Abstract: Boring apparatus for drilling laser guided microbore tunnels uses a liquid stream to remove soil as slurry and an airstream to conduct the slurry away from the bore head. The cylindrical head houses a drill shaft steered by a pair of remotely controlled rams according to the position of a laser spot on a target fixed close to the end of the drill shaft. Small arcuate steering movements shift the cutter up and down through a first ram alongside the shaft working through a linkage. Side to side steering is provided by a second ram acting directly on the shaft. The components are mounted on an axial base wall which gives repair access and camera view of the target. A drilling platform has rams for advancing the cylindrical head.

Abstract: A method for determining a track of a geographical trajectory which has predetermined start and locations. A data collection device, which has onboard synchronized sensors, is moved between the start and end locations, and physical measurement data such as pitch, heading, roll and distance, is obtained and stored. Thereafter, the stored data is retrieved and mapped to determine error compensation. The physical measurement data, after error compensation, is used to determine the pitch profile, heading profile, distance profile and roll profile to ascertain the geographical trajectory track.

Abstract: A method for forming a subsurface wellbore is disclosed. The method includes operating a drilling string in a first direction of rotation. A first motor located near the end of the drilling string is operated in a direction of rotation opposite that of the drilling string. A drill bit is rotated using a second motor that is coupled to the first motor.

Abstract: In one aspect of the present invention, a downhole drill string assembly comprises a bore there through to receive drilling fluid. A turbine may be disposed within the bore and exposed to the drilling fluid. At least one flow guide may be disposed within the bore and exposed to the drilling fluid wherein the flow guide acts to redirect the flow of the drilling fluid across the turbine. The flow guide may be adjusted by an actuator. Adjustments to the flow guide may be controlled by a downhole telemetry system, a processing unit, a control loop, or any combination thereof. In various embodiments the turbine may comprise rotatable turbine blades.

Abstract: An apparatus for controlling a vibration of a drill string, the apparatus including: a plurality of sensors in operable communication with the drill string; and a controller in operable communication with the plurality of sensors, the controller connectable to a drill string motivator and capable of outputting a signal to the drill string motivator to control the vibration of the drill string.

Abstract: A method for determining a rate of change of longitudinal direction of a subterranean borehole includes positioning a downhole tool in a borehole, the tool including first and second longitudinally spaced surveying devices disposed thereon. The method further includes causing the surveying devices to measure longitudinal directions of the borehole at first and second longitudinal positions and processing the longitudinal directions of the borehole to determine the rate of change of longitudinal direction of the borehole between the first and second positions. The method may further include processing the measured rate of change of longitudinal direction of the borehole and a predetermined rate of change of longitudinal direction to control the direction of drilling of the subterranean borehole. Exemplary embodiments of this invention tend to minimize the need for communication between a drilling operator and the bottom hole assembly, thereby advantageously preserving downhole communication bandwidth.

Abstract: A method of running a tubular string into a wellbore comprises running a bore-lining tubular string into a wellbore substantially without rotation, while rotating a cutting structure at a distal leading end of the tubular string. Other methods provide for rotation of the string and the provision of a non-rotating stabiliser towards the leading end of the string.

Abstract: A method for hydraulically controlling the direction of a drill bit or bottom hole assembly containing a drill contains lateral orifices which can be selectively opened and closed to move a portion of drilling fluid from the drill string out into a narrow gap between the lateral orifices and a lateral bore hole face or wall, which produces a lateral hydraulic force to thereby push the drill bit or bottom hole assembly in an opposite direction of the fluid flow through the lateral orifices. The apparatus for accomplishing this hydraulic steering can provide for the movement of the tip of the orifice into close proximity with the bore hole face to thereby increase the lateral hydraulic force created. This method can also be adapted to push-the-bit bore hole pads to minimize their contact with the bore hole while increasing the lateral force obtained by their engagement.

Abstract: A system for monitoring deflection of a downhole tool assembly. The system comprises a beam source directing a beam at a receptor positioned proximate the downhole tool assembly. The receptor detects the position of incidence of the beam at the receptor. A processor receives signals from the receptor and determines angular deflection of the downhole tool assembly based on incidence of the beam at the receptor. Information from other orientation sensors is also used to determine magnitude and direction of deflection. Deflection information is used by an operator or a control system to maintain or correct the course of the downhole tool assembly.

Abstract: A downhole motor assembly for driving a drill bit. The assembly includes a hydraulic drive section with a stator and a rotor located inside the stator to form a flow path between the stator and the rotor. Fluid flowing through the flow path in response to a pressure differential across the hydraulic drive section creates an operative force to rotate the drill bit. The assembly also includes a regulation mechanism that includes a valve and a fluid flow diversion bore for diverting at least some fluid from the flow path when the pressure differential across the hydraulic drive section is greater than or equal to a transition pressure differential.

