Abstract: A hookless hanger for a multilateral wellbore can include an assembly with an upper tubular body and a lower tubular body. The upper tubular body can be positioned in a main bore of the wellbore. The lower tubular body can be pivotally coupled to the upper tubular body at a joint. The lower tubular body can pivot relative to the upper tubular body and can be positioned in a lateral bore of the wellbore.

Abstract: A thru-tubing mill with an elongate body having an attachment end and a milling end. The attachment end is attached to a tubing string. The milling end has a semi-torroidal surface defined by a two-dimensional curved line rotated about a central point that is spaced from the curve in a direction that is perpendicular to the curved line and a plurality of curved support members attached to the semi-torroidal surface that extend along the semi-torroidal surface, each curved support members having a first curve similar to the two-dimensional curved line in a first dimension and a second curve that is cambered relative to the two-dimensional curved line in a second dimension. A hard coating is installed on at least one side of the curved support members.

Abstract: Rotary steerable drilling apparatus and methods utilizing apparatus comprising a shaft, a multi-angle strike ring axially repositionable along the shaft, an articulated member coupled to the shaft, and a steering member carried by the articulated member. An actuator is operable to maintain an angular offset of the articulated member relative to the shaft by maintaining azimuthally-dependent contact between the multi-angle strike ring and the steering member.

Abstract: A jet drill coupled to a distal end of a flexible jet lance is lowered into a well casing and advanced through a curved passage formed in a deflection shoe oriented to direct the jet drill through an orifice milled in the well casing. The jet drill is actuated with a pressurized fluid produced by a pump on the surface that is conveyed through a high pressure hose that runs through the flexible jet lance. Force transmitted through a thrust liner of the jet lance advances the jet drill while the lateral bore is being drilled. The thrust liner comprises helical coils of steel wire providing a high elastic modulus and buckling resistance, even while passing through the curved passage. Tension cables in the jet lance maintain tension on the thrust liner and enable the assembly to be pulled from the lateral bore and well.

Abstract: A rotary steerable drilling tool with an electromagnetic steering system can include a drill collar, a bit shaft, an orientation control module, a mud tube, a mud tube coupler, a universal joint, a mud sealing device, and a drill bit. The bit shaft can be mechanically coupled to the drill collar through the universal joint and the orientation control module and rotate about the universal joint. The orientation and the inclination angle of the bit shaft against the drill collar can be controlled by the orientation control module with the electromagnetic steering system. The orientation control module can include a guide track mounted on the inside wall of the drill collar, arrays of electromagnets mounted on the guide track, a positioning frame, a permanent magnet mounted on the positioning frame, a coupling tube, and at least two bearing wheels. A corresponding electromagnetic steering method is also provided.

Abstract: A system and method facilitate drilling of a lateral wellbore by eliminating one or more trips downhole. The system comprises a drill bit optimized for the drilling operation. The drill bit is coupled to a whipstock via a connector, which minimizes interference with the cutting elements of the drill bit. The connector includes a separation device which facilitates disconnection of the drill bit from the whipstock after the whipstock is anchored at a desired downhole location. The separation device is disposed in the connector to minimize the remaining portions of the connector existing after separation of the drill bit from the whipstock which must be milled by the drill bit prior to drilling the lateral wellbore.

Abstract: A system and method facilitate drilling of a lateral wellbore by eliminating one or more trips downhole. The system comprises a drill bit optimized for the drilling operation. The drill bit is coupled to a whipstock via a connector, which minimizes interference with the cutting elements of the drill bit. The connector includes a separation device which facilitates disconnection of the drill bit from the whipstock after the whipstock is anchored at a desired downhole location. The separation device is disposed in the connector to minimize the remaining portions of the connector existing after separation of the drill bit from the whipstock which must be milled by the drill bit prior to drilling the lateral wellbore.

