Abstract:
A pressure actuation enabling method includes plugging a passage that fluidically connects an inside with an outside of a tubular with a plug, building differential pressure across the plug, actuating an actuator with the differential pressure and removing the plug.

Description:
BACKGROUND 
     It is common in tubular systems to actuate an actuator using pressure. Doing so often requires plugging a passageway so that pressure can be built thereagainst. In cases wherein it is desirable to flow through the passageway after having built pressure against a plug engaged therewith the plug must be removed. Methods such as drilling or milling to remove a runnable plug work well for some applications. However, the time to run the drilling/milling equipment and perform the machining operation can be costly in lost production in the case where the tubular system is employed to recover hydrocarbons from an earth formation, for example. The art is therefore always interested in methods of allowing actuation without the aforementioned drawback. 
     BRIEF DESCRIPTION 
     Disclosed herein is a pressure actuation enabling method which includes plugging a passage that fluidically connects an inside with an outside of a tubular with a plug, building differential pressure across the plug, actuating an actuator with the differential pressure and removing the plug. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
         FIG. 1  depicts a partially transparent perspective view of a tubular arrangement configured to enable pressure actuation of an actuator; and 
         FIG. 2  depicts a partial cross sectional side view of an embodiment of a tubular arrangement disclosed herein. 
     
    
    
     DETAILED DESCRIPTION 
     A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
     Referring to  FIG. 1  a tubular arrangement configured to enable pressure actuation of an actuator is illustrated at  10 . The tubular arrangement  10  includes a base pipe  14  with perforations  18  through a wall  22  thereof and a sleeve  26  positioned radially of the base pipe  14  defining a passageway  30  in the annular space  34  therebetween. Fluidic communication is established between an inside  42  and an outside  46  through at least the annular space  34  and the perforations  18 . Additional flow channels, such as a screen  48  and an equalizer  74 , as shown in this embodiment, may also be included in the passageway  30 . The sleeve  26  is sealingly attached to the base pipe  14  at an end  35 . A plug  38  occludes the passageway  30  thereby preventing fluidic communication between the inside  42  and the outside  46  of the tubular arrangement  10 . The plug  38  is configured to support differential pressure between the inside  42  and the outside  46 . The differential pressure may be sufficient to actuate an actuator (item  58  of  FIG. 2 ). For example, the differential pressure could inflate a bladder of an inflatable packer or move a piston  62  ( FIG. 2 ), such as the packer and the piston disclosed in U.S. Pat. No. 7,621,322 to Arnold et al. incorporated by reference herein in its entirety. 
     The plug  38  is also configured to dissolve after being exposed to an environment, after which fluid communication between the inside  42  and the outside  46  is established via the passageway  30 . Such fluid communication prevents further building pressure differential between the inside  42  and the outside  46 . The plug  38  may be made of a high strength controlled electrolytic metallic material that is degradable/dissolvable in environments that include one or more of brine, acid, and aqueous fluid. For example, a variety of suitable materials and their methods of manufacture are described in United States Patent Publication No. 2011/0135953 (Xu et al.), which is hereby incorporated by reference in its entirety. Exposing the plug  38  to the degradable environment can be controlled in different ways. For example, fluid containing the aforementioned brine, acid or aqueous fluid can be introduced via pumping through the base pipe  14  and the perforations  18  to the plug  38 . 
     Referring to  FIG. 2 , alternately, the brine, acid or aqueous fluid  50  can be stored near the plug  38  in a chamber  54 , for example, and then allowed to access the plug  38  after actuation of an actuator  58 . The actuator  58  illustrated in this embodiment includes the piston  62  sealably engaged with both the tubulars  14  and  26  by seals  64  thereby defining the chamber  54 . A releasable member  66 , illustrated herein as a shear screw, fixes the piston  62  relative to the tubulars  14 ,  26  until pressure acting on the piston  62  is sufficient to release the releasable member  66 . Air or other compressible fluid stored in the chamber  54  with the brine, acid or aqueous fluid  50  prior to release of the releasable member  66  can facilitate generating longitudinal force on the piston  62  in response to differential pressure across the piston  62 . Upon release of the releasable member  66 , the piston  62  moves toward the chamber  54  (rightward in the Figure) until the seal  64  crosses a channel  70  in the base pipe  14  (note the channel  70  could just as well be formed in the sleeve  26 ) thereby allowing the fluid  50  to flow through the channel  70  by the seal  64  and out of the chamber  54 . Once the brine, acid or aqueous fluid  50  is out of the chamber  54  it can make contact with the plug  38 , thereby initiating dissolution thereof. The foregoing results in delay of initiation of dissolution of the plug  38  until after the actuation of the actuator  58  has taken place. It should be noted that additional actuation of actuators other than the actuator  58  can also be performed via differential pressure built against the plug  38 . By causing other such actuations at pressures lower than that needed to release the releasable member  66 , any practical number of actuations are possible prior to removal of the plug  38 . 
     In yet another alternate embodiment, the plug  38  can be exposed to a degradable environment that occurs in response to positioning of the tubular arrangement  10  within a given environment. For example, in a downhole hydrocarbon recover or carbon dioxide sequestration application, exposure of the plug  38  can be initiated by simply positioning the tubular arrangement  10  downhole within an anticipated environment. In such an embodiment, degradation of the plug  38  can begin upon initial exposure to fluid, temperatures and pressures, for example, of the downhole environment that reach the plug  38  after flowing from the outside  46  through the screen  48  the equalizer  74  and the annular space  34  to reach the plug  38 . In this embodiment the plug  38  can be configured so that a selected amount of time passes after exposure to the degrading environment has begun to allow the differential pressure to form and the actuation to take place before the plug  38  degrades enough to prevent maintaining the differential pressure. The equalizer  74 , shown positioned within the annular space  34 , can permit additional control of fluid flow between the outside  46  and the inside  42  after the plug  38  has been removed. 
     While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.