Arrangement of the flapper  112  allows it to close in an upward fashion wherein a biasing member (not shown) and pressure in a lower portion  118  of the wellbore act to keep the flapper  112  in a closed position, as shown in  FIG. 1 . Axially movement of an inner sleeve  120  across the flapper  112  pushes the flapper  112  to an open position when desired.  
         [0032]     The axial movement of the inner sleeve  120  can be accomplished by the actuation and sensor system  108 . The actuation and sensor system  108  includes an electric motor  122  that drives a pinion  124  engaged with a rack  126  coupled along a length of the inner sleeve  120 . Thus, rotation of the pinion  124  causes axial movement of the inner sleeve  120 . Depending on the direction of the axial movement, the inner sleeve  120  either pushes the flapper  112  to the open position or displaces away from the flapper  112  to permit the flapper  112  to move to the closed position. A power pack  128  located downhole can provide the necessary power to the motor  122  such that electric lines to the surface are not required. The power pack  128  can utilize batteries or be based on inductive charge.  
         [0033]     Additionally, the actuation and sensor system  108  includes a monitoring and control unit  130  with logic for controlling the actuation of the motor  122 . The monitoring and control unit  130  can be located downhole and powered by the power pack  128  such that no control lines to the surface are required. In operation, the monitoring and control unit  130  detects signals from sensors that indicate when operation of the DDV  100  should occur in order to appropriately control the motor  122 . For example, the monitoring and control unit  130  can receive signals from a drill string detection sensor  132  located uphole from the DDV  100 , a first pressure sensor  134  located uphole of the flapper  112  and a second pressure sensor  136  located downhole of the flapper  112 . The logic of the monitoring and control unit  130  only operates the motor  122  to move the inner sleeve  120  and thereby move the DDV  100  to the open position when a drill string  138  is detected and pressure across the flapper  112  is equalized. Until the sensors  132 ,  134 ,  136  indicate that these conditions have been met, the monitoring and control unit  130  does not actuate the motor  122  such that the DDV  100  remains in the closed position. Therefore, the actuation and sensor system  108  makes operation of the DDV  100  fully automatic while providing a safety interlock.  
         [0034]      FIG. 2  shows a DDV  200  with an alternative embodiment for an electrically operated actuation assembly that includes an axially stationary and rotatable nut  224  to move an inner sleeve  220  engaged therein. Threads  225  along an inside surface of the nut  224  mate with corresponding threads  221  along an outside length of the inner sleeve  220 . Thus, rotation of the nut  224  by an electric motor (not shown) causes the inner sleeve  220  to move axially in cooperation with a flapper  212  for moving the DDV between open and closed positions. Like all the electrical actuation assemblies described herein, this actuation assembly may be controlled via a conductive control line to the surface or an actuation and sensor system as described above.  
         [0035]      FIG. 3  illustrates a DDV  300  with another alternative embodiment for an electrically operated actuation assembly that includes a worm gear  324  connected to a motor  322  for driving a gear hinge  326  of a valve member, such as flapper  312 . Rotation of the worm gear  324  rotates the flapper  312  to move the DDV  300  between open and closed positions. The worm gear  324  can be used to further aid in maintaining the flapper  312  in the closed position since the worm gear  324  can be designed such that the gear hinge  326  cannot drive the worm gear  324 . Again, a control line  301  to the motor  322  may be coupled either to the surface or an actuation and sensor system located downhole.  
         [0036]      FIG. 4  shows a DDV  400  having an annular pressure operated actuation assembly  401  that is illustrated relatively enlarged to reveal operation thereof. A casing string  402  having the DDV  400  therein is disposed concentrically within an outer casing string  403  to form an annular area  404  therebetween. The annular pressure operated actuation assembly  401  may be used to control a downhole tool such as the DDV  400  that would otherwise require a hydraulic control line connected to the surface for actuation. Consequently, the DDV  400  can be a separate component such as a currently available DDV designed for actuation using hydraulic control lines. Alternatively, the DDV  400  can be integral with the annular pressure operated actuation assembly  401 .  