Abstract: A system and method are provided for using controlled vibrations to bias a drilling direction of a bottom hole assembly (BHA) in a borehole. In one example, the system includes a movement mechanism and a vibration control mechanism. The movement mechanism is configured to use mechanical energy provided by a mechanical energy source to enable translational movement of a first surface relative to a second surface to allow the first surface to repeatedly impact the second surface to produce a plurality of vibration beats. The vibration control mechanism is configured to influence a drilling direction in which the BHA is drilling by controlling an amplitude of the vibration beats to regulate an impact force between the first surface and the second surface, where the amplitude is controlled based on directional information corresponding to the BHA.

Abstract: A method for lateral drilling into a subterranean formation whereby a shoe is positioned in a well casing, the shoe defining a passageway extending from an upper opening in the shoe through the shoe to a side opening in the shoe. A rod and casing mill assembly are inserted into the well casing and through the passageway in the shoe until a casing mill end of the casing mill assembly substantially abuts the well casing. The rod and casing mill assembly are rotated until the casing mill end substantially forms a perforation in the well casing. An internally rotating nozzle is attached to an end of a hose and is pushed through the passageway and the perforation into the subterranean formation, and fluid is ejected from tangential jets into the subterranean formation for impinging upon and eroding the subterranean formation.

Abstract: An apparatus and method for penetrating earth strata surrounding a wellbore including a nozzle assembly, a flexible tubing connected to the nozzle assembly, and a means to position the nozzle assembly downhole in a substantially horizontal direction into earthen strata, such that the nozzle assembly is connected to one end of the flexible tubing. Embodiments can provide horizontal jetting into the earth's strata from both cased and uncased wells utilizing a rotating, swirling, pulsing or cavitating nozzles which can keep a relatively cuttings free downhole environment.

Abstract: A directional drilling system for use in drilling a wellbore can include a bit deflection assembly with a bit axis deflection mechanism which applies a deflecting force to a shaft connected to a drill bit. The deflecting force may deflect the shaft, without being reacted between the deflection mechanism and the drill bit. The deflecting force may deflect the shaft between the drill bit and a radial bearing which maintains the shaft centered in the bit deflection assembly. The deflection mechanism may both angularly deflect and laterally displace the bit axis in the deflection mechanism.

Abstract: An internally rotating nozzle for facilitating drilling through a subterranean formation is rotatably mounted internally within a housing connected to a hose for receiving high pressure fluid. The rotor includes at least two tangential jets oriented off of center for ejecting fluid to generate torque and rotate the rotor and cut a substantially cylindrical tunnel in the subterranean formation.

Abstract: An oilfield downhole cutting tool comprises a tool body that comprises a non-cutting stabilizing section. The cutting tool further comprises a plurality of cutters coupled to the tool body forward of the non-cutting stabilizing section, wherein a maximum cutting diameter defined by the cutters is less than 1.1 times a diameter defined by the non-cutting stabilizing section. The cutting tool further comprises a cutting rate limiting component coupled to the tool body.

Abstract: A microtunnelling apparatus and system that includes an external drive system having rotational and linear thrust drive means, a drill head section having drill rotor and drill rod and connecting to intermediate drill rods allowing extension of the boring hole created by the drill head section driven by the drive system. The drill head includes a modular construction having a plurality of circular disc like elements, a bearing module, a steering module, a spacer module, and a mounting module, for axial alignment and abutment and mounting within a cylindrical steering shell. Directional steering of the drill head includes a plurality of substantially radially extending channels in steering module, each with an hydraulically movable protuberance movable by control means to redirect the outer steering casing and thereby redirect the drill head section mounted on the distal end of the drill rods.

Abstract: Whipstocks and deflectors comprising a degradable composition, and methods of using same are described. A degradable composition may consist essentially of one or more reactive metals in major proportion, and one or more alloying elements in minor proportion, with the provisos that the composition is high-strength, controllably reactive, and degradable under defined conditions. Methods of using degradable whipstocks in oilfield operations are also described. This abstract allows a searcher or other reader to quickly ascertain the subject matter of the disclosure. It will not be used to interpret or limit the scope or meaning of the claims. 37 C.F.R. 1.72(b).

