Flexible hose with thrusters for horizontal well drilling

Abstract

A flexible hose assembly for horizontal well drilling is provided. The flexible hose assembly has a number of spaced thruster couplings along its length to impart drilling force to a nozzle blaster at an end of the flexible hose. The thruster couplings have rearwardly oriented thruster ports which impart a forward drilling force upon exit of high pressure water through the thruster ports. At least one of the thruster ports is an adjustable thruster port having variable opening area, variable discharge angle or both. The opening area and discharge angle can be adjusted or controlled to regulate the amount of thrust imparted to the flexible hose and the nozzle blaster, as well as to clear the bore of debris and prevent its accumulation behind the nozzle blaster. A method of horizontal well drilling using the above-described flexible hose is also provided. The method is particularly useful at shallow depths, such as 50-2000 feet.

What is claimed is:  
     
         1 . A flexible hose assembly for horizontal well drilling comprising a flexible hose, said flexible hose assembly having a proximal end and a distal end, said proximal end being located rearward of said distal end, said flexible hose having a plurality of thruster ports disposed therein with at least one of said thruster ports being disposed rearward of said distal end of said flexible hose assembly, at least one of said thruster ports being adapted to direct a jet of pressurized fluid in a direction such that a centerline drawn through said jet forms an acute discharge angle with the longitudinal axis of said flexible hose rearward from the location of said thruster port, at least one of said thruster ports being an adjustable thruster port.  
     
     
         2 . A flexible hose assembly according to  claim 1 , said flexible hose further comprising a plurality of flexible hose sections and at least one thruster coupling, said thruster coupling being joined to adjacent flexible hose sections, said adjustable thruster port being disposed in said thruster coupling.  
     
     
         3 . A flexible hose assembly according to  claim 2 , further comprising a plurality of said thruster couplings, each thruster coupling having at least one adjustable thruster port.  
     
     
         4 . A flexible hose assembly according to  claim 1 , said hose comprising flexible hydraulic hose rated to withstand at least 5,000 psi.  
     
     
         5 . A flexible hose assembly according to  claim 3 , said thruster couplings being spaced at least 10 feet apart from each other in said hose.  
     
     
         6 . A flexible hose assembly according to  claim 3 , each of said thruster couplings comprising two threaded end sections and a middle section, each of said end sections adapted to mate with a pressure fitting attached to a section of said flexible hose.  
     
     
         7 . A flexible hose assembly according to  claim 1 , said adjustable thruster port having a variable opening area, said jet being discharged from said thruster port through said opening.  
     
     
         8 . A flexible hose assembly according to  claim 1 , said adjustable thruster port having a variable discharge angle.  
     
     
         9 . A flexible hose assembly according to  claim 7 , said adjustable thruster port comprising a shutter for regulating the area of said opening of said thruster port.  
     
     
         10 . A flexible hose assembly according to  claim 9 , said shutter being an iris.  
     
     
         11 . A flexible hose assembly according to  claim 9 , further comprising a servo controller for actuating said shutter to thereby regulate said opening area of said adjustable thruster port.  
     
     
         12 . A flexible hose assembly according to  claim 11 , said servo controller being controlled via wireline or radio signal.  
     
     
         13 . A flexible hose assembly according to  claim 2 , said thruster coupling comprising 2-8 thruster ports evenly spaced around the circumference of said thruster coupling.  
     
     
         14 . A flexible hose assembly according to  claim 8 , said adjustable thruster port comprising a servo-controlled pivot arm, said pivot arm being adjustable to regulate said discharge angle.  
     
     
         15 . A flexible hose assembly according to  claim 14 , said pivot arm being adjustable to provide said discharge angle in the range of 10° to 90° in a rearward direction toward said proximal end of said hose assembly.  
     
     
         16 . A flexible hose assembly according to  claim 1 , said flexible hose being 400-2000 feet in length.  
     
