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 driving segments which are nested and stacked as a segment string that is rotatable in a guide 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 facilitates dampening of drive vibration and bending of the segment string in the guide 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 retrieval tool for whipstocks is disclosed. A latch is retractable into the tool upon application of hydraulic pressure. A locking pin securely fastens the whipstock and retrieving tool together. The hydraulic pressure acts a cleaning force on the top of the whipstock and the retrieving slot to facilitate engagement. The offset stabilizer, when oriented opposite the lug on the retrieving tool, creates a force in the direction of the lug, whereby latching the retrieving tool will start. A joint of drillpipe or heavyweight drillpipe is run above the eccentric stabilizer. An offset stabilizer is provided to ensure proper initial orientation and avoid sticking the tool. The latch can firmly grip lugs within a slot in the whipstock. A overshot design is also disclosed using a similar hydraulically actuated latch assembly where the latch grabs the whipstock without having to use an opening therein, if for any reason the opening has been fouled with debris or damaged due to milling.

Abstract: A method and apparatus are provided for drilling multiple offshore wells from a single conductor casing string. A guide member is provided for securing to a standard casing string, and running downhole and setting within a lower section of the conductor string. The guide member includes multiple guide bores through which standard casing strings are run. A first one of the standard casing strings i secured into one of the multiple guide bores for lowering the guide member into the lower section of the conductor string. A multibore low pressure wellhead housing is mounted to the conductor string as the guide member is being lowered downhole within the conductor string. Once the guide member is set, the first one of the standard casing strings is released from the guide member and passed downward through the guide member for receiving a drill string and guiding the drill string in drilling a first one of the multiple offshore wells.

Abstract: A method and apparatus for forming a window in well casing. First, using coiled tubing, a two stage whipstock is set in the well casing through the production tubing. Next, a jointed milling assembly is inserted through the production tubing, also using the coiled tubing. The travel of the mill is guided by the two stage guide surface of the whipstock, and the joint in the milling tool allows the direction of the mill to change. Thus, the mill impinges on the well casing at a relatively acute angle to the longitudinal axis of the casing reducing the likelihood that the mill will bite into the guide surface of the whipstock instead of the well casing.

Abstract: A casing is provided with a sealable shifting sleeve. A whipstock is insertable into the casing and may be supported off of the casing in a predetermined location so that it is oriented toward an open window in the casing when the shifting sleeve is selectively moved upwardly. By presenting an open window for the whipstock oriented toward the window, a drillbit may be lowered through the casing to interact with the whipstock to immediately begin the drilling of the deviated wellbore. The drillbit cuts through any cement, if present, and into the formation. A bore is presented in the whipstock to allow production from pay zones below the whipstock while it is in place. Should it become necessary, the sliding sleeve may be subsequently closed to isolate the deviated wellbore which has been drilled with the whipstock through the open window.

Abstract: A method and system for lateral drilling with respect to a main well which is cased by a casing string. At least a part of the casing string provides a lateral opening adapted to enable drilling of a lateral well. A guiding device is positioned at a part of the casing string in front of the lateral opening and the guiding device is controlled from the surface of the main well. A lateral casing string equips the lateral well and provided a sub for connecting the lateral casing string to the main string in the main well.

Abstract: A sidetrack mill is provided for drilling through a cased borehole to provide a sidetracked wellbore having a final diameter, the mill comprising: a pilot mill having a tapered cutting surface being, at its largest diameter, between about 50% and about 75% of the final diameter; a second stage cutting surface being, at its smallest diameter about the diameter of the maximum diameter of the pilot mill, and being at its largest diameter, at least five percent greater in diameter than the largest diameter of the pilot mill; and a final stage cutting surface being, at its largest diameter, about the final diameter, and at the smallest cutting surface diameter, being a diameter of at least about 5% smaller than the final diameter. This mill is can rapidly penetrated casings without requiring excessive torque. The milling can be accomplished with a single trip.

Abstract: A kick-off device is provided. The kick-off device is useful in drilling a pair of opposite deviated borehole branches in an under ground formation from a single borehole and comprises an open-ended tube provided at its upper end with connecting means to join the open-ended tube to a string of casing, and a guide element arranged in the open-ended tube near its lower end, which guide element includes two hollow slanted guide ways arranged on opposite sides of the guide element, wherein the wall of the open-ended tube has elongated openings facing the slanted guide ways.

Abstract: A drilling head for making a borehole along a predetermined underground path is formed by a tubular body having a guidable rotary drilling sub normally axially mounted in the body by means of a sleeve bearing journalling a drill bit equipped rotary drilling string sub joint moveable with and within the sleeve for disposing the drilling bit on a predetermined angle in a predetermined direction relative to the longitudinal axis of the body by means of diametrically opposite superposed pairs of wedges interposed between respective end portions of the sleeve bearing and the inner periphery of the body.

