Casing Debris Cleaner

Abstract

A downhole tool cleans debris from a subsea well with nozzle assemblies that selectively deploy from the tool. The nozzle assemblies are in fluid communication with an annulus of a drill pipe on which the downhole tool is mounted, so that fluid pumped into the drill pipe discharges from nozzles provided with the nozzle assemblies. The nozzle assemblies are strategically situated so that when deployed, a stream discharged from nozzles on the assemblies clears debris from a surface between a casing hanger and wellhead housing. The nozzle assemblies are coupled to an annular piston coaxially set on the tool; and sliding the piston axially along the tool deploys the nozzle assemblies. Axially spaced apart ports extend radially through the tool to opposing faces on a head of the piston. Blocking one of the ports with a ball dropped down the drill pipe moves the piston and deploys the assemblies.

What is claimed is: 
     
         1 . A downhole tool for cleaning debris from a subsea well comprising:
 a tool body having an axial bore;   a nozzle assembly on the tool body having a discharge end in selective fluid communication with the bore in the tool body;   a piston selectively movable axially along the tool body; and   a deployment system comprising an elongated member pivotingly coupled to the tool body, the piston, and the nozzle assembly, so that when the piston axially slides along the tool body, the elongated member pivots about the tool body and repositions the nozzle assembly radially outward from the tool body.   
     
     
         2 . The downhole tool of  claim 1 , further comprising an upper port in the tool body that extends radially outward from the axial bore and a lower port in the tool body that extends radially outward from the axial bore and that is spaced axially away from the upper port. 
     
     
         3 . The downhole tool of  claim 2 , wherein the piston has a face in fluid communication with the upper port and an opposing face in selective fluid communication with the lower port, so that when fluid communication is blocked between the opposing face and lower port, the piston axially slides along the tool body. 
     
     
         4 . The downhole tool of  claim 3 , wherein a radius of the axial bore decreases to define a shoulder adjacent the lower port that is strategically profiled to selectively receive a ball for blocking fluid communication between the axial bore and the lower port. 
     
     
         5 . The downhole tool of  claim 1 , wherein the elongated member comprises a first elongated member and the deployment system further comprises a second elongated member having end portions respectively pivotingly attached to the piston and the nozzle assembly and a middle portion pivotingly attached to a middle portion of the first elongated member. 
     
     
         6 . The downhole tool of  claim 1 , wherein the deployment system and nozzle assembly are strategically dimensioned so that when the tool body is inserted into a casing hanger coaxially disposed in a wellhead housing, a cleaning stream discharged from the nozzle assembly is directed into an annulus between the casing hanger and wellhead housing for cleaning debris from within the annulus. 
     
     
         7 . The downhole tool of  claim 1 , further comprising an outer groove along an axial portion the tool body that projects radially inward from an outer circumference of the tool body, and an inner groove that projects radially inward from the outer groove and wherein the piston comprises a tubular body that is axially slidable in the outer groove, and a ring like head projecting radially inward from the tubular body and axially slidable in the inner groove. 
     
     
         8 . A downhole tool for use in forming a wellhead assembly subsea comprising:
 an annular tool body having an axial bore, an upper port extending radially through the tool body, and a lower port extending radially through the tool body;   a piston mounted on the tool body having a face in fluid communication with the upper port and an opposing face in selective fluid communication with the lower port; and   a nozzle assembly selectively movable from a running position stowed adjacent the tool body to a deployed position and that comprises a flow line having an inlet in fluid communication with the upper port and an exit, so that the exit is directed to a designated area in the wellhead assembly.   
     
     
         9 . The downhole tool of  claim 8 , further comprising a deployment means for deploying the nozzle assembly from the running position to the deployed position. 
     
     
         10 . The downhole tool of  claim 9 , wherein the deployment means comprises an elongated member having an end portion pivotingly attached to the tool body, a distal end portion pivotingly attached to the nozzle assembly, and a middle portion coupled with the piston, so that when pressurized fluid is provided to the axial bore while fluid communication between the axial bore and lower port is blocked, pressurized fluid flows through the upper port to the face to axially move the piston thereby rotating the elongated member and urging the nozzle assembly into the deployed position. 
     
     
         11 . The downhole tool of  claim 10 , wherein the elongated member comprises a first elongated member, the deployment means further comprising a second elongated member having end portions pivotingly connected respectively to the piston and the nozzle assembly and a middle portion pivotingly attached to a middle portion of the first elongated member. 
     
     
         12 . The downhole tool of  claim 8 , wherein the lower port is axially displaced from the upper port and wherein the axial bore narrows adjacent the lower port to define a shoulder configured so that when a ball is set on the shoulder, the ball blocks fluid communication between the axial bore and the lower port. 
     
     
         13 . The downhole tool of  claim 8 , wherein the deployment system and nozzle assembly are strategically dimensioned so that when the tool body is inserted into a casing hanger coaxially disposed in a wellhead housing, a cleaning stream discharged from the nozzle assembly is directed into an annulus between the casing hanger and wellhead housing for cleaning debris from within the annulus. 
     
     
         14 . The downhole tool of  claim 8 , further comprising an outer groove along an axial portion the tool body that projects radially inward from an outer circumference of the tool body, and an inner groove that projects radially inward from the outer groove and wherein the piston comprises a tubular body that is axially slidable in the outer groove, and a ring like head projecting radially inward from the tubular body and axially slidable in the inner groove. 
     
     
         15 . The downhole tool of  claim 14 , wherein the head is disposed between the upper and lower ports when the nozzle assembly is in the running position, and is moved to adjacent the lower port when the nozzle assembly is in the deployed position. 
     
     
         16 . The downhole tool of  claim 8 , further comprising connections at upper and lower ends of the tool body for connection to a drill string. 
     
     
         17 . A method of clearing debris from an annulus between a casing hanger and a wellhead housing comprising:
 providing a cleaning tool having a body, an axial bore, a nozzle assembly mounted on the tool body that is in fluid communication with the axial bore, and a deployment means for positioning the nozzle assembly into a cleaning position;   coupling the cleaning tool within a tool string having an annulus that registers with the axial bore;   inserting the tool string into the casing hanger;   pressurizing axial bore by flowing pressurized fluid into the annulus;   deploying the nozzle assembly by selectively providing fluid communication between the axial bore and the deployment means so that a discharge end of the nozzle assembly is directed between the casing hanger and the wellhead housing; and   cleaning an area between the casing hanger and wellhead housing by discharging pressurized fluid from the discharge end of the nozzle.