Abstract: A micro tunnelling machine has a tunnelling head with a boring bit which is forced in a horizontal direction by a hydraulic thruster. The direction of the head is laser guided. The beam strikes a target in the head and a camera relays an image of the target to an operator located at the tunnel entrance. The operator adjusts the direction by admitting water and draining water from a pair of rams inside the head which move the boring bit up and down or left and right. Water is introduced into the boring bit through the drive shaft of the boring bit. The water forms a slurry which is extracted by a vacuum pipe which enters the slurry as droplets and particles and conducts them away from the tunnelling head.

Abstract: Methods and apparatus for using a quill to steer a hydraulic motor when elongating a wellbore in a direction having a horizontal component, wherein the quill and the hydraulic motor are coupled to opposing ends of a drill string, by monitoring an actual toolface orientation of a tool driven by the hydraulic motor via monitoring a drilling operation parameter indicative of a difference between the actual toolface orientation and a desired toolface orientation, and then adjusting a position of the quill by an amount that is dependent upon the monitored drilling operation parameter.

Abstract: A control system for controlling at least one function of an item of construction equipment. The control system includes a pump, a proportional control valve, a directional control valve, a signal source, a switch, and a processor. The proportional control valve is in fluid communication with the pump and the directional control valve is in fluid communication with the proportional control valve. The switch is adapted to be in an open position and in a closed position. The processor is adapted to receive a processor input, receive the signal from the signal source, and transmit a processor output to the proportional control valve. The switch transmits a false signal to the processor when it is in the open position and a true signal when it is in the closed position. The control system is adapted to control the at least one function of the item of construction equipment.

Abstract: The invention relates to a control apparatus for controlling a rock-drilling rig performing a multiphase rock-drilling event. The control apparatus is arranged to display a working phase indicator on a display, and rock drilling phase-specific information elements is associated with different working phases. The control apparatus is arranged to specify the phase of the rock-drilling event and to update the working phase indicator to display at least one display information element in accordance with the specified working phase.

Abstract: A boring tool moves having a pitch orientation, a yaw orientation and a roll orientation and is steerable underground using the roll orientation. A maximum drill string curvature is established for steering. The boring tool is advanced over a path segment. An averaged roll characteristic is determined for movement of the boring tool along the path segment. A path segment pitch orientation is established based on at least one measured pitch orientation along the path segment. Using the maximum drill string curvature in combination with the averaged roll characteristic and the path segment pitch orientation, the yaw orientation is determined. The averaged roll characteristic is determined based on a series of incremental roll measurements that are spaced across the path segment. A set of coupled ordinary differential equations is used to characterize movement of the boring tool.

Abstract: Aspects of this invention include a steering tool having a controller configured to provide closed-loop control of hydraulic fluid pressure. In one exemplary embodiment, closed-loop control of a system (reservoir) pressure may be provided. In another embodiment, closed-loop control of a blade pressure may be provided while the blade remains substantially locked at a predetermined position. Other exemplary embodiments may incorporate rule-based-intelligence such that pressure control thresholds may be determined based on various measured and/or predetermined downhole parameters. The invention tends to reduce the friction (drag) between the blades and the borehole wall and thereby also tends to improve drilling rates. Moreover, the invention also tends to improve the service life and reliability of downhole steering tools.

Abstract: An electric horizontal directional drilling machine. An electric horizontal directional drilling machine is powered by an electric power assembly. The power assembly is made up of a fuel cell and inverter, or multiple fuel cells with synchronized inverters, are used to power an electric motor controller and electric motor. The electric motor operates hydraulic pumps used to advance a drill string and downhole tool through the earth and operate various machine functions. Mechanical functions of the drilling machine may also be satisfied through the use of electric rotary actuators (e.g., motors) and linear actuators (e.g., linear motors and solenoids).

Abstract: A system and method is provided for drilling a wellbore including a rotary drill bit with a bit body having a plurality of mechanical cutters to cut away formation material as the wellbore is formed; and a directed energy mechanism to direct energy into the formation such that energy from the directed energy mechanism causes fracturing of surrounding material to facilitate drilling in the direction of the directed energy.

Abstract: A method for positioning a rock drilling rig to a drilling site and a rock drilling rig. In positioning the rock drilling rig is driven to the positioning station such that its carrier is at desired distances from wall surfaces surrounding the drilling site. For positioning the rig is provided with distance measuring devices. Navigation is not started until positioning has been performed and in navigation the location of the rock drilling rig is linked to the coordinate system of the drilling site.

