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 cutting head assembly and a flexible tubular shaft member, wherein the cutting head assembly includes a rotatable nozzle and a cutting head sized and configured to cut laterally into the earthen formation.

What is claimed is: 
     
         1 . An apparatus for cutting laterally into an earthen formation from a wellbore comprising:
 a flexible tubular member formed from a series of interconnectable drive segments, wherein the interconnectable drive segments collectively form 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 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. 
     
     
         3 . The apparatus of  claim 1  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. 
     
     
         4 . The apparatus of  claim 1 , further comprising sorts of flutes or grooves on the drive segments that can facilitate the removal of cuttings. 
     
     
         5 . The apparatus of  claim 1 , wherein the cutting head assembly further comprises a centering member sized and configured to retain the cutting head assembly substantially longitudinal about the axis of a substantially horizontal wellbore created by the apparatus when engaged in cutting laterally into the earthen formation and wherein the cuttings from the earthen formation may travel past the centralizing mechanism toward the wellbore. 
     
     
         6 . The apparatus of  claim 1  further comprising one or more secondary tubular member disposed within the at least one flexible tubular member inner passageway and capable of providing a substantially leak-proof fluid conduit between the pumping source and the cutting head assembly. 
     
     
         7 . The apparatus of  claim 6  further comprising flexible sealing material positioned between the interconnectable drive segments for the creation of a substantially leak-proof fluid passageway within the at least one flexible tubular member inner passageway so as to establish a fluid conduit between the pumping source and the cutting head assembly. 
     
     
         8 . The apparatus of  claim 6 , wherein the substantially leak-proof fluid conduit is created by 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. 
     
     
         9 . 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 sides 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. 
     
     
         10 . The apparatus of  claim 9  comprising interconnectable drive segments having both male teeth and female sockets on each side of the base plane. 
     
     
         11 . The apparatus of  claim 1  comprising two or more interconnectable drive segments having an outer profile that is generally cylindrical or barrel-shaped. 
     
     
         12 . The apparatus of  claim 1  comprising two or more interconnectable drive segments having a base plane situated generally perpendicular to an axis of rotation and having at least one male drive tooth generally situated on one side of the base plan and at least one mating female socket on an opposing side wherein two or more lines bounding an edge of the male tooth do not meet at a single point on one side of the base plane, even if said lines bounding the edge(s) are extended. 
     
     
         13 . The apparatus of  claim 3  being capable of emitting fluid from the at least one orifice on the nozzle providing at least one of the following benefits: keeping the cutting head clean, keeping the cutting head cool, emitting fluid to better dispose the formation to be cut, emitting chemicals for treating the formation, or emitting fluid to provide a medium for carrying formation cuttings back toward the wellbore. 
     
     
         14 . 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. 
     
     
         15 . 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. 
     
     
         16 . The apparatus of  claim 1  further comprising a tensioning means to hold the interconnectable drive segments together. 
     
     
         17 . The apparatus of  claim 16 , wherein the tensioning system is selected from the group comprising: the placement of an elastomeric material between the interconnectable drive segments so as to hold them in tension, the placement of a preload on a hose running through an inner tubular 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, directly, 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. 
     
     
         18 . The apparatus of  claim 1  further comprising a whipstock to guide the interconnectable drive segments. 
     
     
         19 . The apparatus of  claim 18 , wherein the whipstock comprises a passageway through which formation cuttings can pass from the cutting head assembly to a location below the whipstock. 
     
     
         20 . 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. 
     
     
         21 . A method for cutting laterally into an earthen formation from a wellbore comprising:
 guiding a downhole tool assembly comprising a series of interconnectable drive segments, defining at least one 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.   
     
     
         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 method of  claim 22 , wherein the rotational source is activated by the fluid flow through the conduit into the rotational source. 
     
     
         24 . The method of  claim 21 , wherein the interconnected drive segments collectively define a tubular member inner passageway, and the downhole tool assembly further comprises a nozzle defining one or more openings in fluid communication with at least a portion of a secondary tubular member disposed within the tubular member fluid passageway, wherein the method further comprises
 pumping one or more fluids through the secondary tubular member; and   emitting the pumped fluid from the nozzle openings, whereby the fluid contacts the cutting head.   
     
     
         25 . The method of  claim 24 , 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. 
     
     
         26 . The method of  claim 21 , 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. 
     
     
         27 . The method of  claim 21 , further comprising forming a lateral borehole through a pre-existing hole created thru the 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. 
     
     
         28 . The method of  claim 21 , 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. 
     
     
         29 . The method of  claim 21 , 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. 
     
     
         30 . The method of  claim 21 , 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. 
     
     
         31 . The method of  claim 21 , 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.