Abstract: A borehole network including first and second end surface locations and at least one intermediate surface location interconnected by a subterranean path, and a method for connecting a subterranean path between a first borehole including a directional section and a second borehole including a directional section. A directional drilling component is drilled in at least one of the directional sections to obtain a required proximity between the first and second boreholes. An intersecting component is drilled, utilizing magnetic ranging techniques, from one directional section to provide a borehole intersection between the first and second boreholes, thereby connecting the subterranean path.

Abstract: A jetting hose is conveyed downhole retracted within a tubing string for jetting lateral boreholes from a main wellbore, is released at the jetting depth and pumped from the tubing string and into a lateral borehole with jetting fluid. A piston is secured to the upper end of the jetting hose, and the pumped jetting fluid drives the piston. A speed control regulates the penetration rate of the jetting hose into the formation independent of the tubing string weight.

Abstract: A drilling system is presented for use in drilling lateral boreholes from a main borehole. The drilling system generally comprises a drilling machine, a drill string connected to the drilling machine so as to be driveable in an axial direction, and a guide connected to the drilling machine such that when the drill string is driven axially by the drilling machine, it interacts with the guide so as to be directed in a predetermined radial direction. A method of drilling a lateral borehole from a main borehole is also presented, comprising the steps of: positioning the drilling system in the main borehole; anchoring the guide in the borehole; operating the drilling machine to drive the drill string in an axial direction; and deflecting the drill string, by means of the guide, in a radial direction into the wall of the main borehole to drill the lateral borehole.

Abstract: A direction adjustment tool for a downhole drilling apparatus is disclosed. The tool has a tubular housing adapted to be incorporated into a downhole drilling apparatus, and steering blades mounted to the housing. A drive shaft transmits drive to a drill bit of a drilling apparatus, wherein the shaft defines a passage for transmitting drilling fluid to the drill bit. A first pressure chamber is defined between the housing and the shaft and communicates with the passage, wherein the steering blades are moved from retracted positions to extended positions thereof as a result of increase of fluid pressure the first pressure chamber. A pendulum member is pivotably mounted to extend in a vertical orientation when the shaft is not rotating relative to the housing, and pistons prevent movement of at least one steering blade to the extended position thereof as a result of the angle between a longitudinal axis of the shaft and the longitudinal axis of the pendulum member exceeding a predetermined amount.

Abstract: A slotting device (100) to be used with a rock drilling apparatus (1) to drill closely together a plurality of parallel intersecting holes so as to form a slot in a brittle material, such as rock, masonry or concrete. The slotting device (100) includes a guide portion (110) connected to a body portion (120) with at least one strut (130). The guide portion (110) is disposed in a previously drilled hole, and the body portion (120) and a rotary percussion tool (7) mutually define a variable volume chamber (140) that contains flushing fluid that damps transmission of impact stress waves from a percussion device (4) of the drilling apparatus (1) to the slotting device (100).

Abstract: An oilfield downhole cutting tool is provided. The cutting tool comprises a tool body that comprises a non-cutting stabilizing section. The cutting tool further comprises a plurality of cutters coupled to the tool body forward of the non-cutting stabilizing section, wherein a maximum cutting diameter defined by the cutters is less than 1.1 times a diameter defined by the non-cutting stabilizing section. The cutting tool further comprises a cutting rate limiting component coupled to the tool body.

Abstract: A method and apparatus for milling an item in a wellbore. The method and apparatus including providing a milling tool having one or more blades which are geometrically configured to resist deflection by distributing cutting forces in multiple directions.

Abstract: An apparatus and method for penetrating earth strata surrounding a wellbore including a nozzle assembly, a flexible tubing connected to the nozzle assembly, and a means to position the nozzle assembly downhole in a substantially horizontal direction into earthen strata, such that the nozzle assembly is connected to one end of the flexible tubing. Embodiments can provide horizontal jetting into the earth's strata from both cased and uncased wells utilizing a rotating, swirling, pulsing or cavitating nozzles which can keep a relatively cuttings free downhole environment.

