Abstract:
A system including a plurality of differential pressure actuated tools; a seat receptive to a plug; a first conduit fluidly communicating tubing pressure upstream of the seat to one end of each of the plurality of tools; and a second conduit fluidly communicating tubing pressure downstream of the seat to an opposite end of each of the plurality of tools and method.

Description:
BACKGROUND 
     Fracturing and other pressure based operations that occur at intervals along the length of a borehole often rely upon plugs (balls, darts, etc.) that are dropped or pumped to seats installed within the borehole. Upon landing at individual ones of such seats, pressure may be applied to actuate a tool or fracture a formation location. Because of a limited number of plug diameters that are practically possible, such systems are limited in the number of pressure events that can be created. 
     While the art has been using such systems for years and coping well with the limitations thereof, an alternative that would increase the number of events that could be created would be welcomed by the art. 
     SUMMARY 
     A system including a plurality of differential pressure actuated tools; a seat receptive to a plug; a first conduit fluidly communicating tubing pressure upstream of the seat to one end of each of the plurality of tools; and a second conduit fluidly communicating tubing pressure downstream of the seat to an opposite end of each of the plurality of tools. 
     A method for actuating a plurality of tools in a downhole environment including deploying a plug into a borehole including a plurality of differential pressure actuated tools; a seat receptive to a plug; a first conduit fluidly communicating tubing pressure upstream of the seat to one end of each of the plurality of tools; and a second conduit fluidly communicating tubing pressure downstream of the seat to an opposite end of each of the plurality of tools; landing the plug in the seat; creating a differential pressure across each of the plurality of tools; and actuating the plurality of tools with the differential pressure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring now to the drawings wherein like elements are numbered alike in the Figures: 
         FIG. 1  is a schematic illustration of a frac sleeve system in a pre actuation condition; 
         FIG. 2  is a schematic view of the same system in the actuated position. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a system  10  having more than one actuable tool  12  is illustrated. In the illustrations herein only two tools  12  are illustrated but it is to be appreciated that any plurality of tools  12  may be employed in the system. The overall concept of the system and method is the facilitation of an ability to actuate a plurality of tools based upon pressure applied from a remote location pursuant to a single plug being landed. The prior art, as noted above only actuates one tool per plug while the invention actuates any plurality. 
     As illustrated simply for ease of discussion, the tools  12  are sliding sleeves that include piston chambers  14  that are ported to the ID  16  of a string  18  at both an uphole end  20  and a downhole end  22  by conduits  24  and  26 , respectively. The conduits  24  and  26  may actually comprise control line run from the ends of the piston chambers  14  or may be simply fluid pathways through the tools. It is unimportant to the operation of the system how the fluid within the piston chamber is communicated to the ID upstream and downstream of the seat  28  but rather only that it is so communicated for that is the configuration that allows a differential pressure to be provided to a plurality of tools simultaneously. It is to be appreciated that both, or all in the case of more tools  12 , of the conduits  26  fluidly connect with the ID  16  downstream of a seat  28  while both, or all in the case of more tools  12 , of the conduits  24  fluidly connect to the ID  16  upstream of the seat  28 . The seat, with an accompanying plug  32  (see  FIG. 2 ), then provides for the differential pressure noted above that is generatable across both (or all) of tools  12  at the same time. The tools  12  are actuated simultaneously by pressuring up on the string  18  after the seating of the single plug  32  (see  FIG. 2 ). 
     It is also to be noted that it is not important where the conduits  24  and  26  end up connecting to the ID other than that conduits  24  must connect at one of upstream and downstream of the seat  28  and conduits  26  must connect at the other of upstream or downstream of the seat  28 , or in other words across the seat  28 , so that differential pressure can be generated. Where precisely they connect after that consideration is met is a matter of manufacturing convenience and material cost. Further, although in the example both of the tools  12  are “actuated” at the same time that does not necessarily mean that they must both move at the same rate to open. In some particular applications, one or more could be delayed if desired but the actuation pressure, which is a differential pressure across the seat  28 , and hence across pistons  34  in each chamber  14 , occurs simultaneously. 
     It is to be appreciated that the system illustrated in  FIGS. 1 and 2  can be stacked. This may be effected schematically simply by copying  FIG. 1  and pasting the duplicate longitudinally adjacent the first illustration. Each system then would have a plurality of tools  12 , a seat  28 , a set of conduits  24  fluidly connected to the string  18  on one side of the seat  28  and a set of conduits  26  fluidly connected to the string  18  on the other side of the seat  28 . 
     In a borehole configured with the system as disclosed, one or more of the systems  10  may be employed and in some embodiments a large number of the systems are employed. The number of tools  12  actuated by each plug  32  is not limited and the number of systems  10  is limited only by the number of configurations, such as plugs, that can produce a location across which differential pressure may be generated. 
     With respect to other pluralities of tools that are uphole of the plurality of tools shown in  FIGS. 1 and 2 , these will not be actuated by the pressure in the string  18  that is intended to actuate the plurality of tools  12  that are shown. This is because if there is no plug  32  in a seat that is associated with a particular plurality of tools  12 , there can be no pressure differential developed across the pistons  34 . Rather, pressurization of the string  18  without a plug  32  in a seat  28  that is associated with a particular plurality of tools  12  is applied to both sides of the piston chambers  14 , whereby the piston  34  in each will not move. A Seat  28  considered “associated” with a particular plurality of tools  12  is the seat  28  that is located between conduits  24  and  26  for a particular plurality of tools  12 . 
     Following tool actuation, pressure may also be used to, for example, fracture the formation through the tools, which may be, for example, valves such as open sliding sleeves, for example. Since other tools are experiencing balanced pressure, they and the formation at those tools is unaffected. Uphole of the particular system, the tools are unactuated and thence pressure is irrelevant and downhole of the particular system, pressure is hydrostatic alone due to the seated plug  32  at the particular system. It will be appreciated that seals  40  are positioned outside of string  18  to isolate individual zones. 
     Finally it is to be understood while one or more embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.