Downhole tool with capillary biasing system

Abstract

A downhole tool and capillary biasing system includes a housing; an intrusion fluid contained within a portion of the housing; a capillary biasing member in fluid contact with the intrusion fluid; and a pressure application configuration capable of pressurizing the intrusion fluid within the housing and method.

1 . A downhole tool and capillary biasing system comprising:
 a housing;   an intrusion fluid contained within a portion of the housing;   a capillary biasing member in fluid contact with the intrusion fluid; and   a pressure application configuration capable of pressurizing the intrusion fluid within the housing.   
   
   
       2 . The downhole tool and capillary biasing system as claimed in  claim 1  wherein the intrusion fluid is a non-wetting fluid. 
   
   
       3 . The downhole tool and capillary biasing system as claimed in  claim 2  wherein the non-wetting fluid is a liquid. 
   
   
       4 . The downhole tool and capillary biasing system as claimed in  claim 3  wherein the liquid is water. 
   
   
       5 . The downhole tool and capillary biasing system as claimed in  claim 3  wherein the liquid is a high surface tension organic liquid. 
   
   
       6 . The downhole tool and capillary biasing system as claimed in  claim 1  wherein the liquid is at least one of a metal and a metal alloy. 
   
   
       7 . The downhole tool and capillary biasing system as claimed in  claim 1  wherein the capillary biasing member is a porous matrix. 
   
   
       8 . The downhole tool and capillary biasing system as claimed in  claim 7  wherein the porous matrix is a silica based material. 
   
   
       9 . The downhole tool and capillary biasing system as claimed in  claim 1  wherein the pressure application configuration is a volume changeable enclosure containing the intrusion fluid. 
   
   
       10 . The downhole tool and capillary biasing system as claimed in  claim 1  wherein the pressure application configuration is a hydraulic inlet connector configured to accept a hydraulic control line for application of external pressure. 
   
   
       11 . The downhole tool and capillary biasing system as claimed in  claim 1  wherein the downhole tool is a safety valve having a flow tube biased to a valve closed position by the capillary biasing system. 
   
   
       12 . A method for biasing a downhole tool comprising:
 pressurizing a non-wetting fluid to intrude into a non-wettable matrix within a housing of the downhole tool; and   maintaining the pressure on the fluid until a spring force from the matrix is required.   
   
   
       13 . The method as claimed in  claim 12  further comprising removing the pressure from the matrix and intrusion fluid.