Abstract: An internally rotating nozzle for facilitating drilling through a subterranean formation is rotatably mounted internally within a housing connected to a hose for receiving high pressure fluid. The rotor includes at least two tangential jets oriented off of center for ejecting fluid to generate torque and rotate the rotor and cut a substantially cylindrical tunnel in the subterranean formation.

Abstract: Apparatus for clearing particles from a lateral drilling operation in strata beside a well. The drilling apparatus is part of a down hole unit and is configured for extending from a lateral opening of the unit into a lateral passage in the adjacent strata, and the operation of the drilling apparatus discharges particles from the lateral passage toward the lateral opening. The invention deflects or redirects the particles discharged from the lateral passage, away from the lateral opening, to prevent clogging or blocking of an internal passage or elbow through the down hole unit, using a pressurized fluid such as a gas or an emulsion. The pressurized fluid can also be configured for carrying the particles upwardly through the well to the surface, and for reducing or removing a hydrostatic head in the well.

Abstract: An assembly for milling a window in a tubular features a layout that keeps a restorative force normal to the whipstock slope acting on the window mill to help it track the whipstock ramp long enough for making an exit at the desired location. A string mill assembly is made long enough to allow such a restorative force to be created on the window mill as it advances down the ramp. The bearing or cutting structures on the string mill are positioned with respect to the window mill so that either the top of the string mill or at least the first bearing structure above the window mill presents at the top of the window as the window mill arrives at the position where it is desired that it make an exit. The lower bearing structure of the string mill also preferably has a rounded profile to facilitate its entrance on to the whipstock ramp without getting in a bind on the tubular wall adjacent the top of the window.

Abstract: A method and apparatus for creating inverted laterals or drainholes having an inverted or upwardly inclining bore in a producing interval from a generally vertical wellbore and a method for drilling, completing, and producing from such a drainhole.

Abstract: A method and apparatus for penetrating a side of a well casing and/or drilling into earth strata surrounding the well casing, utilizing a rotating fluid discharge nozzle, and an abrasive introduced into the fluid downstream of apparatus for rotating the nozzle. Apparatus for rotating the nozzle can include a motor operable by pressurized fluid, or another suitable rotating power source The introduction of the abrasives will not adversely affect or harm the apparatus for rotating the nozzle, yet will provide the enhanced drilling capability. The abrasive stream can be used for drilling or cutting through a metal well casing, as well as cement and the adjacent strata.

Abstract: A sidetracking system has a pair of serially connected mills (8, 9), each having a plurality of circumferentially arranged blades having a tapered cutting portion (82, 93) thereon for cutting a window in a casing and then sidetracking in a formation. A whipstock has at least three axially spaced ramps, each ramp being interspaced by a substantially axially extending portion. Each of the ramps has the same angle of inclination to a longitudinal axis and the distance between the ramps is the same as the distance between the tapered portions on the mills (8, 9) so that when, in operation, load is shared between both mills. The mills have a button (83, 93) of hardened material located on the tapered cutting portions so that the button abrades the whipstock ramps (31, 32, 33).

Abstract: A method and device for boring a hole [5] through a material along a desired path includes an umbilical subsystem [2000] connected to a boring subsystem [3000] having a plurality of pulsejets [3100]. These pulsejets [3100] repeatedly receive and ignite a combustible fluid [7] in a combustion chamber [3230] causing a portion of the fluid [7] to be forced out of a nozzle [3260] at high speeds as a fluid slug [10] that impacts materials ahead of the pulsejet [3100]. A controller [3310] controls the amount of fluid provided to each pulsejet [3100], and the firing timing, thereby controlling the intensity in which each slug [10] impacts the material. By modulating the intensity and firing sequence of each of the pulsejets [3100], material ahead of the boring subsystem [3000] is differentially bored thereby allowing steering of the boring subsystem [3000].

