Apparatus and Method for Lateral Well Drilling

Abstract

A downhole tool assembly for cutting laterally into an earthen formation from a wellbore. The downhole tool assembly includes a flexible tubing circumscribing a series of interconnectable drive segments which can rotate in at least 2 axes on each end, wherein the flexible tubing forms at least one tubular member inner passageway.

1 . An apparatus for cutting laterally into an earthen formation from a wellbore comprising:
 a flexible tubular member comprising a flexible tubing circumscribing a series of interconnectable drive segments which can rotate in at least 2 axes on each end, wherein the flexible tubing forms at least one tubular member inner passageway,   the flexible tubular member being sized and configurable such that an attached cutting head assembly, the at least one tubular member inner passageway, and a fluid pumping source may be in fluid communication,   and wherein a first flexible tubular member end portion is sized and configured to be attachable to a rotation means and a second flexible tubular member end portion is operatively coupled to the cutting head assembly such that torque applied to the first flexible tubular member end portion by the rotational source may be translated to the cutting head assembly.   
     
     
         2 . The apparatus of  claim 1 , wherein the cutting head assembly comprises at least one cutting surface sized and configured to mechanically cut into the earthen formation and wherein the cutting head assembly comprises a nozzle having at least one orifice for the ejection of fluid, gas or combination thereof positioned on or near the cutting head assembly and capable of being in fluid communication with the fluid pumping source. 
     
     
         3 . The apparatus of  claim 1 , wherein the flexible tubing comprises an inside and an outside and when the cutting head assembly is engaged in cutting into the earthen formation cuttings from the earthen formation may travel on the outside of the flexible tubing toward the wellbore and thereby be separated from the interconnectable drive segments. 
     
     
         4 . The apparatus of  claim 1 , wherein the interconnectable drive segments are held together, one to another, either by pin and mating socket mechanisms or collectively by a common tensioning means. 
     
     
         5 . The apparatus of  claim 1 , wherein the wherein the flexible tubing is selected from the group consisting of an elastomeric material, hose, braided-hose, flexible tubing, KEVLAR®, tubing, convoluted tubing, interlocking hose, semi-rigid tubing, and combinations thereof. 
     
     
         6 . The apparatus of  claim 1 , further comprising flutes, grooves or fins on the flexible tubing to facilitate the removal of cuttings from a borehole created upon rotational movement of the cutting head assembly into an earthen formation. 
     
     
         7 . The apparatus of  claim 1 , wherein at least one of the flexible tubular member ends comprises a seal capable of providing a substantially leak-proof fluid conduit between the pumping source and the cutting head assembly. 
     
     
         8 . The apparatus of  claim 1 , wherein at least one of the flexible tubular member ends comprises a bearing mechanism capable of enabling a substantially smooth rotation of the interconnectable drive segments within the flexible tubing. 
     
     
         9 . The apparatus of  claim 1 , wherein the interconnectable drive segments and the flexible tubing are capable of independent rotation. 
     
     
         10 . The apparatus of  claim 1 , comprising two or more interconnectable drive segments each having a base plane situated generally perpendicular to an axis of rotation and having at least two male teeth generally positioned on at least one side of the base plan and having at least two female sockets generally positioned on the opposing side of the base plane, such that the at least two male teeth on one side of the base plane of an interconnectable drive segment can mesh into at least two mating female sockets on an adjacent interconnectable drive segment thereby permitting the articulation and transference of torque of the flexible tubular shaft member around a radius. 
     
     
         11 . The apparatus of  claim 1 , wherein the flexible tubular member is deployed within a wellbore by means selected from the group consisting of production tubing, wireline, slickline unit, coiled tubing, and combinations thereof. 
     
     
         12 . The apparatus of  claim 1 , further comprising a rotational source selected from the group consisting of a fluid-driven motor, an electrical motor, or combinations thereof. 
     
     
         13 . The apparatus of  claim 4 , wherein the tensioning system is selected from the group comprising: the placement of a preload on a hose running through an inner passageway of the flexible tubular shaft member; the placement of a preload on a cable(s) running through an inner passageway of the flexible tubular shaft member; the incorporation of a spring situated above the interconnectable drive segments wherein the spring pushes the interconnectable drive segments together, or pulls the interconnectable drive segments together by pulling tension on a hose, wire or cable(s) running through an inner passageway of the interconnectable drive segments; and combinations thereof. 
     
     
         14 . The apparatus of  claim 1 , further comprising a whipstock comprising an internal guide channel to guide the flexible tubular member. 
     