         [0037]     The annular pressure operated actuation assembly  401  includes a body  406  and a piston member  408  having a first end  410  disposed within an actuation cylinder  414  and a second end  411  separating an opening chamber  416  from a closing chamber  417 . Pressure within bore  405  enters the actuation cylinder  414  through port  418  and acts on a back side  420  of the first end  410  of the piston member  408 . However, pressure within the annulus  404  acts on a front side  421  of the first end  410  of the piston member  408  such that movement of the piston member  408  is based on these counter acting forces caused by the pressure differential. Therefore, pressure within the bore  405  is greater than pressure within the annulus  404  when the piston member  408  is in a first position, as shown in  FIG. 4 . In this first position, fluid is forced from the closing chamber  417  since the volume therein is at its minimum while the opening chamber  416  is able to receive fluid since the volume therein is at its maximum. The fluid forced from the closing chamber  417  acts on an inner sleeve  420  of the DDV  400  and displaces the inner sleeve  420  away from a flapper  412  to permit the flapper  412  to close.  
         [0038]      FIG. 5  illustrates the DDV  400  and the annular pressure operated actuation assembly  401  in  FIG. 4  with the DDV  400  in an open position. In operation, fluid pressure is increased in the annulus  404  until the pressure in the annulus  404  is greater than the pressure in the bore  405 . At this point, the piston member  408  moves to a second position and forces fluid from the opening chamber  416 . The fluid forced from the opening chamber  416  acts on the inner sleeve  420  of the DDV  400  and displaces the inner sleeve  420  across the flapper  412  causing the flapper  412  to open. In order to not require that pressure be maintained in the annulus  404  in order to hold the DDV  400  open, the sleeve  420  can have a locking mechanism to maintain the position of the DDV  400  such as described in U.S. Pat. No. 6,209,663, which is herein incorporated by reference.  
         [0039]     For some embodiments, the actuation cylinder  414  does not include the port  418  to the bore  405 . Rather, a pre-charge is established in the actuation cylinder  414  to counter act pressures in the annulus  404 . The pre-charge is selected based on any hydrostatic pressure in the annulus  404 .  
         [0040]      FIG. 6  shows a DDV  600  in an open position and having a primary valve member  612  and a back-up valve member  613 . In the embodiment shown, the primary and back-up valve members  612 ,  613  are flappers held open by an axially movable inner sleeve  620  that is displaced to interferingly prevent the valve members  612 ,  613  from closing.  
         [0041]      FIG. 7  illustrates the DDV  600  in  FIG. 6  with the inner sleeve  620  retracted to permit the primary valve member  612  to close and place the DDV  600  in a normal closed position. A stop  604  along an inside surface of a housing  610  of the DDV  600  contacts a shoulder  602  of the inner sleeve  620  that has an enlarged outside diameter. The stop  604  interferes and prevents further axially movement of the inner sleeve  620 . Thus, the inner sleeve  620  continues to interfere with the back-up valve member  613  and prevent the back-up valve member  613  from closing during normal operation of the DDV  600 . However, applying a predetermined additional force (e.g., increased hydraulic pressure for embodiments where the inner sleeve is hydraulically actuated) to the inner sleeve  620  overcomes the stop  604 , which can be made from a shearable or otherwise retractable member. With the back-up valve member  613  always open to permit passage therethrough during normal operation of the DDV  600 , a dropped object will not damage the back-up valve member  613  regardless of whether the DDV  600  is in the open position or the normal closed position.  
         [0042]      FIG. 8  shows the DDV  600  in  FIG. 6  in a back-up closed position after the predetermined additional force is applied to the inner sleeve  620  to enable continued axial displacement of the inner sleeve  620 . The additional movement of the inner sleeve  620  displaces the inner sleeve  620  away from the back-up valve member  613  enabling the back-up valve member  613  to close. While the integrity of the primary valve member  612  is compromised, the DDV  600  in the back-up closed position can maintain safe operation.  