Abstract: A scoophead/diverter system is run into a wellbore using a novel scoophead running tool. The running tool allows circulation through its inside diameter, and has internal pressure integrity to test any seals below the running tool prior to releasing the scoophead. This also allows circulation while running in order to apply MWD techniques. This run-in tool includes a mounting head from which extends a running stump and a housing (or connecting mandrel) parallel to the running stump. The running stump and housing are sized and configured to be respectively received in large and small diameter bores in the scoophead. The scoophead running tool thus allows torque to be transmitted about the centerline of the scoophead assembly in spite of being attached into one of the offset bore. This torque transmission is accomplished by connecting the connecting mandrel between the running tool and scoophead at the same offset as the large bore of the scoophead.

Abstract: An extendable, retractable, erectable arm assembly for housing and supporting a water conduit extending outward from a tool located in a borehole, to a nozzle to produce a high pressure water cutting jet is provided. The arm assembly includes a plurality of interlocking arm segments for housing, supporting and moving the conduit through an angle of about 90.degree. from a stowed position to an operating position. The arm segments include integral, separable hinges capable of being interlocked such that pivotable movement is possible along any side thereof. These segments have mating apertures therethrough to accommodate the conduit. The assembly also includes an erecting device which provides compression on the segments and which gives the arm rigidity during movements. An alignment device is also included which keeps the segments aligned when the arm is deflected.

Abstract: Apparatus for drilling horizontal drain holes from within existing wellbores is comprised of a flexible rotary drillstring made from a plurality of arcuate elements tightly drawn along a central cable, and of driving and redirecting apparatus to rotate and deflect the drillstring. The elements, engaged to the cable, provide a stiff drillstring which, combined with the rotary drive at the well bottom, permits extensive drilling. A deflection block, precisely fitted to the drillstring and to other apparatus requirements, enables the drilling functions. An alternate drillstring has cylindrical interlocking elements with internal alignment means.

Abstract: A flexible drill string for curving a vertical borehole laterally towards the horizontal, comprising an elongated flexible casing made of a plurality of sections with each section having a longitudinal central axis. Each section is attached to an adjacent section such that the casing string can conform to a segment of a curve. An elongated flexible drilling string is rotatably received within the flexible casing and an annulus is formed between the casing and drill string. The drill string has a central fluid passageway of resilient material surrounded by a plurality of longitudinally extending bendable members that jointly encapsulate the central fluid passageway and forms an outer housing about the drill string. The drill string central passageway is an elastomeric conduit and the plurality of bendable members are placed circumferentially thereabout and are connected together to form the housing.

Abstract: A well casing penetrator includes an elongated housing having a work fluid input chamber and enclosing an outwardly movable hydraulic cylinder driven punch for cutting an opening in a casing. A high pressure liquid jet nozzle is mounted on the end of a lance-like hose having a nozzle on its outer end which is moved outwardly or inwardly through an axial bore in the punch by a lance drive piston and cylinder assembly with outward movement serving to cut a radially extending opening in the surrounding earth. A moveable valve spool is connected to a coil compression spring which urges the spool toward a first position in the spool directs work fluid to hydraulic punch cylinder and lance drive piston and cylinder assembly so that the punch and lance-like hose are maintained in retracted position.

Abstract: A device for drilling lateral boreholes from a cased parent well comprises selecting and coupling means adapted to cooperate with a deflection unit placed within the parent well. The selecting and coupling means are mounted at the lower end of an extension unit formed by interassembled tubular elements. The upper end of the extension unit is rigidly fixed to a suspension swivel within the wellhead and at least one slip joint is interposed between two tubular elements. The internal diameter of each tubular element is such that a drilling packer can be housed within the tubular elements.

Abstract: A well casing penetrator includes an elongated housing enclosing an outwardly movable hydraulic cylinder driven punch for cutting an opening in a casing. A high pressure liquid jet nozzle is mounted on the end of a hose which moves outwardly through an axial bore in the punch when extended through the casing to cut a radially extending opening in the surrounding earth. The punch includes arcuately curved longitudinal slots along opposite sides which cause tabs to be bent back along opposite sides of the opening cut in the casing to prevent dislodging of any portion of the casing from the casing as a consequence of the operation of the punch. A spool piston is connected to a single accumulator that is pressurized to urge the spool piston toward a first position in which work fluid controlled by the spool piston retracts the hydraulic punch cylinder and a hose drive cylinder for moving the hose in the punch.

Abstract: A bit assembly for undercutting a blind bore extending along a bore axis between an open outer end and a closed inner end and having a substantially cylindrical wall of a predetermned diameter centered on the bore axis and extending between the ends comprises a pusher body normally seated in the closed inner end of the bore and having an outwardly turned camming surface inclined to the bore axis, and a bit having a shaft extending along a longitudinal bit axis and having an inner end, an outer end, and a pair of longitudinally extending sides terminating at the inner end. One of the sides is at least partially cylindrical and centered on the bit axis and the inner end is formed with a camming surface engageable with the camming surface of the body and inclined to the bit axis. A blade fixed permanently and stationarily on the inner end projects radially from the one side of the shaft, the other side being cut back toward the bit axis.