     
         17 . A flexible hose assembly according to  claim 1 , further comprising a nozzle blaster joined to said flexible hose at said distal end of said hose assembly, at least one of said thruster ports being disposed in said flexible hose rearward of the point where said flexible hose joins said nozzle blaster.  
     
     
         18 . A method of horizontal well drilling comprising the following steps: 
 a) providing a flexible hose assembly comprising a flexible hose having a proximal end and a distal end, said proximal end being located rearward of said distal end, said flexible hose having a plurality of thruster ports disposed therein with at least one of said thruster ports being disposed rearward of said distal end of said flexible hose, at least one of said thruster ports adapted to direct a jet of pressurized fluid in a direction such that a centerline drawn through said jet forms an acute discharge angle with the longitudinal axis of said flexible hose rearward from the location of said thruster port, at least one of said thruster ports being an adjustable thruster port;    b) lowering said flexible hose assembly to a desired depth in a vertical well, and redirecting said flexible hose assembly along a direction at an angle to the longitudinal axis of said vertical well;    c) forcing at least 2,000 psi fluid through said flexible hose and said thruster ports in said flexible hose; and    d) drilling a horizontal bore into the earth's strata adjacent said vertical well.    
     
     
         19 . A method according to  claim 18 , said adjustable thruster port having a variable opening area, said jet being discharged from said thruster port through said opening.  
     
     
         20 . A method according to  claim 18 , said adjustable thruster port having a variable discharge angle.  
     
     
         21 . A method according to  claim 19 , said adjustable thruster port comprising a shutter for regulating the area of said opening of said thruster port.  
     
     
         22 . A method according to  claim 21 , said shutter being an iris.  
     
     
         23 . A method according to  claim 21 , further comprising a servo controller for actuating said shutter to thereby regulate said opening area of said adjustable thruster port.  
     
     
         24 . A method according to  claim 23 , said servo controller being controlled via wireline or radio signal.  
     
     
         25 . A method according to  claim 20 , said adjustable thruster port comprising a servo-controlled pivot arm, said pivot arm being adjustable to regulate said discharge angle.  
     
     
         26 . A method according to  claim 25 , said pivot arm being adjustable to provide said discharge angle in the range of 10° to 90° in a rearward direction toward said proximal end of said hose assembly.  
     
     
         27 . A method according to  claim 18 , further comprising the step of drilling a horizontal bore from a vertical well at a depth of 50-2000 feet.  
     
     
         28 . A method according to  claim 18 , further comprising the step of withdrawing said hose assembly from said horizontal bore, and during said withdrawing step forcing fluid through said thruster ports to clean and ream said horizontal bore.  
     
     
         29 . A method according to  claim 18 , said flexible hose assembly further comprising a nozzle blaster attached to said flexible hose at said distal end thereof, at least one of said thruster ports being disposed in said flexible hose rearward of the point where said flexible hose joins said nozzle blaster.  
     
     
         30 . A flexible hose assembly according to  claim 1 , said fluid being aqueous liquid.  
     
     
         31 . A method according to  claim 18 , said fluid being aqueous liquid.  
     
     
         32 . A flexible hose assembly according to  claim 1 , further comprising at least one position indicating sensor.  
     
     
         33 . A flexible hose assembly according to  claim 32 , comprising a plurality of said position indicating sensors provided along the length of said flexible hose assembly.  
     
     
         34 . A flexible hose assembly for horizontal well drilling comprising a flexible hose, said flexible hose assembly having a proximal end and a distal end, said proximal end being located rearward of said distal end, said flexible hose having a plurality of thruster ports disposed therein with at least one of said thruster ports being disposed rearward of said distal end of said flexible hose assembly, at least one of said thruster ports being adapted to direct a jet of pressurized fluid in a direction such that a centerline drawn through said jet forms an acute discharge angle with the longitudinal axis of said flexible hose rearward from the location of said thruster port, each of said thruster ports having an opening with a cross-sectional area selected from the group consisting of closed polygons, closed curvilinear shapes, and shapes having at least one linear edge.