         [0043]      FIG. 9  illustrates a DDV  900  with an axially moveable lower support sleeve  902  in a backstop position for aiding in maintaining a valve member such as flapper  912  closed when the DDV  900  is in a closed position. In the backstop position, an end of the support sleeve  902  contacts a perimeter of the flapper  912 . The support sleeve  902  can include a locking feature as discussed above that maintains the support sleeve  902  in the backstop position without requiring continual actuation. With the support sleeve  902  providing additional support for the flapper  912 , the flapper  912  is not limited by a biasing member and/or pressure in the bore below the flapper to ensure that the flapper stays closed. Thus, the flapper  912  can support additional weight such as from a shock attenuating material (e.g., sand, fluid, water, foam or polystyrene balls) disposed on the flapper  912  without permitting the shock attenuating material to leak thereacross.  
         [0044]      FIG. 10  shows the DDV  900  in  FIG. 9  with the axially moveable lower support sleeve  902  in a retracted position to permit movement of the flapper  912  as an inner sleeve  920  moves through the flapper  912  to place the DDV  900  in an open position. The movement of the support sleeve  902  can occur simultaneously or independently from the movement of the inner sleeve  920 . Additionally, any electrical or hydraulic actuation mechanism such as those described herein may be used to move the support sleeve  902 .  
         [0045]      FIG. 11  illustrates a DDV  1100  in a closed position with attenuation members  1108 ,  1109  extended into a central bore  1105  of the DDV  1100  for absorbing impact from a dropped object (not shown). In the extended position, the inside diameter of the bore  1105  at the attenuation members  1108 ,  1109  is less than the outside diameter of the dropped object. In general, the attenuation members  1108 ,  1109  are any member capable of decreasing an impact of the dropped object by increasing the amount of time that it takes for the dropped object to stop. By decreasing the impact, the dropped object can possibly be saved and the potential for catastrophic damage is reduced. The axial length of the bore  1105  that the attenuation members  1108 ,  1109  span is of sufficient length to absorb the impact of the dropped object to a point where the pressure integrity of a valve member  1112  is not compromised. Preferably, the attenuation members  1108 ,  1109  catch the dropped object prior to the dropped object reaching the valve member  1112  of the DDV  1100 .  
         [0046]     Examples of suitable attenuation members  1108 ,  1109  include axial ribs, inflated elements or flaps that deploy into the bore  1105 . The attenuation members  1108 ,  1109  can absorb kinetic energy from the dropped object by bending, breaking, collapsing or otherwise deforming upon impact. In operation, a first section of the attenuation members (e.g., attenuation members  1108 ) contact the dropped object without completely stopping the dropped object, and a subsequent section of the attenuation members (e.g., attenuation members  1109 ) thereafter further slow and preferably stop the dropped object.  
         [0047]     Any actuator may be used to move the attenuation members  1108 ,  1109  between extended and retracted positions. Further, either the same actuator used to move the attenuation members  1108 ,  1109  between the extended and retracted positions or an independent actuator may be used to actuate the DDV  1100 . As shown in  FIG. 11 , an inner sleeve  1120  used to open and close the valve member  1112  may be used to move the attenuation members  1108 ,  1109  to the extended position by alignment of windows  1121  in the inner sleeve  1120  with the attenuation members  1108 ,  1109 , which can be biased toward the extended position.  
         [0048]      FIG. 12  shows the DDV  1100  in  FIG. 11  in an open position with the attenuation members  1108 ,  1109  retracted from the central bore  1105  of the DDV  1100  for enabling passage therethrough. In the retracted position, the inner diameter of the bore  1105  at the attenuation members  1108 ,  1109  is sufficiently larger than the outer diameter of a tool string (not shown) such that the tool string can pass through the attenuation members  1108 ,  1109 .  
