Valve assembly

Abstract

A system that is usable with a well includes a string and valve assemblies that are disposed on the string. The valve assembly includes at least one control port and at least one radial fluid communication port. The valve assembly is adapted to serially receive an untethered object deployed in the string such that receipt of the object by a valve assembly of the plurality of valve assemblies creates a fluid obstruction to cause the valve assembly to expose the at least one control port of the valve assembly; serially release the untethered object; and jointly respond to pressurization of the string to open the radial fluid communication ports.

What is claimed is: 
     
         1 . A method usable with a well, comprising:
 deploying an untethered object in a string, the string comprising valve assemblies and each of the valve assemblies comprising at least one control port;   propagating the object through the valve assemblies to cause the valve assemblies to expose control ports of the valve assemblies; and   pressurizing the string to jointly apply pressure to the control ports of the valve assemblies to cause the valve assemblies to open radial fluid communication ports between a passageway of the string and a region outside of the string.   
     
     
         2 . The method of  claim 1 , wherein propagating the object through the valve assemblies comprises:
 landing the object in a first valve assembly of the plurality of valve assemblies; and   using a fluid obstruction formed from the landed object to shift a sleeve of the first valve assembly to expose the at least one control port of the first valve assembly.   
     
     
         3 . The method of  claim 2 , further comprising:
 releasing the object in response to shifting of the sleeve; and   landing the released object in a second valve assembly of the plurality of valve assemblies.   
     
     
         4 . The method of  claim 1 , wherein pressurizing the string comprises shifting sleeves of the valve assemblies to expose the radial fluid communication ports. 
     
     
         5 . The method of  claim 1 , further comprising:
 using the opened radial fluid communication ports to communicate a fracturing fluid to a surrounding formation to perform a fracturing operation.   
     
     
         6 . The method of  claim 1 , wherein propagating the object through the valve assemblies comprises:
 for at least one of the valve assemblies, landing the object in the valve assembly, shifting a sleeve of the valve assembly open, locking the sleeve open and releasing the object to allow the object to pass through the valve assembly.   
     
     
         7 . The method of  claim 1 , wherein pressurizing the string comprises:
 landing the object in a seat downhole of the valve assemblies to create a fluid obstruction;   using the fluid obstruction to pressure the string; and   shifting sleeves of the valve assemblies in response to the pressurization of the string to open the radial fluid communication ports.   
     
     
         8 . The method of  claim 7 , further comprising locking at least one of the sleeves in a position at which the at least one radial fluid communication port of the corresponding valve assembly is open. 
     
     
         9 . A system usable with a well, comprising:
 a string; and   valve assemblies disposed on the string, each valve assembly comprising at least one control port and at least one radial fluid communication port, wherein the valve assemblies are adapted to:
 serially receive an untethered object deployed in the string such that receipt of the object by a valve assembly of the plurality of valve assemblies creates a fluid obstruction to cause the valve assembly to expose the at least one control port of the valve assembly; 
 serially release the untethered object; and 
 jointly respond to pressurization of the string to open the radial fluid communication ports. 
   
     
     
         10 . The system of  claim 9 , wherein a first valve assembly of the plurality of valve assemblies comprises a sleeve adapted to shift to expose the at least one control port. 
     
     
         11 . The system of  claim 10 , wherein the first valve assembly further comprises a seat attached to the sleeve and adapted to receive the object, and seat is adapted to release the object in response to the sleeve being shifted. 
     
     
         12 . The system of  claim 11 , wherein the seat is adapted to expand a cross-sectional size of the seat in response to the sleeve being shifted. 
     
     
         13 . The system of  claim 10 , further comprising a lock adapted to lock the sleeve in the shifted position to secure the at least one control port open. 
     
     
         14 . The system of  claim 9 , further comprising packers disposed on the string to form an isolated stage of the well containing the valve assemblies. 
     
     
         15 . The system of  claim 9 , wherein a first valve assembly of the plurality of valve assemblies comprises a sleeve adapted to shift to expose the at least one radial fluid communication port. 
     
     
         16 . The system of  claim 15 , further comprising a lock adapted to lock the sleeve in the shifted position to secure the at least one radial fluid communication port open. 
     
     
         17 . An apparatus usable with a well, comprising:
 a housing comprising at least one radial communication port and at least one control port;   a first sleeve slidably attached to the housing to control fluid communication through the radial communication port in response to pressure being exerted at least one control port;   a second sleeve slidably attached to the housing and adapted to be shifted to expose the control port; and   a seat attached to the second sleeve and adapted to receive an untethered object, cause the second sleeve to shift in response to a fluid obstruction created by the seat receiving the untethered object, and release the received object in response to the shifting of the second sleeve.   
     
     
         18 . The apparatus of  claim 17 , wherein the seat is adapted to radially expand to release the object. 
     
     
         19 . The apparatus of  claim 18 , further comprising a locking device adapted to secure the first sleeve in the shifted position. 
     
     
         20 . The apparatus of  claim 18 , further comprising a C-ring or a collet attached to the seat to configure the seat to radially expand and contract.