Fluid Path between the Outer Surface of a Tool and an Expandable Blade

Abstract

In one aspect of the invention, an expandable tool for an earth boring system comprises a through bore configured to accommodate drilling fluid. A blade is configured to extend and retract out of an outer surface of the tool. A secondary fluid pathway connects the bore with an interface between the outer surface of the tool and a surface of the blade. The secondary pathway directs drilling fluid through the interface.

1 . An expandable tool for an downhole tool string component, comprising;
 a through bore configured to accommodate drilling fluid;   a blade configured to extend and retract out of an outer surface of the tool; and   a secondary fluid pathway connects the bore with an interface between the outer surface of the tool and a blade surface;   wherein the secondary pathway directs drilling fluid through the interface.   
     
     
         2 . The tool of  claim 1 , wherein the bore is formed in a mandrel and the secondary fluid pathway connects an inner and outer circumference of the mandrel. 
     
     
         3 . The tool of  claim 2 , wherein the secondary fluid pathway travels along the outer circumference of the mandrel to the interface. 
     
     
         4 . The tool of  claim 1 , wherein the secondary pathway comprises an outlet formed in the bore. 
     
     
         5 . The tool of  claim 4 , wherein the pathway extends from the outlet to an outer sleeve. 
     
     
         6 . The tool of  claim 5 , wherein the outer sleeve is configured to slide along the mandrel, wherein sliding the sleeve along the mandrel is configured to extend the blade. 
     
     
         7 . The tool of  claim 5 , wherein an inside face of the sleeve and the outer circumference of the mandrel direct fluid to the interface. 
     
     
         8 . The tool of  claim 1 , wherein the secondary pathway is configured to direct drilling fluid to clear debris from the interface. 
     
     
         9 . The tool of  claim 1 , wherein the blade is configured to expand independently of drilling fluid movement. 
     
     
         10 . The tool of  claim 1 , wherein the blade is configured to connect to the outer surface of the tool through a groove, wherein the groove is incorporated in the interface. 
     
     
         11 . The tool of  claim 1 , wherein a piston assembly lies in the secondary fluid pathway. 
     
     
         12 . The tool of  claim 11 , wherein a piston chamber is formed in the piston assembly, wherein the piston chamber comprises a nozzle ring. 
     
     
         13 . The tool of  claim 12 , wherein an aperture lies within the secondary fluid pathway, wherein the aperture directs the fluid to the piston chamber located within the thickness of the mandrel wall. 
     
     
         14 . The tool of  claim 12 , wherein an internal nozzle is formed in the nozzle ring, wherein the internal nozzle is configured to allow fluid to exit the piston chamber through the nozzle ring. 
     
     
         15 . The tool of  claim 14 , wherein the internal nozzle comprises a stopping mechanism configured to halt fluid flow through the piston. 
     
     
         16 . The tool of  claim 12 , wherein the piston chamber is configured to hold a portion of the drilling fluid. 
     
     
         17 . The tool of  claim 12 , wherein the nozzle ring is configured to travel along the outer surface of the mandrel. 
     
     
         18 . The tool of  claim 12 , wherein the nozzle ring is configured to increase a pressure in the drilling fluid. 
     
     
         19 . The tool of  claim 12 , wherein the piston assembly comprises a seal located on an outside width of the nozzle ring configured to stop fluid flow between the piston's width and an inner surface of the piston chamber. 
     
     
         20 . The tool of  claim 1 , wherein at least a portion of the secondary fluid pathway is protected by a wear resistant material.