Abstract: A flexible lateral drilling shaft is disclosed, having a concentrically nested arrangement of two or more coil springs of which the winding direction of at least one of the springs is opposite to another of the springs. The shaft is included within a lateral drilling tool which includes a deflection assembly having roller bearings to assist the deflection of the flexible shaft. Once inserted into a wellbore, increasing pressure applied to the shaft will cause the opposing springs to stiffen against each other, providing sufficient strength to support the drilling of a lateral drainhole within the wellbore. Further, the spring is wound from a steel wire having a specific noncircular profile to improve the strength characteristics of the shaft without increasing the bending stress during deflection.

Abstract: An apparatus and method for improving the formation of multiple lateral wells in new and pre-existing wellbores, and positive, selective reentry of each lateral well. The apparatus comprises a tubular assembly, which includes an adjustable coupling device and a packer. The method comprises the use of the tubular assembly.

Abstract: An apparatus and method for characterizing a subsurface formation is provided. The apparatus includes a tool body, a probe assembly carried by the tool body for sealing off a region of the borehole wall, an actuator for moving the probe assembly between a retracted position for conveyance of the tool body and a deployed position for sealing off a region of the borehole wall and a perforator extending through the probe assembly for penetrating a portion of the sealed-off region of the borehole wall. The tool may be provided with first and second drilling shafts with bits for penetrating various surfaces. The method involves sealing off a region of a wall of an open borehole penetrating the formation, creating a perforation through a portion of the sealed-off region of the borehole wall and testing the formation.

Abstract: A downhole tool comprises a joint, and a resilient member 65 which extends through the joint and provides a restoring force which tends to strengthen the joint. The joint may comprise a flex coupling 61 which allows limited articulation of the joint. First and second drill string sections 63, 64 may be interconnected by the joint, the resilient member 65 being fixed to interior surfaces of the first and second drill string sections 63, 64. A downhole tool may also comprise primary and secondary sleeves 46 that are supported relative to the mandrel 10 of the drill string. Rotational drive may be transferred from one of the sleeves to the other.

Abstract: A sealed multilateral junction system provides fluid isolation between intersecting wellbores in a subterranean well. In a described embodiment, a method of forming a wellbore junction includes the steps of sealing a tubular string in a branch wellbore to a tubular structure in a parent wellbore. The tubular string may be secured to the tubular structure utilizing a flange which is larger in size than a window formed in the tubular structure. The flange may be sealed to the tubular structure about the window by a metal to metal seal or by adhering the flange to the tubular structure.

Abstract: Enhanced horizontal drilling systems and methods encompass the production of crude oil from wells drilled from a subterranean production facility. This approach has the location of the well head below the oil reservoir to improve flow rate and recovery due to the consistent voiding of fluids by gravity flow within the well bore to the well head allowing well bore production pressure to achieve extremely low fluid pressure or even a vacuum of up to 15 PSI. This method increases oil recovery rate and factor, and lowers production costs. The present method is production of shallow crude oil by way of long horizontal or near horizontal boreholes drilled and serviced from a subsurface workroom. The subsurface workroom serves as both the drilling platform and the place to which production is centrally accumulated from the wells. Oil is collected in a central facility and is then lifted to the surface utilizing pumps.

Abstract: The present invention is a wellhead system for use in completing at least two well bores from within a single conductor housing. The wellhead system comprises at least one wellhead housing which is supported on the conductor housing and which comprises a top portion that is adapted to be connected to a lower portion of a wellhead component, a casing hanger which is supported within the wellhead housing and from which a casing string is suspended, and a connector for securing the wellhead component to the wellhead housing. In accordance with the present invention, the connector is selected from the group consisting of a latch ring and a segmented clamp assembly.

Abstract: Apparatus for boring a hole from an inside of a casing outwardly at an angle relative to a longitudinal axis of the casing comprises a drill shoe having a longitudinal axis and being positionable in the casing, the shoe having first and second passageways which converge into a third passageway exiting the shoe, a torsional load transmitting element and a cutting element connecting to one end of the torsional load transmitting element, the torsional load transmitting element and cutting element being positioned in the first passageway during non-use and in the third passageway during use, and a fluid conduit and a nozzle connected to one end of the fluid conduit, the fluid conduit and nozzle being positioned in the second passageway during non-use and in the third passageway during use.