Abstract: Methods and systems for controlling movement of a bit of a drilling assembly during reaming of an already-drilled hole; the methods, in certain aspects, including determining a ream speed for downward movement of the bit in the hole, moving the bit downward in a hole at the ream speed, determining a time period for deceleration of the bit to the hole bottom, determining a value for a target drilling parameter for drilling beyond the bottom of the hole, decelerating the bit (linearly or non-linearly) for the time period, and achieving the value for the target drilling parameter when the bit reaches the bottom of the hole.

Abstract: An apparatus is provided for maintaining control of a machine which produces thrust, rotation or other outputs in response to input signals. The apparatus has two distinct parts, namely the operator input portion and the output portion. The operator input portion consists of the primary thrust, rotation and other output control, and the input signal generation, signal maintenance and signal resume control. Through these controls, the operator enters the desired operation at conditions and levels for rotation, thrust, and other input signals. The output portion consists of an information processing and control portion and the power units for rotation, thrust and other outputs generated from the machine. The information processing and control system interprets all of the desired operational conditions and levels from the input portion and sends commands to the thrust, rotation and other power units to produce the desired outputs in response to the input signals.

Abstract: System and method of controlling a trajectory of a wellbore comprises conveying a drilling assembly in the wellbore by a rotatable tubular member. The drilling assembly includes a drill bit at an end thereof that is rotatable by a drilling motor carried by the drilling assembly. The drilling assembly has a first adjustable stabilizer and an second stabilizer spaced apart from the first adjustable stabilizer. The first adjustable stabilizer having set of ribs spaced around the stabilizer, with each rib being independently radially extendable. The position of a first center of the first adjustable stabilizer is adjusted in the wellbore relative to a second center of the second stabilizer in the wellbore for controlling the trajectory of the wellbore.

Abstract: A system for selectively orienting a bit at the end of a drillstring in a wellbore, the system, in certain aspects, having: motive apparatus for rotating a drillstring and a bit connected to an end of the drillstring; a control member manually movable to effect a change in orientation of the bit; a control system in communication with the motive apparatus and the control member for translating a signal from the control member indicative of manual movement of the control member into a command to the motive apparatus, the command commanding the motive apparatus to rotate the drillstring and the bit in correspondence to the movement of the control member.

Abstract: A method and system for fluid characterization in an underground formation surrounding a borehole are provided. Acoustic signals are transmitted and received in the borehole. The received acoustic signals are processed to obtain at least one attribute of formation mobility. Formation fluid is characterized based on a change of the at least one attribute. A decision is made based on the characterization output.

Abstract: A method and apparatus for remotely controlling a machine. A remote operator controls a tracking device including a signal system for selectively emitting a remote enable signal. The remote enable signal is relayed to a control system for the machine. The control system is proximate to the machine and is adapted to enable at least one action of the machine upon detecting the remote enable signal. The machine is also adapted to disable the same action of the drilling machine upon detecting an absence of the remote enable signal for a predetermined number of intervals, each interval being of a preselected duration.

Abstract: Apparatus and methods for drilling with casing. In an embodiment, methods and apparatus for deflecting casing using a diverter apparatus are disclosed. In another embodiment, the apparatus comprises a motor operating system disposed in a motor system housing, a shaft operatively connected to the motor operating system, the shaft having a passageway, and a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft. In another aspect, methods and apparatus for directionally drilling a casing into the formation are disclosed. Methods and apparatus for measuring the trajectory of a wellbore while directionally drilling a casing into the formation are also described.

Abstract: The present invention provides a drilling assembly for drilling deviated wellbores. The drilling assembly includes a drill bit at the lower end of the drilling assembly. A drilling motor provides the rotary power to the drill bit. A bearing assembly of the drilling motor provides lateral and axial support to the drill shaft connected to the drill bit. A steering device is integrated into drilling motor assembly. The steering device contains a plurality of force application members disposed at an outer surface of the drilling motor assembly. Each force application member is adapted to move between a normal position and a radially extended position to exert force on the wellbore interior when in extended position. A power unit in the housing provides pressurized fluid to the force application members. A control device for independently operating each of the force application members is disposed in the drilling motor assembly.

Abstract: A boring tool moves having a pitch orientation, a yaw orientation and a roll orientation and is steerable underground using the roll orientation. A maximum drill string curvature is established for steering. The boring tool is advanced over a path segment. An averaged roll characteristic is determined for movement of the boring tool along the path segment. A path segment pitch orientation is established based on at least one measured pitch orientation along the path segment. Using the maximum drill string curvature in combination with the averaged roll characteristic and the path segment pitch orientation, the yaw orientation is determined. The averaged roll characteristic is determined based on a series of incremental roll measurements that are spaced across the path segment. A set of coupled ordinary differential equations is used to characterize movement of the boring tool.