         [0049]      FIG. 13  illustrates an attenuation assembly  1301  for use with a DDV to absorb impact from a dropped object. The attenuation assembly  1301  includes attenuation members  1308  that extend into a bore  1305  of the attenuation assembly  1301  and span an axial length of the attenuation assembly  1301  similar to the attenuation members  1108 ,  1109  shown in  FIGS. 11 and 12 . In this embodiment, the attenuation members  1308  couple to a housing  1310  by hinges  1309  and are actuated between the extended and retracted positions by rotation of an inner sleeve  1320 .  
         [0050]      FIG. 14  illustrates a DDV  1400  positioned in a bore  1403  and coupled to an upper bladder assembly  1416  and a lower bladder assembly  1417  that are used cooperatively to actuate the DDV  1400  between open and closed positions. The upper bladder assembly  1416  responds to annular pressure indicated by arrows  1402  in order to supply pressurized fluid to the DDV  1400 . However, the lower bladder assembly  1417  responds to bore pressure in order to supply pressurized fluid to the DDV  1400 . The DDV  1400  actuates based on which one of the bladder assemblies  1416 ,  1417  is alternately supplying more fluid pressure to the DDV  1400  than the other bladder assembly as determined by the pressure differential between the bore and the annulus. Accordingly, the DDV  1400  may be similar in design to the DDV  400  shown in  FIG. 4 . For example, fluid pressure supplied from the upper bladder assembly  1416  through an upper hydraulic line  1418  opens the DDV  1400 , and fluid pressure supplied from the lower bladder assembly  1417  through a lower hydraulic line  1419  closes the DDV  1400 . For some embodiments, the actuation of the DDV  1400  may be reversed such that fluid pressures supplied from the upper and lower bladder assemblies  1416 ,  1417  respectively close and open the DDV  1400 . Furthermore, the bladder assemblies  1416 ,  1417  may be arranged in any position relative to one another and the DDV  1400 .  
         [0051]     The upper bladder assembly  1416  includes a bladder element  1408  disposed between first and second rings  1406 ,  1410  spaced from each other on a solid base pipe  1404 . An elastomer material may form the bladder element  1408 , which can optionally be biased against a predetermined force caused by the annular pressure  1402 . For some embodiments, the first ring  1406  slides along the base pipe  1404  to further enable compression and expansion of the bladder element  1408 . In operation, increasing the annular pressure  1402  to a predetermined level compresses the bladder element  1408  against the base pipe  1404  to force fluid contained by the bladder element  1408  to the DDV  1400 .  
         [0052]     The lower bladder assembly  1417  includes a bladder element  1426 , a biasing band  1424  that biases the bladder element  1426  against a predetermined force caused by the bore pressure, and an outer shroud  1422  that are all disposed between first and second rings  1420 ,  1430  spaced from each other on a perforated base pipe  1404 . The pressure in a bore  1434  of the bladder assembly  1417  acts on a surface of the bladder element  1426  due to apertures  1428  in the perforated base pipe that also aid in protecting the bladder element  1426  from damage as tools pass through the bore  1434 . In operation, increasing the pressure in the bore  1434  to a predetermined level compresses the bladder element  1426  against the outer shroud  1422  to force fluid contained by the bladder element  1426  to the DDV  1400 . The length of the bladder elements  1408 ,  1426  depends on the pressures that the bladder elements  1408 ,  1426  experience along with the amount of compression that can be achieved.  
         [0053]      FIG. 15  shows an annular pressure operated actuation assembly  1501  (illustrated schematically and relatively enlarged to reveal operation thereof) in a first position to actuate a DDV  1500  to a closed position. The actuation assembly  1501  includes a diaphragm  1502 , an input shaft  1504 , a j-sleeve  1506 , an index sleeve  1508 , and a valve member  1510  within a valve body  1511  for selectively directing flow through first and second check valves  1512 ,  1514  and selectively directing flow from a bore pressure port  1517  to first and second ports  1516 ,  1518  of the valve body  1511 . This selective directing of flow of pressurized fluid to and from the DDV  1500  coupled to the first and second ports  1516 ,  1518  of the actuation assembly  1501  controls actuation of the DDV  1500 . The actuation assembly  1501  may control various other types of valves such as a sliding sleeve valve or a rotating ball valve to regulate flow of pressurized fluid to the DDV  1500 . Axial position of the index sleeve  1508  within the actuation assembly  1501  determines the axial position of the valve member  1510 , which directs flow through the valve body  1511  by blocking and opening flow paths with first and second ball portions  1522 ,  1524  of the valve member  1510 .  