     
         15 . The apparatus of  claim 14 , wherein the whipstock comprises a passageway through which formation cuttings can pass from the cutting head assembly to a location below the whipstock. 
     
     
         16 . The apparatus of  claim 1 , further comprising a sealing apparatus used in conjunction with a wireline unit allowing fluid communication with surface pumping equipment, said sealing apparatus providing a sealing mechanism between a fluid motor and a tubular extending to the surface through which fluid can be pumped, said sealing mechanism diverting flow from the surface pumping equipment through said tubular and into the fluid motor causing rotation of the motor and attached interconnectable drive segments and ultimately cutting head assembly, said motor connected to a wireline whereby the flexible tubular member may be lowered so as to create a lateral borehole in the earthen formation. 
     
     
         17 . A method for cutting laterally into an earthen formation from a wellbore comprising:
 guiding a downhole tool assembly comprising a flexible tubular member having a flexible tubing circumscribing a series of interconnectable drive segments which can rotate in at least 2 axes on each end, wherein the flexible tubing forms at least one tubular member inner passageway, 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.   
     
     
         18 . The method of  claim 17 , 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.   
     
     
         19 . The method of  claim 17 , wherein the downhole tool assembly further comprises a nozzle on the cutting head defining one or more openings in fluid communication with the tubular member inner passageway, wherein the method further comprises:
 pumping one or more fluids through the tubular member inner passageway; and   emitting the pumped fluid from the nozzle openings on the cutting head.   
     
     
         20 . The method of  claim 19 , wherein the nozzle openings comprise one or more orifices selected from the group consisting of a nozzle orifice at the center of the cutting head, a nozzle orifice(s) that are situated about the radius of the axis of rotation of the nozzle head, a rotating nozzle, a pulsing nozzle, a nozzle that creates a swirling pattern in its discharge flow, a nozzle designed to produce cavitation, and combinations thereof. 
     
     
         21 . The method of  claim 17 , wherein fluid is pumped through a fluid motor so as to rotate the flexible tubular member and the cutting head so as to cut earthen formation. 
     
     
         22 . The method of  claim 17 , further comprising forming a lateral borehole through a pre-existing hole in a casing; said hole created by one or more of the following methods: milling out the section of casing, abrasively cutting the casing, punching through the casing, cutting a hole in the casing, or using chemical to erode the wellbore casing. 
     
     
         23 . The method of  claim 17 , further comprising forming a hole through a wellbore casing and further lowering said tools under rotation so as to cut through any adjacent cement and into the earthen formation. 
     
     
         24 . The method of  claim 17 , further comprising pumping fluid to a location beneath the downhole tool assembly and at a sufficient velocity so as either suspend formation cuttings within the wellbore or to lift the cuttings to the surface. 
     
     
         25 . The method of  claim 17 , further comprising a means to vibrate at least a portion of the downhole assembly so as to mitigate the cutting head and/or flexible tubular member assembly from becoming stuck in the borehole. 
     
     
         26 . The method of  claim 17 , wherein the wellbore is an open hole wellbore and a borehole is formed into the earthen formation in a direction lateral to the open hole wellbore. 
     
     
         27 . A method for cutting laterally into an earthen formation from a cased wellbore comprising:
 positioning a guide assembly, capable of directing a downhole tool assembly adjacent to an earthen formation, within a wellbore;   forming a hole in the wellbore casing;   guiding a downhole tool assembly comprising a flexible tubing circumscribing a series of interconnectable drive segments, wherein the flexible tubing forms at least one inner passageway, through a channel defined by a guide assembly and directing the downhole tool assembly at the hole formed through the wellbore casing, 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 the downhole tool assembly;   activating a rotational source, wherein a torque is applied to the series of interconnectable drive segments;   translating the torque to a cutting head of the downhole tool assembly, wherein the torque causes the cutting head to rotate; and   guiding the downhole assembly through the hole in the wellbore casing and cutting a borehole into the earthen formation with the cutting head in a direction lateral to the wellbore.   
     
     
         28 . The method of  claim 27 , wherein the rotational source is activated by the fluid flow through the conduit into the rotational source. 
     
     
         29 . The method of  claim 1 , wherein the interconnectable drive segments comprise mating ends of adjoining links forming a universal joint allowing rotation about 2 axes on each end. 
     
     
         30 . The method of  claim 1 , wherein the interconnectable drive segments comprise mating ends of adjoining links joined together by a pin and socket mechanism allowing rotation in multiple axes on each end.