Abstract: This invention provides a bottomhole assembly that contains a thruster for applying an axial force on the drill bit during drilling of the wellbore. The bottomhole assembly includes at least one sensor which provides measurements for determining a parameter of interest relating to the drilling of the wellbore. A power unit supplies power to the thruster to move a member toward the drill bit to apply the force on the drill bit. A processor operatively coupled to the thruster controls the magnitude of the force generated by the thruster in response to one or more parameters interest.

Abstract: An apparatus and method for controlling an underground boring machine during boring or reaming operations. A boring tool is displaced along an underground path while being rotated. In response to variations in underground conditions impacting boring tool progress along the underground path, a control system modifies the rate of boring tool displacement along the underground path while rotating the boring tool at a selected rotation rate to optimize excavation productivity. The controller may also monitor the rate at which liquid is pumped through the borehole and automatically adjust the rate of displacement and/or the liquid flow rate so that sufficient liquid is flowing through the borehole to remove the cuttings and debris generated by the boring tool.

Abstract: A method of controlling rock drilling wherein the cut length changes from a predetermined cut length, the drilling length is changed by transferring the position of the pattern in the longitudinal direction of the tunnel so that the positions of the end points of the holes remain essentially the same with respect to one another, and a collaring surface is crosswise of the tunnel and different from the actual rock surface.

Abstract: A reclamation pipe boring apparatus for sewerage wherein a vehicle body (14) is provided with an outrigger (20) upwardly projecting via the center thereof and actuated by hydraulic pressure, a cutting device (25) disposed in the front region of the vehicle body (14), actuated by hydraulic pressure and having a rotary cutter (24) at the front end, lift means (30) actuated by hydraulic pressure to move the cutting device (25) up and down, reach means (35) actuated by hydraulic pressure to move the cutting device (25) back and forth, and swing means (40) actuated by hydraulic pressure to turn the cutting device (25) clockwise and counterclockwise.

Abstract: An apparatus and method for determining a location and an orientation of an underground boring tool by employment of a radar-like probe and detection technique. The boring tool is provided with a device which generates a specific signature signal in response to a probe signal transmitted from above the ground. Cooperation between the probe signal transmitter at ground level and the signature signal generating device provided at the underground boring tool results in accurate detection of the boring tool location and, if desired, orientation, despite the presence of a large background signal. Precision detection of the boring tool location and orientation enables the operator to accurately locate the boring tool during operation and, if provided with a directional capacity, avoid buried obstacles such as utilities and other hazards. The signature signal produced by the boring tool may be generated either passively or actively, and may be a microwave or an acoustic signal.

Abstract: A system includes a database that is adapted to store substantially continuously measured or calculated drilling parameters. At least one computer can access the database to display simultaneous user configurable graphical representations of selected drilling parameters. A user can observe multiple parameters graphically in real time.

Abstract: In a percussion boring machine having run monitoring a measuring and transmitting unit and an above-ground receiver the pneumatically or hydraulically driven and controlled striking piston (3) reciprocates between the tip of the machine and a rear stop (8). In order to expose the measuring and transmitting unit as little as possible to the influence of the ram blows acting on the tip of the machine, it is arranged so that (when viewed in the direction of advance) it is in front of the rear stop.

Abstract: A method and apparatus for precisely controlling the rotation of a drill string. A sensor monitors the rotation of the drill string and transmits the rotational information to a computer. The computer controls the rotation of the motor driving the drill string and rotates the drill string through an angle input by the operator. The computer may also utilize the sensor's rotational information to oscillate the drill string between two predetermined angles. The computer may also receive orientation information from a downhole tool sensor. The downhole tool information may be combined with the rotational information to enable the computer to accurately reorient the downhole tool.