Abstract: A method and apparatus for predictable downhole milling of a casing window having predetermined location, orientation, dimension and contour geometry. An elongate substantially rigid milling shaft has at least one casing window milling element in fixed relation therewith and has a pilot mill in articulated and rotary driven connection with the milling shaft. The milling shaft is in articulated and rotary driven connection with a rotary drive mechanism. The articulated connection of the pilot mill and milling shaft may incorporate an articulation control system to permit the pilot mill to be maintained substantially coaxial with the milling shaft so that its trajectory at a predetermined stage of window milling can be controlled by the milling shaft when positive guiding by a deflecting tool can no longer be ensured.

Abstract: Apparatus for drilling lateral drainholes from a well casing comprises a flexible shaft having a bit at the lower end; the shaft extending through a shaft guide conduit anchored within the casing adjacent an oil-bearing formation. The “L” shaped guide conduit re-directs the shaft from an path parallel to the casing, through an elbow, to a path substantially perpendicular to the casing. The flexible shaft is formed of a helically wound outer coil spring and one or more helically wound and smaller inner coil springs residing concentrically therein. Each coil spring is closely fitted within the other. Each coil spring is wound opposite in direction to that of the next adjacent coil spring so as to interfere when under torsion. Bushings are located within the elbow for causing the shaft to flex and turn while permitting rotation and axial movement therethrough. A motor imparts torque into the top of the shaft, preferably through an intermediate driveshaft.

Abstract: A joint of tubular casing with a pre-formed window in its sidewall, has a tubular sleeve fixedly attached to the interior of the tubular casing by a plurality of shearable fastners. The exterior surface of the sleeve is sealed to the interior surface of the tubular casing on opposing sides of the window using a pair of high pressure seal assemblies. The window cavity is filled with a fluid and then the window is covered with one or more layers of a composite material such as fiberglass. In use, the joint of tubular casing is run down to the depth of interest in an earth borehole, and then the window is oriented with respect to the formation of interest at the depth. The joint of tubular casing is then cemented in place, after which the tubular sleeve is retrieved by the use of a fishing tool causing the set screws to shear upon the upward movement of the fishing tool. After the interior sleeve is retrieved, a whipstock is lowered into the cased borehole, until it is oriented and anchored therein.

Abstract: In the field of drilling lateral channels from the cased bore of an oil well, a system is presented whereby a number of lateral channels can be drilled through the casing and out a distance into the formation with no requirement to move or raise the lateral drilling apparatus to the surface for each lateral channel drilled. The direction of the drilled lateral channel can be selected by the system operator at the well head. The system will allow the drilling of lateral channels with the well under pressure. A configuration is shown which will allow the installation of a flexible perforated liner in the channel, which flexible perforated liner will prevent the material around the channel from collapsing.

Abstract: An apparatus for providing a high torque pressure sleeve for easily drillable casing exit ports. A joint of tubular casing with a pre-formed window in the wall thereof has a tubular sleeve fixedly attached to the exterior of the tubular casing covering the window. The interior surface of the sleeve is sealed to the exterior of the tubular casing on opposite sides of the window. In use, the joint of the tubular casing is run down to the depth of interest in the earth wellbore and the window is oriented with respect to the formation of interest at the depth. The joint of tubular casing is then cemented in place, after which a whipstock is lowered into the wellbore, oriented and anchored therein. The assembly automatimuly fixes the axial and circumferential oriention of the whipstock within a surrounding casing joint and holds the assembly in place.

Abstract: An apparatus for enhancing production from a well by lowering a tubular conductor into the well to a position in which the conductor extends downwardly from near the surface of the earth to a zone beneath the surface, and a drilling unit is advanced past a whipstock held by the tubular conductor at the predetermined zone, thereby deflecting the drilling unit in a lateral direction through an opening in a side wall of the conductor into the earth formation about the conductor. The whipstock may initially be attached to the drilling unit by a shear connection. An anchor may lock the lower end of the tubular conductor in place in the well, with a rotatively adjustable connection enabling rotation of the tubular conductor to different rotary positions for producing holes in the formation in different directions. A second whipstock may be lowerable into the tubular conductor to direct liners from within the conductor into the holes formed in the formation.