Abstract: A well casing penetrator includes an elongated housing enclosing an outwardly movable hydraulic driven punch for cutting an opening in a casing. A high pressure liquid jet nozzle is mounted on the end of a hose which moves outwardly through an axial bore in the punch when extended through the casing to cut a radially extending opening in the surrounding earth. The punch includes longitudinal slots along opposite sides which cause tabs to be bent back along opposite sides of the opening cut in the casing to prevent dislodging of any portion of the casing from the casing as a consequence of the operation of the punch.

Abstract: Difficulties are encountered in mining in making shot-firing boreholes from a narrow cross-heading into the lateral walls at right angles to the length of the cross-heading. The invention provides for this purpose a drilling unit with a flexible drilling shaft (5) formed by a steel spiral, which is brought up in the direction (7) of the cross-heading and is deviated within the unit substantially at right angles into the direction (10) of the borehole. The deviating station (3) provided for this purpose comprises, in a preferred embodiment, a turntable (11) fitted with pairs of rollers (12), which absorbs the substantial feed forces and reduces the wear on the flexible drilling shaft (5). The circulation fluid necessary for the drilling is conveyed through a pressure hose extending within the flexible shaft (5), which is connected pressure-tightly to the ends of the flexible shaft by means of special screw fittings.

Abstract: Drilling apparatus is disclosed adapted for drilling upwardly a deviated hole from a carriage assembly disposed in a cased vertical hole below a target zone of a hydrocarbon bearing formation. The drilling apparatus includes a drill motor assembly having a drill bit driven by a shaft of a drill bit mud pressure driven motor. A weight on bit assembly is provided below the drill bit motor for imparting "weight-on-bit" drilling force to the drilling bit against the face of the borehole. The weight on bit assembly includes an anti-rotation assembly for preventing rotation of the drill bit motor with respect to the borehole and an axial drive assembly for applying axial force to the drill bit. Apparatus is provided to reverse the direction of the axial force generated by the weight on bit assembly. Apparatus is also provided to limit the axial force applied to the drill bit to a predetermined level.

Abstract: A reamer apparatus is adapted for use in combination with a radial whipstock assembly in drilling a curved bore in a subsurface formation at a predetermined angle of build. The reamer apparatus is comprised of a drill bit, at least one articulated joint or drill collar connected to the lower end of the drill string, and a stabilized reamer interconnected for rotation behind the drill bit which includes cutter blades overgauged in relation to the drill bit and projecting substantially in outward radial directions from the reamer body, each blade having an elongated cutting edge which extends substantially parallel to the direction of drilling and a stabilized leading end so as to stabilize the reamer and avoid preferential cutting as the drill bit proceeds along the desired course.

Abstract: A method of drilling and completing multiple branch wells extending from a main generally vertical hole. This invention finds its primary applicability in in situ leach mining of deep (500 to several thousand feet) lying ore bodies such as uranium, copper, etc. Initially, the main generally vertical hole is drilled, cased, and cemented. Whipstock drilling guides are placed to extend downwardly and outwardly from the bottom of the casing for this hole and cemented in place. These guides are the same in number as the branch holes to be drilled. In addition, the well bore casing contains an indexing dog just above the whipstock drilling guide. The actual drilling of the branch wells is accomplished with a floating index collar and a drill bit assembly which runs therewith. The indexing dog is fixed in the main hole and engages the indexing collar so that the drill bit is oriented to drill into one of the whipstock drilling guides.

Abstract: This invention is directed to a method and apparatus for drilling horizontal holes in geological strata from a vertical position. The geological structures intended to be penetrated in this fashion are coal seams, as for in situ gasification or methane drainage, or in oil-bearing strata for increasing the flow rate from a pre-existing well. Other possible uses for this device might be for use in the leaching of uranium ore from underground deposits or for introducing horizontal channels for water and steam injections.

Abstract: A method and apparatus for deviating a conductor casing, or the like, after it has been driven into a substratum, generally beneath the floor of a body of water. The conductor casing is characterized by a drive shoe assembly on the end thereof having a bevel cut extending therethrough for up to 180 degrees of the circumference thereof, or more, and thereby providing a residual connection characterized as a hinge means. The conductor casing and drive shoe is characterized in operation by an entire linear configuration until they are driven beneath the floor into the substratum, at which time the hinge means allows closure of the distal end through the arc of the bevel cut thereby providing a deviated section which produces directional implacement of the conductor casing.

Abstract: A device for facilitating directional drilling of small diameter holes radially of a mine long hole comprising a segmented sleeve for movement through a guide channel in a main drill unit. A small bit is driven by a flexible shaft which passes through the segmented sleeve. The segmented sleeve remains partially in the guide channel and extends partially out of the guide channel in a straight line from the guide channel. The segments are joined in a manner permitting a 90.degree. turn in the guide channel but allowing no curvature in the portion of the segmented sleeve extending from the guide channel.