Abstract: A transponder conduit end cap includes a transponder housing having two flat, generally parallel walls defining a cavity, a transponder located in the housing, and a fitting which attaches the transponder housing to the end of a conduit, to thereby seal the conduit. The transponder axis is maintained in a predetermined orientation (e.g., vertical), such as by partially filling the cavity with a liquid, and using a buoyant envelope to contain the transponder. Alternatively, the vertical orientation may be maintained by pivotally supporting the transponder from a trunnion attached to an interior of the housing. The transponder can be supported by the trunnion using a loop attached to an end of the transponder, the loop being placed about an annular chamfer of the trunnion to allow spherical articulation. The transponder can be active or passive.

Abstract: The invention is a control device or directional drilling tool. The control device has an electromotor drive in the orienting device. The measuring and control device is situated between the orienting device and the drill string. Cable lead-throughs through the orienting device are eliminated. The electromotor drive of the orienting device can be actuated independently of drilling operations, making it possible to perform a rapid and precise performance of an orientation process while continuing drilling operations, reducing deviations from the planned drilling program.

Abstract: A guidance module for an underground horizontal boring assembly. The module determines the pitch angle of the boring tool independent of roll using a single accelerometer sensor. The accelerometer sensor has a single sensitive axis which is aligned parallel to, and preferably coaxial with, the longitudinal axis of the boring tool. The accelerometer sensor is calibrated to obtain a temperature offset and a gain compensating gain factor. Data samples are read from the accelerometer sensor while the boring tool is rotating. The temperature is read from the temperature sensor. The data samples from the accelerometer sensor and the temperature from the temperature sensor are transmitted to a processor. The processor applies simple average filtering to the accelerometer data samples to get an average result, and adjusts the average result for gain. The average result is adjusted for the temperature offset and for the gain compensating gain factor.

Abstract: A borehole drilling system has a well tubing actuator with a well tubing connector on a working end of the well tubing actuator, a transducer responsive to longitudinal movement of the working end of the well tubing actuator and a control system for the well tubing actuator to provide controlled longitudinal movement of the well tubing connector using a selected drilling program and feedback from the transducer. Plural lengths of well tubing are connected to the well tubing connector, with a jet drilling apparatus connected to the downhole end of the well tubing. An underreamer apparatus may be attached to the bottom hole end of the well tubing. Coiled tubing may be attached to the bottom hole end of the well tubing and directed through a whipstock.

Abstract: An apparatus and method for locating an underground object or structure by employment of a radar-like probe and detection technique is disclosed. The underground structure is provided with a device which generates a specific signature signal in response to a probe signal transmitted from above the ground. Cooperative action between the probe signal transmitter at ground level and the signature signal generating device provided on the underground object provides for accurate detection of the subsurface object, despite the presence of a large background noise signal. The depth and, if desired, orientation of the underground object may also be determined using the signature signal generated by the signature signal generating device mounted to the underground object. Orientation information may be encoded on the signature signal or transmitted as an information signal separate from the signature signal. The probe signal may be microwave or acoustic.

Abstract: The invention provides a tractor for locomoting a drilling apparatus. The tractor includes a retractable body for transporting and pressurizing a drill attached to a front drilling end of the retractable body. The retractable body is longitudinally extended and contracted for length adjustment. A drill stabilizer is attached to a rear trailing end of the retractable body. The drill stabilizer is extended to secure said retractable body during drilling and retracted for allowing movement of the rear trailing end of the retractable body. A position stabilizer is attached to the front drilling end of the retractable body. The position stabilizer is transversely extendable against the sidewalls of the drill hole for periodically stabilizing the retractable body. The position stabilizer retracts for operation of the drill when the drill is stabilized with the drill stabilizer.

Abstract: An apparatus and method for locating an underground boring tool using a radar-like probe and detection technique. A boring tool is provided with a device which generates a specific signature signal in response to a probe signal transmitted from above the ground. Cooperative operation between the probe signal transmitter at ground level and a signature signal generator disposed within the boring tool provides for the accurate locating of the boring tool, despite the presence of a large background signal. The signature signal produced by the boring tool may be generated either passively or actively, and in a manner which differs from the probe signal in one or more ways, including timing, frequency content, or polarization. A survey of a boring site, made either prior to or during the boring operation, provides data related to the characteristics of the ground medium subjected to the survey and the identification of underground hazards, such as buried utilities.

