A device for controlling and isolating a tool in the form of an expansible sleeve for isolating areas in a well

Abstract

The present invention relates to a device for controlling and isolating a tool for isolating areas in a well which comprises: a main inlet conduit which communicates with the inside of said casing, and which is obturated by a first element able to form a barrier to a fluid circulating in said casing, while yielding beyond a first pressure, this conduit communicating, with two auxiliary conduits, the ends of which join up in order to form an outlet conduit, one of these auxiliary conduits, forming a first chamber, while, in the other one, a second element is provided forming a barrier, moveable between a first position and a second position wherein said first position, said second element forming a barrier and the wall of said second auxiliary conduit make between them a sealed annular chamber in which prevails a so-called <<isolation>> pressure, this chamber not communicating with the outside, notably with the well.

1 . A device for controlling and isolating a tool in the form of an expansible sleeve for treating a well or a duct, this tool being connected to a casing for supplying a pressurized fluid and is inserted between said casing and the wall of said well or of the duct, which comprises:
 a main inlet conduit which communicates with the inside of said casing, and which is obturated by a first element able to form a barrier to a fluid circulating in said casing, while yielding beyond a first predetermined pressure of said fluid,   this conduit communicating, downstream from said element forming a barrier, with two auxiliary conduits positioned in parallel, the ends of which join up in order to form an outlet conduit which opens inside the tool,   one of the auxiliary conduits, called<<first conduit>> forming, notably with said first element, a first chamber in which prevails an isolation pressure, while in the other one, called <<second conduit>>, a second element is provided, forming a barrier moveable between a first position in which it obturates this second conduit while clearing the communication between the first conduit and the outlet conduit, and a second position in which it prevents any communication between the auxiliary conduits and the outlet conduit, the passing from one position to the other being accomplished by increasing the fluid pressure to a second predetermined pressure greater than said first pressure,   
       wherein in said first position, said second element forming a barrier and the wall of said second auxiliary conduit make between them a sealed annular chamber wherein a so-called <<isolation>> pressure also prevails, this chamber not communicating with the outside, notably with the well. 
     
     
         2 . The device according to  claim 1 , wherein said second element comprises a piston constantly urged towards said second position. 
     
     
         3 . The device according to  claim 1 , wherein said second element includes a frangible part, such as a pin, positioned in the sealed chamber and which yields when the second predetermined pressure is attained. 
     
     
         4 . The device according to  claim 1 , wherein said isolation pressure is equal to atmospheric pressure or is slightly greater. 
     
     
         5 . The device according to  claim 1 , wherein said second element includes a metal <<nose>> which, in said second position, is in contact with the wall of the outlet conduit, also in metal, the assembly thereby forming a metal/metal seal. 
     
     
         6 . The device according to  claim 1 , wherein an anti-return valve is positioned inside the outlet conduit. 
     
     
         7 . The device according to  claim 6 , wherein the seal of said valve is ensured by a metal/metal contact. 
     
     
         8 . The device according to  claim 1 , wherein said expansible sleeve is in metal. 
     
     
         9 . The device according to  claim 3 , wherein it includes means for acoustically recording the breakage of the barrier-forming elements and means for recording the pressure in the annular space. 
     
     
         10 . The device according to  claim 9 , wherein said recording means may be queried remotely via RFID technology.