Apparatus and system to remove debris from a laser-extended bore section

Abstract

An apparatus and a system to remove debris generated by using laser light to extend a bore section comprises a body connected to an umbilical and a plurality of coolant injection ports arranged about an inlet to a debris removal passage through the body. The umbilical is used to position the body adjacent a bore wall in a bore section to be extended, laser light is emitted from the apparatus to melt at least a component of a formation material in which the bore is to be extended and to generate globules of melted formation components. A gas is injected into the bore section to disrupt and to sweep at least some of the molten material from a laser path into the debris removal passage as an injected stream of coolant within the passage intercepts the remnants of globules of molten material as they accelerate in the debris removal passage.

We claim: 
     
         1 . A system comprising:
 an umbilical having an elongate gas conduit, an elongate coolant conduit, a debris removal channel and a plurality of elongate optical fibers;   a body, connected at a proximal end to a leading end of the umbilical, and further comprising a distal end with an optical element to condition laser light emitted from a leading end of the plurality of optical fibers, a deployable circumferential seal between the proximal end and the distal end, a debris removal passage therethrough and coupled to a leading end of the debris removal channel, a gas port directed from the body and coupled to a leading end of the gas conduit, and a coolant port directed into the debris removal passage and coupled to a leading end of the coolant conduit;   a pressurized gas source fluidically coupled to a surface end of the gas conduit,   a coolant source fluidically coupled to a surface end of the coolant conduit;   a laser light power generator optically coupled to a surface end of the plurality of optical fibers; and   a debris receiver fluidically coupled to a surface end of the debris removal channel;   wherein gas released into a portion of a bore section into which the body is positioned purges the bore section distal to the circumferential seal to clear a laser path forward of the distal end of the body;   wherein gas released from the gas port into the bore section sweeps molten formation components from a laser-heated portion of the bore wall into the debris removal passage; and   wherein coolant injected from the coolant port into the debris removal passage freezes molten debris components swept from the laser-heated portion of a bore wall to the debris removal passage for removal from the borehole through the debris removal channel.   
     
     
         2 . The system of  claim 1  wherein the circumferential seal of the body is radially outwardly expandable from a retracted mode to an expanded mode to seal an annulus between the exterior of the body and a wall of a borehole in which the body is positioned. 
     
     
         3 . The system of  claim 2  wherein the circumferential seal is pressure-expandable within a borehole using pressurized fluid from one of the gas conduit and the liquid conduit. 
     
     
         4 . The system of  claim 3  wherein the umbilical further comprises:
 a seal deployment valve; and 
 an elongate conductive member having a surface end and a leading end to deliver an activation signal to the seal deployment valve. 
 
     
     
         5 . The system of  claim 1  wherein the pressurized gas is one of an inert gas, carbon dioxide and nitrogen. 
     
     
         6 . The system of  claim 1  wherein the coolant is one of water, potassium chloride, deionized water, inhibited glycol and water solutions, and dielectric fluids. 
     
     
         7 . The system of  claim 1  wherein the debris removal passage is generally central to the body. 
     
     
         8 . The system of  claim 1  wherein an interior wall of the debris removal passage comprises one of aluminum, aluminum alloy, steel, steel alloy and ceramic. 
     
     
         9 . The system of  claim 1  wherein the coolant injection port comprises:
 a plurality of coolant injection ports angularly distributed about an inlet to the debris removal passage to provide a generally convergent injection pattern to freeze entering molten debris. 
 
     
     
         10 . The system of  claim 1  wherein the at least one gas injection port directed away from the body and coupled to a laser emitting end of the gas conduit comprises:
 a plurality of gas injection ports angularly distributed about the body and proximal to the laser emitting end of the body; 
 wherein the plurality of gas injection ports are directed anterior to the laser emitting end of the body to sweep molten debris radially inwardly to the debris removal passage. 
 