Abstract: A method and a system suited for controlling the behavior of a drill bit includes an additional resistant torque added to the torque about the drill bit so that the overall torque about the drill bit is an increasing function of the rotary speed of the bit. The system includes control means suited for creating an additional resistant torque about the bit.

Abstract: A bottom hole drilling assembly connectable to coiled tubing comprises a downhole motor to rotate a drill bit, articulated sub for causing the drill bit to drill a curved bore hole when a second portion thereof is bent from coaxial orientation with a first portion, steering tool for indicating the attitude of the bore hole, thruster for providing force to advance the drill bit, and orientating tool for rotating the thruster relative to the coiled tubing to control the path of the bore hole.

Abstract: The present invention relates to a positioning device capable of positioning a member in any direction with a high degree of resolution by using a hollow type harmonic drive mechanism, and to a drilling-direction control device for a drilling system utilizing the positioning device. The device of the present invention is mainly constituted by a double eccentric mechanism section (10). A first annular member (12) is rotatably supported by a circular inner circumferential surface (11a) of the cylindrical member (11) of this mechanism section, and a second annular member (13) is rotatably supported by a circular inner circumferential surface (11b) of the first annular member.

Abstract: The adjusting device consists of at least one drill string element (40) integral in rotation with the drill string and fastened to the drill string in the vicinity of the drill bit. Element (40) comprises parts (41, 43, 46) whose outer bearing surfaces are arranged in a cylindric surface with substantially the axis (48) of the drill string as the axis and substantially the nominal diameter of hole (4) as the diameter, distributed around the axis so as to generate, during part of the rotation of the drill string, by reaction of the well of hole (4) on element (40) , forces tipping the drill bit out of the drilling plane. Bearing parts (45, 46) may consist partly of variable-diameter mobile blades.

Abstract: An automatic closed loop drilling system is disclosed for providing automatic directional drilling capabilities in a bottomhole assembly. The drilling system includes at least one adjustable stabilizer that varies in response to formational and drilling conditions encountered downhole. A microcontroller is preprogrammed with a desired range of formation characteristics or with a desired inclination or target area. The microcontroller compares actual sensed data with the desired data and adjusts the position of the stabilizer blades to vary the direction of drilling.

Abstract: A drill head for making a hole in the ground, said drill head comprising a mantle (1), a spraying device carrier (3) mounted inside the mantle (1) so it can rotate, a motor (2) installed inside the mantle (1) driving this spraying device carrier (3), at least one spraying device (4) eccentrically mounted on the spraying device carrier (3) and a pipe line (11) for fluid in order to supply fluid to the spraying device (4), characterized in that the spraying device (4) is a turbo-jet.

Abstract: The present method and apparatus are directed to river crossings and the like. A horizontal drilling rig is set up and drills under a body of water or the like. Angular measurement sensors carried at the drill bit provide data periodically which is transmitted from a transmitter at the end of the drill string. Two antennas are deployed, the two being parallel strips spaced equally on the left and right of the right of way. They connect with two receivers. The transmitted angular data is used to determine the location of the drill bit. Progressive determinations of the transmitter enable determination of the trajectory during drilling. The two antennas are used to provide redundant reception of the transmitted signal. In addition to that, a quick reading of lateral drift is obtained by measuring the ratio of the received signals. The two antennas have the form of flat strips which can be deployed across the terrain, over a river, and the like.

Abstract: A flexible steering sub is disclosed for flexible drilling of horizontal wells, geothermal drilling for electric power generation; earth sciences study of and monitoring of earth movement with respect to fault movement; environmental science cleaning up of inaccessible polluted areas; coring to test rock strength prior to large scale constructions such as dams; introduction of chemicals for solution mining, and the like. The flexible sub comprises an elongated housing having a plurality of housing sections connectable at one end to an orientation sub for a PDM drill and connectable at the other end to a wire line connector. An electronics assembly including guidance directional sensors and probe is positioned in a plurality of the housing sections, interconnected electrically, and connected at one end to the wire line connector.

