Drilling apparatus and system for drilling wells

Abstract

A device for boring a well is provided, the device being attached to a motor having a power shaft for imparting rotational movement responsive to a fluid flow. The device includes a driver operatively connected to the power shaft, the driver having a tubular body with an internal bore for accommodating fluid flow, a first bit connected to the driver at a first end so that rotational movement of the driver is imparted to the first bit, and an inner bore. A second bit is attached to housing about the first bit. A nozzle communicating the internal portion of the tubular body with an outer portion thereof, the nozzle being oriented to deliver a portion of the fluid flow to the second bit.

1 . A device for boring a well, the device comprising:
 a driver comprising a first end and a second end, wherein the first end of the driver is operatively connected to a power shaft of a motor for receiving rotational force;   a first bit attached to the second end of the driver;   a second bit attached to the driver at a point between the first end and the second end;   at least one fluid passage comprising a nozzle, wherein said at least one fluid passage communicates between an internal bore of the driver and an exterior of the driver, wherein said at least one fluid passage is disposed between the first bit and the second bit, and wherein said at least one fluid passage, the nozzle, or combinations thereof are angled toward the second bit such that fluid passing through the nozzle flows in an uphole direction to contact the second bit.   
   
   
       2 . The device of  claim 1 , further comprising at least one bearing assembly operatively disposed between the driver and a housing disposed about the driver for transferring axial and lateral loads generated during drilling. 
   
   
       3 . The device of  claim 2 , wherein said at least one bearing assembly comprises a thrust mandrel and a plurality of ball bearings operatively associated with the thrust mandrel. 
   
   
       4 . The device of  claim 2 , wherein said at least one bearing assembly comprises a first end and a second end, and wherein an end of the housing is rotatably associated with the first end of said at least one bearing assembly for facilitating rotation of the first bit and the second bit. 
   
   
       5 . The device of  claim 1 , wherein the first bit comprises a first set of cutter teeth positioned to drill a well in a first rotational direction, and wherein the second bit comprises a second set of cutter teeth positioned to drill the well in a counter rotational direction opposite the first rotational direction. 
   
   
       6 . The device of  claim 1 , wherein the first bit is offset relative to the second bit such that the first bit extends farther into a well relative to the second bit. 
   
   
       7 . The device of  claim 1 , further comprising a casing string disposed in communication with the driver, wherein the casing string is in fluid communication with the first bit. 
   
   
       8 . The device of  claim 1 , further comprising a flow skirt disposed between said at least one fluid passage and the second bit for further directing fluid flow to the second bit. 
   
   
       9 . The device of  claim 8 , wherein the flow skirt comprises a ring member having an angled surface that extends to a radially flat surface. 
   
   
       10 . A device for boring a well, the device comprising:
 a driver comprising a first end and a second end, wherein the first end of the driver is operatively connected to a power shaft of a motor for receiving rotational force;   a first bit attached to the second end of the driver;   a second bit attached to the driver at a point between the first end and the second end;   at least one fluid passage comprising a nozzle, wherein said at least one fluid passage communicates between an internal bore of the driver and an exterior of the driver, and wherein said at least one fluid passage is disposed between the first bit and the second bit; and   a flow skirt disposed between said at least one fluid passage and the second bit for directing fluid flow from said at least one fluid passage to the second bit.   
   
   
       11 . The device of  claim 10 , wherein the flow skirt comprises a ring member having an angled surface that extends to a radially flat surface. 
   
   
       12 . The device of  claim 10 , wherein said at least one fluid passage, the nozzle, or combinations thereof are angled toward the second bit such that fluid passing through the nozzle flows in an uphole direction to contact the second bit 
   
   
       13 . The device of  claim 10 , further comprising at least one bearing assembly operatively disposed between the driver and a housing disposed about the driver for transferring axial and lateral loads generated during drilling. 
   
   
       14 . The device of  claim 13 , wherein said at least one bearing assembly comprises a thrust mandrel and a plurality of ball bearings operatively associated with the thrust mandrel. 
   
   
       15 . The device of  claim 13 , wherein said at least one bearing assembly comprises a first end and a second end, and wherein an end of the housing is rotatably associated with the first end of said at least one bearing assembly for facilitating rotation of the first bit and the second bit. 
   
   
       16 . The device of  claim 10 , wherein the first bit comprises a first set of cutter teeth positioned to drill a well in a first rotational direction, and wherein the second bit comprises a second set of cutter teeth positioned to drill the well in a counter rotational direction opposite the first rotational direction. 
   
   
       17 . The device of  claim 10 , wherein the first bit is offset relative to the second bit such that the first bit extends farther into a well relative to the second bit. 
   
   
       18 . The device of  claim 10 , further comprising a casing string disposed in communication with the driver, wherein the casing string is in fluid communication with the first bit. 
   
   
       19 . A method for boring a well, the method comprising the steps of:
 rotating a first bit in a first direction to thereby cause the first bit to bore into a formation, wherein rotation of the first bit produces a first torque;   rotating a second bit in a second direction opposite the first direction to cause the second bit to bore into the formation, wherein rotation of the second bit produces a second torque equal and opposite the first torque, thereby minimizing effects of the first torque; and   flowing drilling fluid in an uphole direction to contact the second bit.   
   
   
       20 . The method of  claim 19 , wherein the step of rotating the first bit in the first direction comprises rotating a drive member of a motor in operative communication with the first bit. 
   
   
       21 . The method of  claim 20 , wherein the step of rotating the second bit in the second direction comprises transferring rotational force from the drive member to at least one associated gear or pinion to change the direction of the rotational force, and transferring the rotational force from said at least one associated gear or pinion to the second bit. 
   
   
       22 . The method of  claim 20 , wherein the step of flowing drilling fluid in the uphole direction to contact the second bit comprises providing the drilling fluid through at least one fluid passage disposed between the first bit and the second bit, wherein said at least one fluid passage is angled in the uphole direction. 
   
   
       23 . The method of  claim 20 , wherein the step of flowing drilling fluid in the uphole direction to contact the second bit comprises contacting the drilling fluid with a flow skirt disposed between the first bit and the second bit, wherein the flow skirt comprises an angled surface for directing the drilling fluid to the second bit.