Apparatus and Method for Lateral Well Drilling

Abstract

An apparatus, method and downhole tool assembly for cutting laterally into an earthen formation from a wellbore.

1 . A drive segment comprising:
 an axis of rotation and a base plane extending perpendicular from the axis of rotation through the center of said drive segment, a first end and a second end;   at least two teeth positioned on each side of the base plane and forming a portion of the first end and second end, each tooth comprising a drive face, a top land and a flank;   at least two webbing sections connecting the at least two teeth, each webbing section comprising a bottom land and forming a portion of the first end and second end, each bottom land adjacent to a tooth drive face;   wherein an angle formed by a drive face and the base plane form an angle of less than 90 degrees;   wherein a series of connected drive segments form a flexible spline member wherein the adjacent drive segments permit articulation and transference of torque of the flexible spline member around a radius;   wherein the intersection of a drive face and top land on a tooth defines a leading edge and wherein a projection of the leading edge defines an offset angle away from the axis of rotation wherein the offset angle ranges from 0 to 5 degrees.   
     
     
         2 . A drive segment comprising:
 an axis of rotation and a base plane extending perpendicular from the axis of rotation through the center of said drive segment, a first end and a second end;   at least two teeth positioned on each side of the base plane and forming a portion of the first end and second end, each tooth comprising a drive face, a top land and a flank;   at least two webbing sections connecting the at least two teeth, each webbing section comprising a bottom land and forming a portion of the first end and second end, each bottom land adjacent to a tooth drive face;   wherein an angle formed by a drive face and its adjoining bottom land form an angle of less than 90 degrees;   wherein a series of connected drive segments form a flexible spline member wherein the adjacent drive segments permit articulation and transference of torque of the flexible spline member around a radius;   wherein the intersection of a drive face and top land on a tooth defines a leading edge and wherein a projection of the leading edge defines an offset angle away from the axis of rotation wherein the offset angle ranges from 0 to 5 degrees.   
     
     
         3 . A drive segment comprising:
 an axis of rotation and a base plane extending perpendicular from the axis of rotation through the center of said drive segment, a first end and a second end;   at least two teeth positioned on each side of the base plane and forming a portion of the first end and second end, each tooth comprising a drive face, a top land and a flank;   at least two webbing sections connecting the at least two teeth, each webbing section comprising a bottom land and forming a portion of the first end and second end, each bottom land adjacent to a tooth drive face;   wherein an angle formed by a drive face and its adjoining top land form an angle of less than 90 degrees;   wherein a series of connected drive segments form a flexible spline member wherein the adjacent drive segments permit articulation and transference of torque of the flexible spline member around a radius;   wherein the intersection of a drive face and top land on a tooth defines a leading edge and wherein a projection of the leading edge defines an offset angle away from the axis of rotation wherein the offset angle ranges from 0 to 5 degrees.   
     
     
         4 . A drive segment comprising:
 an axis of rotation and a base plane extending perpendicular from the axis of rotation through the center of said drive segment, a first end and a second end;   at least two teeth positioned on each side of the base plane and forming a portion of the first end and second end, each tooth comprising a drive face, a top land and a flank;   at least two webbing sections connecting the at least two teeth, each webbing section comprising a bottom land and forming a portion of the first end and second end, each bottom land adjacent to a tooth drive face;   wherein an angle formed by a top land and the base plane form an angle opening towards the axis of rotation of less than 90 degrees;   wherein a series of connected drive segments form a flexible spline member wherein the adjacent drive segments permit articulation and transference of torque of the flexible spline member around a radius.   
     
     
         5 . A drive segment comprising:
 an axis of rotation and a base plane extending perpendicular from the axis of rotation through the center of said drive segment, a first end and a second end;   at least two teeth positioned on each side of the base plane and forming a portion of the first end and second end, each tooth comprising a drive face, a top land and a flank;   at least two webbing sections connecting the at least two teeth, each webbing section comprising a bottom land and forming a portion of the first end and second end, each bottom land adjacent to a tooth drive face;   wherein an angle formed by a bottom land and the base plane form an angle opening towards the axis of rotation of less than 90 degrees;   wherein a series of connected drive segments form a flexible spline member wherein the adjacent drive segments permit articulation and transference of torque of the flexible spline member around a radius.   
     
     
         6 . (canceled) 
     
     
         7 . (canceled) 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . An apparatus for cutting laterally into an earthen formation from a wellbore comprising:
 a flexible spline member formed from a series of interconnectable drive segments, wherein the interconnectable drive segments collectively form at least one inner passageway and a series of interconnectable drive segments permit the articulation and transference of torque of the flexible spline member around a radius;   the flexible spline member being sized and configurable such that an attached cutting head assembly, the at least one inner passageway, and a fluid pumping source may be in fluid communication,   drive segments comprised of any one of  claims 1 - 5 ;   wherein a first flexible spline member end portion is sized and configured to be attachable to a rotation means and a second flexible spline member end portion operatively coupled to the cutting head assembly such that torque applied to the first flexible spline member end portion by the rotational source may be translated to the cutting head assembly.   
     
     
         18 . The apparatus of  claim 17  wherein when torque is applied to a series of connected drive segments the drive segments exert force to self-center and align along the axis of rotation. 
     
     
         19 . The apparatus of  claim 17 , further comprising one or more secondary tubular member disposed within the at least one flexible spline member inner passageway and capable of providing a substantially leak-proof fluid conduit between the pumping source and the cutting head assembly. 
     
     
         20 . The apparatus of  claim 17 , further comprising a whipstock to guide the interconnectable drive segments. 
     
     
         21 . A method for cutting laterally into an earthen formation from a wellbore comprising:
 guiding a downhole tool assembly comprising the apparatus of  claim 17  through a channel defined by a guide assembly and positioning the downhole tool assembly so that the downhole tool assembly contacts a portion of the earthen formation to be laterally cut, wherein the downhole tool assembly is coupled to a conduit, such that the conduit and downhole tool assembly are in fluid communication;   pumping one or more fluids through the conduit and into the downhole tool assembly;   rotating a cutting head of the downhole assembly; and   cutting a borehole into the earthen formation with the cutting head in a direction lateral to the wellbore.   
     
     
         22 . The method of  claim 21 , wherein the downhole tool assembly is operatively connected to a rotational source and the rotational source is coupled to a conduit, such that the conduit, rotational source, and downhole tool assembly are in fluid communication;
 activating the rotational source, wherein a torque is applied to the interconnected drive segments forming a flexible tubular member; and   translating the torque to a cutting head of the downhole tool assembly, wherein the torque causes the cutting head to rotate.   
     
     
         23 . The drive segment of  claim 1 , wherein when torque is applied to a series of connected drive segments the drive segments exert force to self-center and align along the axis of rotation. 
     
     
         24 . The drive segment of  claim 2 , wherein when torque is applied to a series of connected drive segments the drive segments exert force to self-center and align along the axis of rotation. 
     
     
         25 . The drive segment of  claim 3 , wherein when torque is applied to a series of connected drive segments the drive segments exert force to self-center and align along the axis of rotation. 
     
     
         26 . The drive segment of  claim 4 , wherein when torque is applied to a series of connected drive segments the drive segments exert force to self-center and align along the axis of rotation. 
     
     
         27 . The drive segment of  claim 5 , wherein when torque is applied to a series of connected drive segments the drive segments exert force to self-center and align along the axis of rotation.