Downhole cutting tool

Abstract

An apparatus and method of cutting an object in a wellbore including a downhole cutting tool having a source of abrasive material; a source of high pressure fluid mixable with the abrasive material; a rotatable nozzle section, the nozzle section rotatable due to a source of low pressure fluid acting on a piston surface formed on a sleeve, the sleeve rotationally and axially movable in a body of the tool; whereby the sources of high and low pressure fluid and the abrasive material are housed in the tool.

1 . A method of cutting an object in a wellbore, comprising:
 providing a tool including a rotatable nozzle section and nozzle, a source of high pressure fluid, a source of low pressure fluid, and a source of abrasive material;   running the tool into the wellbore to a predetermined location where the nozzle is adjacent the object;   actuating the tool whereby the nozzle section rotates between 180 and 360 degrees while the high pressure fluid and abrasive are released from the nozzle.   
     
     
         2 . The method of  claim 1 , wherein actuation takes place when an inner portion of the tool is moved relative to an outer portion thereof. 
     
     
         3 . The method of  claim 2 , wherein rotation of the nozzle section takes place as a result of the low pressure fluid acting on a piston surface formed on a rotatable and axially movable sleeve, the sleeve housed in a body of the tool. 
     
     
         4 . The method of  claim 3 , wherein actuation results in an aperture formed in a wall of material adjacent the nozzle. 
     
     
         5 . The method of  claim 4 , wherein the wall of material separates the nozzle from a source of hydraulic control fluid. 
     
     
         6 . A downhole cutting tool, comprising:
 a source of abrasive material;   a source of higher pressure fluid mixable with the abrasive material;   a rotatable nozzle section, the nozzle section rotatable due to a source of lower pressure fluid acting on a piston surface formed on a sleeve, the sleeve rotationally and axially movable in a body of the tool; whereby   the sources of higher and lower pressure fluid and the abrasive material are housed in the tool.   
     
     
         7 . The tool of  claim 6 , wherein the higher pressure fluid is selectively exposed to the nozzle section and the lower pressure fluid is selectively exposed to the piston surface of the sleeve by remotely opening valves in the body of the tool. 
     
     
         8 . The tool of  claim 7 , wherein the valves are opened due to movement of the valves in relation to a housing around each valve. 
     
     
         9 . The tool of  claim 8 , wherein the movement is initially prevented with at least one shear pin. 
     
     
         10 . The tool of  claim 9 , wherein the higher pressure fluid is provided in a high pressure section that includes a higher pressure fluid chamber and a source of pressurized gas, the fluid and gas separated by a piston, the piston having a relatively large piston area adjacent the gas and a relatively small piston area adjacent the fluid. 
     
     
         11 . The tool of  claim 10 , wherein the lower pressure fluid is provided in a low pressure section that includes a lower pressure fluid chamber and a source of pressurized gas separated by a piston. 
     
     
         12 . The tool of  claim 11 , wherein the sleeve includes an upper spiral-shaped groove formed in its outer surface, the groove constructed and arranged to cause the sleeve to rotate as it moves downwards in the tool body, rotation caused by an inwardly facing pin extending into the groove from an inner surface of the body. 
     
     
         13 . The tool of  claim 12 , wherein the sleeve further includes a lower spiral-shaped groove formed in its outer surface, the groove constructed and arranged to cause the nozzle section to rotate as the sleeve moves downwards in the nozzle section, rotation of the nozzle section caused by a lower inwardly facing pin extending into the groove from an inner surface of the nozzle section. 
     
     
         14 . The tool of  claim 13 , wherein the higher pressure fluid, at the time of a cutting operation is at a pressure of about 30,000 psi and the lower pressure fluid is at a pressure of about 300 psi. 
     
     
         15 . The tool of  claim 14 , wherein the tool is constructed and arranged to seat itself in a body of a downhole valve. 
     
     
         16 . The tool of  claim 15 , further including an indicator, the indicator mounted on the tool an constructed and arranged to extend into a recess formed on an inside surface of the body of the downhole valve when the valves of the tool are opened. 
     
     
         17 . The tool of  claim 16 , wherein the object is a wall of material separating the tool from a source of control fluid to operate a replacement safety valve. 
     
     
         18 . The tool of  claim 17 , wherein the cutting operation takes place in an interior of a valve housing, the interior having an eccentric shape whereby the cutting operation results in a cut that does not extend completely around an interior of the valve housing. 
     
     
         19 . An apparatus for rotating a nozzle of a downhole cutter, comprising:
 a body having a rotatable nozzle section at a lower end thereof;   a sleeve housed in the body, the sleeve rotatable and axially movable within the body and including a piston surface formed on an outer surface thereof, the outer diameter of the sleeve enlarged in the area of the piston surface;   a source of pressurized fluid, the fluid selectively usable to act upon the piston surface;   a first spiraling groove formed in an outer surface of the sleeve, the groove housing a first pin, the pin formed on an inner surface of the body;   a second spiraling groove in the outer surface of the sleeve, the second spiraling groove housing a second pin, the pin formed on an inner surface of the rotatable nozzle section; whereby   when the fluid acts on the piston surface, rotational and axial movement of the sleeve within the body and rotation of the nozzle section is determined by the pins and grooves.