Method and apparatus for completing lateral channels from an existing oil or gas well

Abstract

A method and apparatus for completing a lateral channel from an existing oil or gas well includes a well perforating tool for perforating a well casing at a preselected depth, and a lateral alignment tool for directing a flexible hose and blaster nozzle through a previously made perforation in the casing to complete the lateral channel. The disclosed apparatus also is effective to provide an expanded groove within the earth strata beyond the well casing. The apparatus eliminates the need to maintain the precise alignment of a downhole “shoe” in order to direct the flexible hose and blaster nozzle through a previously made perforation through the well casing.

1 . A well perforating tool having a substantially cylindrical body having a proximal end and a distal end and defining a circumferential wall of the perforating tool, said perforating tool having a longitudinal axis and comprising an axial blind bore open to said proximal end of the perforating tool and defining an axial flow passage within the perforating tool, a hole provided through the distal end of said tool, said hole having a lateral dimensions smaller than the diameter of said blind bore, and at least one lateral port located in the circumferential wall of said perforating tool, said lateral port providing fluid communication between said axial flow passage and a position exterior of said perforating tool, said lateral port being adapted to accommodate a jet of high pressure cutting fluid for perforating a well casing.  
   
   
       2 . A well perforating tool according to  claim 1 , comprising a plurality of said lateral ports.  
   
   
       3 . A well perforating tool according to  claim 1 , comprising upset tubing operatively connected to said tool and being adapted to convey said cutting fluid to said tool.  
   
   
       4 . A well perforating tool according to  claim 1 , said lateral port being provided as a port hole in an abrasion resistant insert, said abrasion resistant insert being disposed within an aperture drilled or punched substantially radially through the circumferential wall of said perforating tool.  
   
   
       5 . A well perforating tool according to  claim 4 , said abrasion resistant insert being made from carbide material.  
   
   
       6 . A well perforating tool according to  claim 4 , said abrasion resistant insert being made from tungsten carbide.  
   
   
       7 . A well perforating tool according to  claim 4 , comprising a plurality of said lateral ports.  
   
   
       8 . A well perforating tool according to  claim 1 , further comprising a chamfered edge provided about the perimeter of said hole located at an interior surface of said distal end of said tool.  
   
   
       9 . A well perforating tool according to  claim 1 , further comprising a plug member that is dimensioned and adapted to close the hole in said distal end of said tool during operation thereof.  
   
   
       10 . A well perforating tool according to  claim 8 , said hole in said distal end of said tool being a circular hole, said tool further comprising a spherical plug member having a diameter that is selected to be received and seated against said chamfered edge to thereby close said hole during operation of said tool.  
   
   
       11 . A well perforating tool according to  claim 10 , said spherical plug member being a steel ball bearing.  
   
   
       12 . An apparatus comprising: 
 a lateral channel alignment tool comprising a substantially elongate basic body having a longitudinal axis, a lateral alignment member pivotally attached to the basic body, and a biasing mechanism effective to bias said lateral alignment member in an angled or laterally engaged position relative to said basic body, said basic body having a longitudinal passage therethrough that is radially offset relative to the longitudinal axis of said basic body and adapted to accommodate a hose therein, said lateral alignment member comprising a first portion that extends generally lengthwise, a terminal portion that extends at an angle relative to the lengthwise direction of the first portion, and an elbow-shaped passage provided within the lateral alignment member, said elbow-shaped passage extending through said respective first and terminal portions of said lateral alignment member from an entrance located in said first portion to an exit located in said terminal portion, said entrance of said elbow-shaped passage being located adjacent a distal end of said longitudinal passage in said basic body and being adapted to receive a blaster nozzle and associated hose therefrom; and    a hose received within both said longitudinal passage and said elbow-shaped passage, said hose comprising a first hose section, a second hose section, and a thruster coupling including a thruster port, wherein said first hose section and said second hose section are operatively connected by said thruster coupling, said thruster port being actuable based on fluid pressure in said hose.    
   
   
       13 . An apparatus according to  claim 12 , said thruster port comprising a valve having a characteristic cracking pressure such that when said fluid pressure is above the cracking pressure, said valve is opened and fluid is permitted to jet out of said thruster port through said valve, and when said fluid pressure is below the cracking pressure, said valve is closed and fluid is not permitted to jet out of said thruster port.  
   
   
       14 . A lateral channel alignment tool according to  claim 13 , comprising a plurality of said thruster couplings provided along the length of said hose, each said thruster coupling having a thruster port including a valve having a characteristic cracking pressure.  
   