Abstract: A window assembly is provided for use at a downhole location in a first wellbore to control access to or allow isolation of a second wellbore extending from the first wellbore. The window assembly is included as an integral part of a production tubing string disposed within the first wellbore. A slot is formed in the window assembly. The window assembly is preferably installed at a downhole location aligned to an opening from the first wellbore into the second wellbore whereby well tools may move between the longitudinal bore of the window assembly and the second wellbore. Multiple guide surfaces are provided in the slot to direct movement of tools between the longitudinal bore and the window assembly and the second wellbore or vice versa. One of the guide surfaces on the slot preferably is formed with approximately the same angle at which the second wellbore intersects the first wellbore.

Abstract: A sectional drive system for transmitting power linearly or in a curved path to an output, which system includes multiple, tapered and splined, interlocking drive segments which are nested and stacked as a segment string that is rotatable in a selected path. The top one of the segments cooperates with a drive mechanism to effect rotation of the nested segments in concert and the bottom one of the segments connects to a suitable output such as a drill bit. Articulation of the segments with respect to each other due to matching asymmetrical splines and companion spline slots having drive faces and spline support faces of dissimilar size, facilitates dampening of drive vibration and bending of the segment string in or out of the chosen path in any desired direction to facilitate transmitting power in a curved path of desired magnitude from the drive mechanism to the output.

Abstract: A tool for wellbore sidetracking operations has been invented, the tool, in one aspect, having a body, a milling section on the body for milling an opening in a tubular in a first wellbore in a formation, the milling section having milling material thereon, and a drilling section on the body for drilling a second wellbore beyond the window into the formation.

Abstract: A method and apparatus for enhancing production from a well by lowering a tubular conductor into the well to a position in which the conductor extends downwardly from near the surface of the earth to a zone beneath the surface, and advancing a drilling unit past a whipstock held by the tubular conductor at the predetermined zone, and thereby deflecting the drilling unit in a lateral direction through an opening in a side wall of the conductor into the earth formation about the conductor. The whipstock may initially be attached to the drilling unit by a shear connection. An anchor may lock the lower end of the tubular conductor in place in the well, with a rotatively adjustable connection enabling rotation of the tubular conductor to different rotary positions for producing holes in the formation in different directions. A second whipstock may be lowerable into the tubular conductor to direct liners from within the conductor into the holes formed in the formation.

Abstract: Single horizontal wells drilled through heterogeneous reservoirs are capable of greater oil productivity than vertical wells, often with lower produced GOR and WOR. Multiple drainholes tied-in to a vertical cased well are even more beneficial. Completion of such drainholes in many sandy reservoirs must use cemented liners. Well configurations comprising multiple drainholes liners, each of them tied-in to a vertical casing by pressure-tight connections require novel technologies making use of some novel downhole equipment, tools and procedures for drilling, tie-in and completion of such wells. These may be for newly-drilled wells or may be obtained by re-entry into an existing vertical cased well. Specific equipment, including novel casing joints, whipstocks, intermediate liners and tubing completion assembly components applicable to new wells are described herein.

Abstract: Single horizontal wells drilled through heterogeneous reservoirs are capable of greater oil productivity than vertical wells, often with lower produced GOR and WOR. Multiple drainholes tied-in to a vertical cased well are even more beneficial. Completion of such drainholes in many sandy reservoirs must use cemented liners. Well configurations comprising multiple drainholes liners, each of them tied-in to a vertical casing by pressure-tight connections require novel technologies making use of some novel downhole equipment, tools and procedures for drilling, tie-in and completion of such wells. These may be for newly-drilled wells or may be obtained by re-entry into an existing vertical cased well. Specific equipment, including novel casing joints, whipstocks, intermediate liners and tubing completion assembly components applicable to new wells are described herein.