Autonomous valve, system, and method

Abstract

An autonomous valve including a housing; a chamber defined within the housing; and a piston in sealed movable contact with the housing, the piston having a piston area exposed to fluid within the chamber, and the piston having another piston area exposed to an environment outside of the housing. A Steam Assisted Gravity Drainage (SAGD) System including a producer well having a valve as in any previous embodiment and a method for controlling a Steam Assisted Gravity Drainage (SAGD) System including injecting steam through an injector well into a formation in thermal contact with the system; automatically admitting, reducing or denying entry of fluid to a producer well through a valve based upon both of temperature and pressure.

1 . An autonomous valve comprising:
 a housing;   a chamber defined within the housing; and   a piston in sealed movable contact with the housing, the piston having a piston area exposed to fluid within the chamber, and the piston having another piston area exposed to an environment outside of the housing.   
     
     
         2 . The valve as claimed in  claim 1  wherein the piston includes a closure member. 
     
     
         3 . The valve as claimed in  claim 2  wherein the closure member is interactive with a port of a tubular, the closure member being configured to render the port open, choked or closed. 
     
     
         4 . The valve as claimed in  claim 2  wherein a portion of the housing is spaced from the tubular such that environmental fluid surrounds the portion of the housing during use. 
     
     
         5 . The valve as claimed in  claim 2  wherein the valve includes an insulator between the tubular and the housing. 
     
     
         6 . The valve as claimed in  claim 1  wherein the piston is movable based upon a combination of temperature and pressure applied to the valve. 
     
     
         7 . The valve as claimed in  claim 1  wherein the valve responds to changes in temperature depending upon the pressure. 
     
     
         8 . The valve as claimed in  claim 1  wherein the piston moves when pressure and temperature on a graph intersect at a point on a saturation curve line for a particular fluid in the chamber different than a point on the saturation curve line where temperature and pressure intersected immediately previously. 
     
     
         9 . The valve as claimed in  claim 8  wherein the piston extends from the housing when temperature and pressure intersect on the saturation curve line at a point consistent with more steam evolution than the point at which temperature and pressure intersected immediately previously. 
     
     
         10 . The valve as claimed in  claim 8  wherein the piston retracts into the housing when temperature and pressure intersect on the saturation curve line at a point consistent with less steam evolution than the point at which temperature and pressure intersected immediately previously. 
     
     
         11 . The valve as claimed in  claim 1  wherein the valve further includes a fluid in the chamber. 
     
     
         12 . The valve as claimed in  claim 11  wherein the fluid is selected to possess a particular saturation curve. 
     
     
         13 . The valve as claimed in  claim 11  wherein the fluid is selected to possess a different saturation curve than fluid surrounding the chamber. 
     
     
         14 . The valve as claimed in  claim 1  wherein the valve further includes a biasing member in bias transmitting connection with the piston. 
     
     
         15 . The valve as claimed in  claim 14  wherein the biasing member biases the piston to an extended position relative to the housing. 
     
     
         16 . The valve as claimed in  claim 14  wherein the biasing member biases the piston to a retracted position relative to the housing. 
     
     
         17 . A Steam Assisted Gravity Drainage (SAGD) System comprising:
 a producer well having a valve as claimed in  claim 1 .   
     
     
         18 . The system as claimed in  claim 17  further comprising a heated fluid source. 
     
     
         19 . The system as claimed in  claim 17  further including an injector well. 
     
     
         20 . A method for controlling a Steam Assisted Gravity Drainage (SAGD) System comprising:
 injecting steam through an injector well into a formation in thermal contact with the system;   automatically admitting, reducing or denying entry of fluid to a producer well through a valve as claimed in  claim 1  based upon both of temperature and pressure.