Abstract: An attitude control device has a plurality of harmonic drive mechanisms of the hollow type, preferably first and second harmonic drive mechanisms. First and second rotational members are connected to the outputs of the first and second harmonic drive mechanisms. These rotational members have eccentric hollow portions which rotate eccentrically around the rotational axes of the harmonic drive mechanisms. A member to be driven is placed to extend through the eccentric hollow portions such that it is supportedly contacted with the inner surfaces of the eccentric hollow portions. In operation, the eccentric hollow portions are rotated relative to each other, whereby the member to be driven is controllably oriented to a desired direction.The attitude control device can be employed as a drillingdirection control device wherein a rotational drill shaft is supported by inner surfaces of eccentric hollow portions of first and second rotational members.

Abstract: The invention provides a system for precisely guiding the direction of a drill bit. The drill shaft has an orientation sensor that detects deviation of the drilling direction from the desired direction; the drill bit is steerable by preferentially directing flushing fluid at the drilling end; and a fluid modulation means controls the flushing in response to a signal from the orientation sensor. The invention also provides a tiltmeter for detecting deviation from vertical of the axis of rotation of a rotating shaft. A gravity-driven mechanical oscillator, for instance a pendulum, is carried by the rotating shaft, and has a natural oscillation frequency matched to the rotational frequency of the shaft; and a sensor determines the phase relationship of the oscillator relative to the angular position of the shaft, thereby producing a signal indicating the deviation of the shaft from vertical.

Abstract: An attitude control device has a plurality of harmonic drive mechanisms of the hollow type, preferably first and second harmonic drive mechanisms. First and second rotational members are connected to the outputs of the first and second harmonic drive mechanisms. These rotational members have eccentric hollow portions which rotate eccentrically around the rotational axes of the harmonic drive mechanisms. A member to be driven is placed to extend through the eccentric hollow portions such that it is supportedly contacted with the inner surfaces of the eccentric hollow portions. In operation, the eccentric hollow portions are rotated relative to each other, whereby the member to be driven is controllably oriented to a desired direction.The attitude control device can be employed as a drilling-direction control device wherein a rotational drill shaft is supported by inner surfaces of eccentric hollow portions of first and second rotational members.

Abstract: Hardware, software and methods for controlling the usage of well drill bits and other aspects of well drilling plans. At least a portion of a given well is drilled with a given drill bit. An abrasive-wear-affecting variable (drilling strength) for the lithology which has been most recently drilled with the bit is continually evaluated. The current abrasive wear of the bit by the total lithology which has been drilled thereby is continually calculated, based on the abrasive-wear-affecting variable. Continued use or retirement of the bit is controlled in accord with the wear calculation. Relative pore pressure at the current site of the drill bit is a useful by product which can be independently used to control other aspects of the well drilling plan, e.g. mud weight and the setting of casing.

Abstract: There is disclosed a method and an apparatus for easily controlling the advancing direction of an excavating machine without causing the excavating machine to largely trace in a zigzag way. The direction control is done by the steps of mounting a reflector on a head portion of a shield body so as to receive a light beam directed along an imaginary reference line, mounting a target on a tail portion of the shield body so as to receive the reflected light beam from the reflector, controlling means for correcting the direction so that the reflected light beam may be irradiated at an objective position within the target, and thereby controlling the advancing direction of the excavating machine so that a subjective portion at the front end of the head portion may follow along the reference line.

Abstract: A method for automatically monitoring the vibrational condition of a drill string fitted with detectors comprises the following steps: obtaining a reference spectrum for each detector; obtaining a spectrum for each detector representing the actual situation; comparing the two spectra to detect possible instabilities in the values measured by the detectors; indication of said instabilities by means of audio and/or visual devices.