     
     
         11 . The system of  claim 1  wherein the debris receiver operates at a pressure that is substantially lower than the pressure at which liquid and gas is injected into the borehole to promote sweeping of debris produced by impingement of laser light on a portion of the wall of the borehole proximal to the laser emitting end of the body into the debris removal passage of the body. 
     
     
         12 . The system of  claim 1  further comprising:
 a plurality of secondary coolant injection ports on the body to inject a stream of coolant directed generally longitudinally along the interior wall of the debris removal passage of the body. 
 
     
     
         13 . An apparatus comprising:
 a body having a debris removal passage therethrough, an emitting end with an optical laser light focusing element, a connected end opposite the emitting end, and a radially outwardly deployable circumferential seal therebetween; and   an umbilical having a gas conduit connected to supply pressurized gas to a plurality of angularly-distributed gas injection ports on the body, a coolant conduit connected to supply coolant to a plurality of angularly-distributed coolant injection ports on the body, a plurality of optical fibers connected to supply laser light to the optical laser light focusing element, and a debris removal channel connected to remove conditioned debris received from a bore section through the debris removal passage of the body;   wherein deployment of the deployable seal with the body positioned within a bore section enables a portion of the bore section adjacent to the emitting end of the body to be isolated from a portion of the bore section adjacent to the umbilical;   wherein the gas injection ports of the body are directed to sweep melted formation components from a laser-heated portion of a bore wall generally opposite a laser path from the emitting end of the body; and   wherein the coolant injection ports of the body are directed to provide a radially-convergent injection pattern to freeze molten debris swept into the debris removal passage of the body.   
     
     
         14 . The apparatus of  claim 13  wherein the circumferential seal of the body is radially outwardly expandable upon deployment from a retracted mode to an expanded mode to provide a seal between the exterior of the body and a wall of a bore section in which the body may be disposed. 
     
     
         15 . The apparatus of  claim 14  wherein the circumferential seal is selectively deployable using pressurized fluid provided to the body by one of the gas conduit and the coolant conduit. 
     
     
         16 . The apparatus of  claim 13  wherein the umbilical further comprises:
 a seal deployment valve; and 
 an elongate conductive member to deliver an activation signal to the seal deployment valve. 
 
     
     
         17 . The apparatus of  claim 13  wherein the pressurized gas is one of an inert gas, carbon dioxide and nitrogen. 
     
     
         18 . The apparatus of  claim 13  wherein the coolant is one of water, potassium chloride, deionized water, inhibited glycol and water solution, and dielectric fluid. 
     
     
         19 . The apparatus of  claim 13  wherein the debris removal passage is generally central to the body. 
     
     
         20 . The apparatus of  claim 13  wherein the interior wall of the debris removal channel comprises at least one of aluminum, an aluminum alloy, steel, a steel alloy and ceramic. 
     
     
         21 . The apparatus of  claim 13  wherein the plurality of angularly-distributed coolant injection ports on the body are directed to a center of a debris removal passage of the body coupled to a leading end of the debris removal channel of the umbilical; and
 wherein the plurality of coolant injection ports provide a generally convergent injection pattern of coolant to freeze molten debris entering the debris removal passage of the body. 
 
     
     
         22 . The apparatus of  claim 13  wherein the gas conduit connected to supply pressurized gas to a plurality of angularly-distributed gas injection ports on the body comprises:
 a plurality of gas injection ports angularly distributed about the body and disposed proximal to the emitting end of the body; 
 wherein the plurality of gas injection ports provide a gas stream directed anterior to the emitting end of the body to sweep molten debris radially inwardly to a throat of the debris removal passage of the body. 
 
     
     
         23 . The apparatus of  claim 13  further comprising:
 a debris receiver coupled to a surface end of the debris removal channel of the umbilical and operable at a pressure substantially less than the pressure at which gas is injected into the bore section to sweep molten formation components into the debris removal passage of the body. 
 
     
     
         24 . The apparatus of  claim 13  further comprising:
 a plurality of secondary coolant injection ports on the body to inject a stream of coolant directed generally longitudinally along the interior wall of the debris removal passage of the body.