Multi-pressure regulating valve system for expander

Abstract

The present invention provides a method and apparatus for regulating pressure within a closed expansion system. In one aspect of the invention, the apparatus comprises an expander tool comprising a first pressure regulation system disposed within an expansion chamber. The first pressure regulation system comprises two valves which regulate pressure within the expansion system during run-in. In another aspect of the invention, the apparatus comprises an expander tool comprising an expansion chamber in fluid communication with a second pressure regulation system. The second pressure regulation system regulates pressure during the expansion of a tubular. The second pressure regulation system comprises a frangible member and a valve in series, and optionally a pressure regulator downstream of the frangible member and valve in series. In another aspect of the invention, a method is provided for regulating pressure during the expansion process using the first and/or second pressure regulation system.

1 . A method for expanding a tubular within a wellbore, comprising: 
 attaching an expander tool to the lower end of a working string, the expander tool comprising an expansion chamber in fluid communication with a frangible member in series with a valve;    running the working string with the expander tool into the wellbore;    expanding the tubular at a first pressure into substantial contact with a casing wall of the wellbore; and    expanding the tubular at a second pressure.    
     
     
         2 . The method of  claim 1 , wherein the first pressure is higher than the second pressure.  
     
     
         3 . The method of  claim 1 , wherein the frangible member breaks before expanding the tubular at a second pressure.  
     
     
         4 . The method of  claim 3 , wherein the valve operates after the frangible member breaks.  
     
     
         5 . The method of  claim 1 , wherein the frangible member is a burst plug.  
     
     
         6 . The method of  claim 1 , wherein the valve is a check valve.  
     
     
         7 . The method of  claim 1 , wherein the expander tool further comprises a regulator valve in fluid communication with the expansion chamber.  
     
     
         8 . The method of  claim 7 , wherein the regulator valve creates a back pressure on the frangible member in series with the valve, thereby increasing response time of the valve.  
     
     
         9 . The method of  claim 1 , wherein the expander tool further comprises at least two valves which regulate differential pressure between the expansion chamber of the expander tool and an exterior of the expander tool while running the working string with the expander tool into the wellbore.  
     
     
         10 . The method of  claim 9 , wherein the at least two valves comprise a first valve which allows fluid to flow into the exterior of the expander tool.  
     
     
         11 . The method of  claim 10 , wherein the at least two valves further comprise a second valve which allows fluid to flow into the expansion chamber.  
     
     
         12 . The method of  claim 9 , further comprising the step of substantially obstructing flow through the at least two valves before the step of expanding the tubular at a first pressure into substantial contact with a casing wall.  
     
     
         13 . The method of  claim 12 , wherein the substantially obstructing flow through at least two valves further comprises plugging openings of the at least two valves.  
     
     
         14 . An expander tool for expanding a tubular body, the expander tool comprising: 
 an expansion chamber; and    a frangible member in series with a valve in fluid communication with the expansion chamber.    
     
     
         15 . The expander tool of  claim 14 , further comprising a regulator valve in fluid communication with the expansion chamber.  
     
     
         16 . The expander tool of  claim 15 , wherein the regulator valve is located downstream of the frangible member in series with the valve.  
     
     
         17 . The expander tool of  claim 14 , wherein the frangible member bursts upon constraint of the expander tool.  
     
     
         18 . The expander tool of  claim 14 , wherein the frangible member is a burst plug.  
     
     
         19 . The expander tool of  claim 14 , wherein the valve regulates fluid flow at a reduced rate after the frangible member bursts upon constraint.  
     
     
         20 . The expander tool of  claim 15 , wherein the regulator valve operates through a jetting action of a tortuous path of fluid.  
     
     
         21 . The expander tool of  claim 15 , wherein the regulator valve creates a back pressure on the frangible member in series with the valve.  
     
     
         22 . The expander tool of  claim 15 , wherein the regulator valve is a jetted valve.  
     
     
         23 . The expander tool of  claim 14 , further comprising at least two valves disposed inside the expansion chamber.  
     
     
         24 . The expander tool of  claim 23 , wherein the at least two valves regulate differential pressure between the expansion chamber and an outside of the expander tool.  
     
     
         25 . The expander tool of  claim 24 , wherein the at least two valves comprise a first valve which permits pressure from the expansion chamber to release into the outside of the expander tool.  
     
     
         26 . The expander tool of  claim 25 , wherein the at least two valves further comprise a second valve which permits pressure from the outside of the expander tool to release into the expansion chamber.  
     
     
         27 . An expander tool comprising: 
 means for expanding a tubular at a first pressure until the tubular contacts a casing wall of a wellbore; and    means for expanding a tubular at a second pressure after the tubular contacts the casing wall of the wellbore.    
     
     
         28 . The expander tool of  claim 27 , wherein the first pressure is higher than the second pressure.  
     
     
         29 . The expander tool of  claim 28 , further comprising means for regulating the transition between the means for expanding the tubular at the first pressure and the means for expanding the tubular at a second pressure.  
     
     
         30 . The expander tool of  claim 27 , further comprising means for decreasing differential pressure between an inside portion of the expander tool and an outside portion of the expander tool.  
     
     
         31 . A method for expanding a tubular within a wellbore, comprising: 
 running a working string into the wellbore with an expander tool attached to the lower end, the expander tool comprising: 
 an expansion chamber in fluid communication with a frangible member in series with a check valve; and  
 at least two valves;  
   regulating differential pressure between the expansion chamber and an exterior of the expander tool with the at least two valves while running the working string into the wellbore;    expanding the tubular at a first pressure into substantial contact with a casing wall of the wellbore;    allowing sufficient pressure to break the frangible member to accumulate within the expansion chamber; and    expanding the tubular at a second pressure.    
     
     
         32 . An expander tool for expanding a tubular body within a wellbore, the expander tool comprising: 
 an expansion chamber comprising two valves which regulate differential pressure between an inside of the expansion chamber and an outside of the expansion chamber; and    a frangible member in series with a valve in fluid communication with the inside of the expansion chamber.    
     
     
         33 . The expander tool of  claim 32 , further comprising a regulator valve located downstream of the frangible member, wherein the regulator valve is in fluid communication with the expansion chamber.