         [0054]     The j-sleeve  1506  includes a plurality of grooves around an inner circumference thereof that alternate between short and long. The grooves interact with corresponding profiles  1526  along an outer base of the index sleeve  1508 . Accordingly, the index sleeve  1508  is located in one of the short grooves of the j-sleeve  1506  while the actuating assembly  1501  is in the first position. While a lower biasing member  1520  biases the valve member  1510  upward, the lower biasing member  1520  does not overcome the force supplied by an upper biasing member  1528  urging the valve member  1510  downward. Thus, the upper biasing member  1528  maintains the ball portions  1522 ,  1524  against their respective seats due to the index sleeve  1508  being in the short groove of the j-sleeve  1506  such that the upper biasing member  1528  is not completely extended as occurs when the index sleeve  1508  is in the long grooves of the j-sleeve  1506 . In the first position of the actuation assembly  1501 , pressurized fluid from the bore  1530  passes through the second port  1518  to the DDV  1500  as fluid received at the first port  1516  from the DDV  1500  vents through check valve  1512  in order to close the DDV  1500 .  
         [0055]      FIG. 16  illustrates the actuation assembly  1501  shown in a second position to actuate the DDV  1500  to an open position. In operation, fluid pressure in the annulus  1532  is increased to operate the actuation assembly  1501 . Pressure in the annulus  1532  acts on the diaphragm  1502  to move the input shaft  1504  down. A bottom end of the input shaft  1504  defines teeth  1535  corresponding to mating teeth  1534  along an upper shoulder of the index sleeve  1508 . The teeth  1535  of the input shaft  1504  merely contact the mating teeth  1534  of the index sleeve  1508  without fully mating rotationally until the profiles  1526  of the index sleeve have disengaged from the grooves of the j-sleeve  1506  upon the input shaft  1504  axial displacing the index sleeve  1508  relative to the j-sleeve  1506 . Once the profiles  1526  on the index sleeve  1508  disengage from the j-sleeve  1506 , the teeth  1535  on the input shaft  1504  are allowed to fully engage the mating teeth  1534  of the index sleeve  1508  causing the index sleeve  1508  to rotate. The input shaft  1504  moves up when pressure is relieved against the diaphragm  1502 . The profiles  1526  of the index sleeve  1508  then contact the j-sleeve  1506  causing the index sleeve  1508  to rotate into an adjacent set of the grooves in the j-sleeve  1506 . Since the adjacent set of grooves in the j-sleeve  1506  are long, the raised axial location of the index sleeve  1508  enables the valve member  1510  that is biased upward to move upward and redirect flow through the valve body  1511 . Additionally, the rotation of the index sleeve  1508  causes the mating teeth  1534  of the index sleeve  1508  to disengage from the teeth  1535  of the input shaft  1504  such that the actuation assembly  1501  is reset to cycle again and place the actuation assembly  1501  back to the first position. In the second position of the actuation assembly  1501 , pressurized fluid from the bore  1530  passes through the first port  1516  while fluid received at the second port  1518  vents through check valve  1512  in order to open the DDV  1500 .  
         [0056]     A shock attenuating material such as sand, fluid, water, foam or polystyrene balls may be placed above the DDV in combination with any aspect of the invention. For example, placing a water or fluid column above the DDV cushions the impact of the dropped object.  
         [0057]     Any of the features, characteristics, alternatives or modifications described regarding a particular embodiment herein may also be applied, used, or incorporated with any other embodiment described herein. While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.