Fluid-Driven Dual-Mode Abrasive Perforation Tool

Abstract

A fluid-driven dual-mode abrasive perforation tool which is selectively operable to switch between abrasive and neutral mode is disclosed. In the abrasive mode, jets of abrasive fluid are delivered on to perforate the target site. A ratchet path having mated peaks and valleys on the surface of a J-slot piston included in the tool is engaged with guiding pins. On longitudinal sliding of the piston due to guided inflow and interruption pressurized abrasive fluid through the tool, the guiding pins cause rotation of the piston. Rotation of the piston alternately aligns a pair of flow channels included in the piston with flow paths for ejecting jets of pressurized abrasive fluid and flow paths for non-abrasive ejection of pressurized fluid. When the pair of flow channels of the piston get aligned with flow paths for ejecting jets of pressurized abrasive fluid, the tool is operated in the abrasive mode.

1 - 19 . (canceled) 
     
     
         20 . A fluid-driven dual-mode tool, wherein interrupting and then reinstating the inflow of pressurized fluid into the tool allows starting and stopping forcibly ejected fluid from the tool, comprising:
 a first set of flow paths connecting with a central bore in the tool and exiting on the sides of the tool;   a second set of flow paths connecting with the central bore and exiting into a lower sub of the tool;   a J-slot piston with an outer surface having a ratchet path with alternating peaks and valleys, said ratchet path being engaged with one or more guiding pins fixed on an inner wall of the tool, said J-slot piston further including at least one pair of flow channels extending axially through the J-slot piston;   a spring that applies a force to move the J-slot piston away from entrances of the first and second set of flow paths, and wherein:   downward displacement of the J-slot piston places it adjacent to the entrances of the first and second set of flow paths causes edges of the ratchet path to slide against the pins thereby causing the J-slot piston to rotate until the pins are in between two peaks, and upward displacement causes edges of the ratchet path to slide against the pins thereby causing the J-slot piston to rotate until the pins are in between two valleys, and thereby, alternately align exits of said flow channels with entrances of the first set of flow paths and the second set of flow paths.   
     
     
         21 . The fluid-driven dual-mode abrasive perforator tool of  claim 20 , wherein said tool is deployable in a drill string. 
     
     
         22 . The fluid-driven dual-mode abrasive perforator tool of  claim 21 , wherein when deployed in a drill string, an upper sub of the tool fluidly connects with the interior of the drill string above the tool and the lower sub fluidly connects with the interior of the drill string below the tool. 
     
     
         23 . The fluid-driven dual-mode abrasive perforator tool of  claim 20 , wherein a nozzle is attached into each an exit of the first set of flow paths. 
     
     
         24 . The tool of  claim 20 , wherein downward displacement if the J-slot piston causes compression of said spring. 
     
     
         25 . The tool of  claim 20 , wherein the fluid pressure inflow required to move the J-slot piston up or down is selected based on the known spring compression characteristics. 
     
     
         26 . The tool of  claim 20 , further including a barrel joining the upper sub with the lower sub. 
     
     
         27 . The tool of  claim 20 , further including a sleeve fixed to the inner wall of the tool which has the pins attached on its interior surface. 
     
     
         28 . The tool of  claim 20 , wherein the first set of flow paths has a pair of paths and the second set of flow paths has a pair of paths. 
     
     
         29 . The tool of  claim 28 , wherein the alignment of either the first set of flow paths or the second set of flow paths with the flow channels is achieved when the J-slot piston abuts the entrances the first set of flow paths and the second set of flow paths. 
     
     
         30 . The tool of  claim 29  wherein the J-slot piston abutting the entrances the first set of flow paths and the second set of flow paths respectively causes sealing of the entrances of either the first set of flow paths or the second set of flow paths. 
     
     
         31 . A method of abrading or perforating a target using a fluid-driven dual-mode tool, the method comprising:
 providing a fluid-driven dual-mode abrasive tool, operating as a component in a drill string, wherein interrupting and then reinstating the inflow of pressurized fluid into the tool allows starting and stopping forcibly ejected fluid from the tool, the tool having:
 a first set of flow paths connecting with a central bore in the tool and exiting on the sides of the tool; 
 a second set of flow paths connecting with the central bore and exiting into a lower sub of the tool; 
 a J-slot piston with an outer surface having a ratchet path with alternating peaks and valleys, said ratchet path being engaged with one or more guiding pins fixed on an inner wall of the tool, said J-slot piston further including at least one pair of flow channels extending axially through the J-slot piston; 
 a spring that applies a force to move the J-slot piston away from entrances of the first and second set of flow paths, and wherein:
 downward displacement of the J-slot piston places it adjacent to the entrances of the first and second set of flow paths causes edges of the ratchet path to slide against the pins and causing the J-slot piston to rotate until the pins are in between two peaks, and upward displacement causes edges of the ratchet path to slide against the pins and causing the J-slot piston to rotate until the pins are in between two valleys, and thereby, alternately align exits of said flow channels with entrances of the first set of flow paths and the second set of flow paths; 
 
   placing the tool proximal to the target and   initiating an inflow of pressurized abrasive fluid into the tool to cause downward displacement of the J-slot piston to place it adjacent with the entrances of the first and second set of flow paths and to open the first set of flow paths, thereby causing ejection of jets of pressurized fluid from the exits of the first set of flow paths against said target.   
     
     
         32 . The method of  claim 31 , wherein said tool is deployable in a drill string. 
     
     
         33 . The method of  claim 32 , wherein when deployed in a drill string, an upper sub of the tool fluidly connects with the interior of the drill string above the tool and the lower sub fluidly connects with the interior of the drill string below the tool. 
     
     
         34 . The method of  claim 31 , wherein a nozzle is attached into each an exit of the first set of flow paths. 
     
     
         35 . The method of  claim 31 , wherein downward displacement if the J-slot piston causes compression of said spring. 
     
     
         36 . The method of  claim 31 , wherein the fluid pressure inflow required to move the J-slot piston up or down is selected based on the known spring compression characteristics. 
     
     
         37 . The method of  claim 31 , wherein said tool further includes a barrel joining the upper sub with the lower sub. 
     
     
         38 . The method of  claim 31 , wherein said tool further includes a sleeve fixed to the inner wall of the tool which has the pins attached on its interior surface. 
     
     
         39 . The method of  claim 31 , wherein the first set of flow paths has a pair of paths and the second set of flow paths has a pair of paths. 
     
     
         40 . The method of  claim 31 , wherein the alignment of either the first set of flow paths or the second set of flow paths with the flow channels is achieved when the J-slot piston abuts the entrances the first set of flow paths and the second set of flow paths. 
     
     
         41 . The method of  claim 40 , wherein the J-slot piston abutting the entrances the first set of flow paths and the second set of flow paths respectively causes sealing of the entrances of either the first set of flow paths or the second set of flow paths. 
     
     
         42 . The method of  claim 31 , further including interrupting then reinstating the inflow of pressurized fluid to alternately open one of the first set of flow paths and the second set of flow paths, and to close the other. 
     
     
         43 . The method of  claim 42 , wherein interrupting the inflow of pressurized fluid causes decompression of the spring and sliding of the J-slot piston in upward direction.