   
       15 . A lateral channel alignment tool according to  claim 14 , wherein the thruster couplings and their associated thruster ports are arranged so that their respective valves, at least some of which having different characteristic cracking pressures, are provided at desired locations along the length of said hose.  
   
   
       16 . A lateral channel alignment tool according to  claim 12 , said elbow-shaped passage being adapted to direct said hose, received from said longitudinal passage, out said exit located in said terminal portion to bore a lateral channel in an adjacent formation of earth.  
   
   
       17 . A method of completing a lateral channel from an existing oil or gas well having a well casing, comprising the steps of: 
 providing a well perforating tool having a substantially elongate body defining a circumferential wall of the perforating tool, said perforating tool having a longitudinal axis and comprising an axial blind bore open to a proximal end of said perforating tool and defining an axial flow passage within the perforating tool, and at least one lateral port located in the circumferential wall of said perforating tool, said lateral port providing fluid communication between said axial flow passage and a position exterior of said perforating tool;    suspending said well perforating tool at a selected depth in said existing well; and    pumping a fluid at high pressure through said axial flow passage such that a jet of said high pressure fluid shoots out from said lateral port, said jet perforating said well casing and cutting away a portion of earth strata beyond said well casing.    
   
   
       18 . A method according to  claim 17 , further comprising operating said well perforating tool to produce a perforation in said well casing about the circumference thereof, and further to cut a circular groove in the earth strata beyond said well casing.  
   
   
       19 . A method according to  claim 18 , said perforation in said casing and said groove in the earth strata having approximately the same height and being aligned with one another.  
   
   
       20 . A method according to  claim 18 , wherein said well includes a cement encasement surrounding said well casing, said cutting tool being operated to produce a perforation in said cement encasement about the circumference thereof, in addition to the perforation in said well casing and the circular groove cut in the earth strata.  
   
   
       21 . A method according to  claim 20 , the perforations provided in said well casing and in said cement encasement and the groove cut in said strata all cooperating to provide a composite groove that expands radially outward from said well.  
   
   
       22 . A method according to  claim 18 , further comprising the steps of: 
 providing a lateral channel alignment tool comprising a substantially elongate basic body having a longitudinal axis, a lateral alignment member pivotally attached to the basic body, and a biasing mechanism effective to bias said lateral alignment member in an angled or laterally engaged position relative to said basic body, said basic body having a longitudinal passage therethrough adapted to accommodate a hose therein, said lateral alignment member comprising a first portion that extends generally lengthwise, a terminal portion that extends at an angle relative to the lengthwise direction of the first portion, and an elbow-shaped passage provided within the lateral alignment member, said elbow-shaped passage extending through said respective first and terminal portions of said alignment member from an entrance located in said first portion to an exit located in said terminal portion, said entrance of said elbow-shaped passage being located adjacent a distal end of said longitudinal passage in said basic body and being adapted to receive a blaster nozzle and associated hose therefrom;    advancing said lateral channel alignment tool in said well until the terminal portion of said lateral alignment member reaches and engages through said perforation and into said groove in the earth strata; and    providing a flexible hose and directing it through said elbow-shaped passage in said lateral alignment member, out through the exit thereof and into engagement with the earth strata to cut a channel through the strata.    
   
   
       23 . A method according to  claim 22 , wherein said hose is a flexible high-pressure hose comprising a plurality of thruster ports disposed at spaced intervals along the length thereof, the method further comprising actuating said thruster ports based on fluid pressure within said flexible high-pressure hose.  
   
   
       24 . A method according to  claim 22 , said lateral channel alignment tool further comprising an extensible hose guide member provided in said lateral alignment member and effective to extend from the distal end of said terminal portion of said lateral alignment member to help guide a high-pressure hose fed through said elbow-shaped passage and exiting therefrom into engagement with the strata.  
   
   
       25 . A method according to  claim 24 , said hose guide member comprising a series of guide sections, each said guide section having a horizontal and two opposing vertical plate portions that cooperate to provide a substantially U-shaped cross-section, wherein each guide section is joined to adjacent guide section(s) via a pivot joint, a first guide section having a locking flange provided extending forward from the underside of a first horizontal plate portion thereof, said flange having an upper surface that extends substantially parallel to the bottom face of said first horizontal plate portion, said flange being effective to prevent a successive, second horizontal plate portion of a successive, second guide section from pivoting below the plane of the first horizontal plate portion of the first guide section.