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