Abstract: A navigable downhole drilling system incorporating a drilling motor having a system of sensors and information processors for determining the depth, inclination, direction and thrust of the drilling motor. Accordingly, the drilling operation can be continuously monitored and adjusted to ensure desired directional drilling. A programmed processor may be incorporated into the drilling system to guide the drilling motor along a predetermined course. A generator assembly provides power to the processors and sensors as a result of the precessional rotation of the rotor within the stator of the drilling motor. The overall length of the drilling system is minimized by piggybacking the thrust bearings with the power generation unit and siamesing the transmission assembly for the drilling motor with the power section of the motor. As a result, a downhole drilling system of navigable length is created which can be readily directed along the desired course.

Abstract: A steerable burrowing mole including a forward steering unit with an axial main portion, adjustable fins, and apparatus to adjust the fins between first and second angular orientations, the first for inducing mole rotation and the second for inducing movement toward a first radial direction. The earth-penetrating tip is preferably beveled surface to provide maximum turning force toward the first radial direction. One of the fins is in an orientation for inducing slight corrective reverse rotation. An adaptor for converting a basic burrowing mole into a steerable mole as described.

Abstract: Real-time monitoring of a target production zone is followed by an oscillatory drilling path to create a borehole having improved zone drainage capability. Real-time monitoring uses geophones placed in adjacent wells or the well being drilled. The drilling process itself generates the seismic signals. When the geophones are located in the well being drilled, the seismic signals are transmitted from downhole to surface through intermittent pressurization of drilling mud. Once drilling penetrates the zone, the oscillatory path is followed by fracturing to improve fluid drainage paths and minimize additional drilling.

Abstract: A rotary boring machine comprises a base machine placed on the ground, a boring drill provided with the base machine and driven for rotation, a dip gauge provided at the tip end of the boring drill, a first circuit provided in an intermediate portion of the boring drill and electrically connected to the dip gauge for producing a varying flux corresponding to the output signal of the dip gauge, and a second circuit provided in the intermediate portion of the boring drill in opposition to the first circuit and inducting an induction current corresponding to the output signal of the dip gauge through an electromagnetic induction caused by the varying flux generated by the first circuit. The output signal of the dip gauge is transmitted by electromagnetic induction between the first and second circuits and thus transmitted to the base machine without requiring physical connection of the signal transmission lines.

Abstract: According to the present invention, there is disclosed an apparatus for controlling the direction of displacement of an underground excavator including a turnable jack to perform excavating operations in the underground region while controlling the direction of the same by turnably displacing a pilot jack, wherein a quantity of turnable actuation of the turnable jack in the vertical direction is determined by employing a fuzzy presumptive theory having two inputs and one output used therefor under conditions that a corrected pitching angle and a steering sensibility sensible in the vertical direction are taken as inputs and a quantity of turnable actuation of the turnable jack in the vertical direction is taken as an output, while a quantity of turnable actuation of the turnable jack in the horizontal direction is determined by employing the presumptive theory having two inputs and one output used therefor under conditions that a corrected yawing angle and a steering sensibility sensible in the horizontal dir

Abstract: The present invention provides an apparatus for orienting a drilling tool in a borehole, and which employs drilling mud pressure to selectively hydraulically move force-transmitting elements associated with pressure members on the exterior of the tool against the wall of the borehole, or to radially shift the drive shaft of the drilling tool in the tool casing. The tool may also include a drilling mud powered centering mechanism for maintaining the tool or the drive shaft within the tool in a centered basic position. A tool may include both pressure members and a shiftable drive shaft, as well as centering mechanisms to act on both the pressure members and the drive shaft.

Abstract: The present invention discloses a drilling tool apparatus and method for sinking drill holes in underground rock formations while using a selectable direction profile for the drill hole.

Abstract: Steerable ground drilling device, which comprises a body (3) destined to be attached to a flexible pipe, a rotatable head (4) which is mounted on the front extremity of the body (3) and is provided with at least one spraying device or hammer drill (5) to which fluid under pressure can be supplied through a pipe (10 through 13) which extends through the head (4) and the body (3), and means (6) for rotating the head (4), characterized in that the means (6) for rotating the head (4) are means which can rotate this head (4) both in one direction and in the other direction and that, between the head (4) and the body (3), an axially located shaft section (7) is mounted that is attached to the head (4) and through which extends the pipe (10 through 13) for the supply of fluid under pressure to the spraying device (5), a cylinder (14) which surrounds the shaft section (7) and comprises an outer periphery which is eccentric in relation to the shaft section (7), and a blocking mechanism (15) is mounted that can couple

Abstract: An earth boring apparatus is illustrated including an engine and an earth boring string wherein a hydraulic clutch driven by the engine is supplied with hydraulic fluid through an electrically operated valve controlled by a manually operated trigger so that release of the trigger resulting from a torque as may be occasioned by encountering a rock or other obstruction interrupts manual operation of the trigger disabling the clutch.

Abstract: An earth drilling apparatus has a pneumatic motor operated earth drilling tool, a valve assembly connected to the motor, and a drill string connected to the valve and to a source of pneumatic fluid. The drilling tool has an earth drilling bit and a rotor/stator motor section to apply a rotational force to rotate the bit at the bottom of the string. The valve assembly is disposed between the drilling tool motor and the source of pneumatic fluid and controls the flow of pneumatic fluid to the tool. The valve assembly has a pneumatic pressure-operated valve which is operable in response to the pressure of pneumatic fluid in the drill string to be opened to permit flow of pneumatic fluid to the tool at a predetermined operating pressure to transmit an initial pulse of pneumatic fluid to initiate operation of the motor. The valve is kept open at a lower pressure than that required to open it.

Abstract: A process and device making possible the guidance of the drilling tool through geological formations including an analytical device for directional geological analysis that carries out measurements as the drilling advances for guiding the drilling tool through the geological formation. The drilling column at its lower end includes the drilling tool (1) driven by a turbine (2) mounted on an elbow (4), a directional analytical device (3) that carries out measurements according to well set directions, a logging sensor (5), a drilling sensor (6) and a topographic probe (7). When drilling through specific geological formations, the information provided by the directional analytical device (3) is used for guiding the drilling tool in real time.

Abstract: A technique for providing a continuous underground tunnel between first and second spaced-apart points and for installing new cable, pipe or conduit is disclosed herein. This technique utilizes a boring device including means for boring through soil and a thrust conduit which pushes the boring device through the soil from a first starting point to a second end point as the device bores through the soil, whereby to form a tunnel between the two points. Thereafter, the cable to be installed within the tunnel is attached to the front end of the boring device and the latter is pulled back through the tunnel to its starting point by means of the thrust cable, thereby automatically pulling the new cable in place.

Abstract: The homing technique for directing an in-ground boring device through the ground from its particular location to a specific target point is disclosed herein. In accordance with this technique, an electromagnetic dipole field containing a predetermined homing signal is generated at the boring device and detected by a specifically configured receiving antenna arrangement at the target point or, in a preferred embodiment where the target point is below ground, at a ground level point directly above or beyond the target point. Means are provided in response to detection of the homing signal for producing an internal electrical signal containing certain information relating to the actual path taken by the boring device as compared to the path or course leading to the target point. The information from this latter signal is then transmitted by means of electromagnetic waves to a remote location where it is used to steer the boring device on a course toward the target.

Abstract: A method and system for tracking a borehole by means of a probe and an externally produced magnetic field. The magnetic field is produced by a current configuration which facilitates the calculation of the magnitude and direction of the magnetic field at any point in space. In order to locate the probe, magnetometers within the probe are used to measure the magnetic field. Accelerometers within the probe allow the determination of the probe's orientation which enables the measured field vector to be compared to the calculated field vector and the probe's location thereby ascertained.

Abstract: A technique for providing a continuous underground tunnel between first and second spaced-apart points and for installing new cable, pipe or conduit is disclosed herein. This technique utilizes a boring device including means for boring through soil and a thrust conduit which pushes the boring device through the soil from a first starting point to a second end point as the device bores through the soil, whereby to form a tunnel between the two points. Thereafter, the cable to be installed within the tunnel is attached to the front end of the boring device and the latter is pulled back through the tunnel to its starting point by means of the thrust cable, thereby automatically pulling the new cable in place.

Abstract: A system for directional drilling and related method of use is described herein which utilizes a drillstring suspended within a wellbore with an MWD and downhole turbine or motor connected adjacent a drill bit on a lower end of the drillstring, and with a top drive and/or rotary table connected adjacent an upper end of the drillstring. Within the method, desired limits of drilling associated parameters are inputted into a memory associated with a programmable digital computer. While drilling the wellbore, transmitted values of the drilling associated parameters are inputted into the memory. If the transmitted values are outsude of the desired limits, necessary adjustments are calculated and then made to weight-on-bit (WOB), RPM and/or drillstring azimuthal orientation to bring the transmitted values within the desired limits.

Abstract: An earth boring apparatus has a pneumatically operated earth boring tool, a flexible conduit or drill pipe connected to the tool and to a source of pneumatic fluid. The tool has an earth boring member and a reciprocally movable hammer positioned in the tool to apply a percussive force. A valve assembly in the flexible conduit or drill pipe substantially adjacent to the tool between the tool and the source of pneumatic fluid controls the flow of pneumatic fluid to the tool. The valve assembly has a pneumatic pressure-operated valve which is operable in response to the pressure of pneumatic fluid in the flexible conduit or drill pipe to be opened to permit flow of pneumatic fluid to the tool at a predetermined operating pressure to transmit an initial pulse of pneumatic fluid to initiate operation of the hammer. The valve is kept open at a lower pressure than that required to open it.

Abstract: The invention relates to a drilling system. It includes, in combination, a drilling derrick by means of which a string of drill rods can be suspended from a hoist, a motorized drilling head at the end of the hoist, means for bringing a drill rod into position to be added to the drill string from a stack, a motor to drive the hoist, a reversible control for the said hoist motor, sensors for determining the state of the system, and a programmable robot to supply the set points to the hoist motor control according to signals furnished by the said system state sensors.

Abstract: A technique for providing a continuous underground tunnel between first and second spaced-apart points and for installing new cable, pipe or conduit is disclosed herein. This technique utilizes a boring device including means for boring through soil and a thrust conduit which pushes the boring device through the soil from a first starting point to a second end point as the device bores through the soil, whereby to form a tunnel between the two points. Thereafter, the cable to be installed within the tunnel is attached to the front end of the boring device and the latter is pulled back through the tunnel to its starting point by means of the thrust cable, thereby automatically pulling the new cable in place.

Abstract: The methods disclosed herein incorporate the basic concepts and methodologies of a new general rock-bit interaction model useful in predicting and controlling drilling trajectories in directional (and deep vertical) wells. It accounts for the anisotropic drilling characteristics of both the formation and the bit. The model is developed in a 3-D geometry. Therefore, it is capable of predicting the walk tendency and the build-drop tendency of a given BHA (bottomhole assembly) under any drilling condition. The model can be used in the forward mode to predict the drilling direction; in the inverse mode to generate the rock and bit anisotrophy indices; and in the log-generation mode to generate drilling logs, such as a drilling dip log.

Abstract: A control apparatus preferably for concurrently protecting a downhole fluid pressure operated device from excessive fluid pressures and indicating at the surface when any such excessive fluid pressure level has been reached. The pressured fluid is directed through a bore of a sleeve, and a flow plug is normally located in an axially remote position relative to the sleeve bore. The flow plug is moved upon the occurrence of a predetermined fluid pressure across the downhole device to move into the bore of the sleeve and produce a flow constriction which will result in an detectable fluid pressure signal at the surface. Concurrently, a bypass flow path is established around the fluid pressure operated device to immediately reduce the fluid pressure being applied to such device.