Abstract: An apparatus for steerable rotary drilling of a borehole having a wall in the earth comprising a mandrel having a central opening there through for the passage of drilling fluids. The mandrel having a lower connection for operatively connecting to a drill bit structure and an upper connection for operatively connecting to a drill string above said apparatus. The mandrel further having an intermediate portion, an outer housing surrounding longitudinal extent of the mandrel intermediate portion, a differential displacement drive within the outer housing, one or more pairs of radially-extensible, opposed side-force exerting elements controlled by the differential displacement drive to provide for side force exertion against the borehole wall.

Abstract: A method of automatic drilling of a well with coil tubing or drill pipe tubing utilizes AC motors coupled to variable frequency drives controlled by a programmable logic controller. For example, a coil tube injector is supported in a mast for injecting coil tube from a reel and into a wellbore for drilling the wellbore. The AC motors for the injector are driven for controlling a rate of injection of coil tube by the injector for maintaining at least one drilling parameter such as weight-on-bit, differential mud pressure or rate of penetration. The AC motor for the reel is also controlled for driving the reel and maintaining a relative rate of coil tube supplied from the reel to the injector. Drawworks and a top drive supported by the draworks can also be equipped with AC motors and variable frequency drives for controlling a drilling rate for maintaining at least one of the drilling parameters.

Abstract: A rotary steerable apparatus is provided having an actuator for pushing the bit or pointing the bit that includes a shape memory alloy. An elongated form of the alloy, such as a wire or rod, is employed in a mechanism that applies force in a direction transverse to the wellbore in response to a change in length of the alloy. Temperature of the alloy is controlled to change shape and produce the desired force on pads for operating the apparatus. The apparatus may be used with downhole power generation and control electronics to steer a bit, either in response to signals from the surface or from downhole instruments.

Abstract: The disclosed orienter for use in drilling a subterranean borehole enables use of the torque provided by the drilling motor to both orient the rotating drill bit for drilling an arcuate section of the borehole and rotating the orienter housing, including a fixed bend for drilling a straight section of the borehole.

Abstract: A control system for controlling at least one function of an item of construction equipment. The control system includes a pump, a proportional control valve, a directional control valve, a signal source, a switch, and a processor. The proportional control valve is in fluid communication with the pump and the directional control valve is in fluid communication with the proportional control valve. The switch is adapted to be in an open position and in a closed position. The processor is adapted to receive a processor input, receive the signal from the signal source, and transmit a processor output to the proportional control valve. The switch transmits a false signal to the processor when it is in the open position and a true signal when it is in the closed position. The control system is adapted to control the at least one function of the item of construction equipment.

Abstract: A method for determining a rate of change of longitudinal direction of a subterranean borehole is provided. The method includes positioning a downhole tool in a borehole, the tool including first and second surveying devices disposed thereon. The method further includes causing the surveying devices to measure a longitudinal direction of the borehole at first and second longitudinal positions and processing the longitudinal directions of the borehole at the first and second positions to determine the rate of change of longitudinal direction of the borehole between the first and second positions. The method may further include processing the measured rate of change of longitudinal direction of the borehole and a predetermined rate of change of longitudinal direction to control the direction of drilling of the subterranean borehole.

Abstract: Systems and methods for directionally drilling a borehole are provided. One system includes a biasing subsystem that is configured to control a tendency of a bottom hole assembly during drilling of the borehole. The system also includes a continuously variable transmission. An output shaft of the continuously variable transmission is coupled to the biasing subsystem such that the continuously variable transmission is configured to control relative rotation of one or more components of the biasing subsystem during the drilling. One method includes controlling a tendency of a bottom hole assembly during drilling of the borehole using a biasing subsystem. The method also includes controlling relative rotation of one or more components of the biasing subsystem using a continuously variable transmission during the drilling. The one or more components are coupled to an output shaft of the continuously variable transmission.

Abstract: A system for controlling sensor motion during a time-dependent measurement, comprising a drilling assembly having a drill bit at one end and engaged with a drill string extending to a surface location at an opposite end thereof. A sensor is disposed in the drilling assembly for making a measurement of a formation parameter of interest. A non-rotating stabilizer is disposed in the drilling assembly proximate the sensor. The non-rotating stabilizer is adapted to reduce motion of the sensor below a predetermined level during the measurement. In one embodiment the rotational axis of the stabilizer is eccentric with respect to the borehole. In another embodiment, the non-rotating stabilizer has an extendable rib for changing the effective diameter of the stabilizer.

Abstract: A directional borehole drilling system employs a controllable drill bit, which includes one or more conical drilling surfaces. Instrumentation located near the bit measures present position when the bit is static, and dynamic toolface when the bit is rotating. This data is processed to determine the error between the present position and a desired trajectory, and the position of one or more of the bit's leg assemblies is automatically changed as needed to make the bit bore in the direction necessary to reduce the error. The controllable drill bit preferably comprises three leg assemblies mounted about the bit's central axis, each leg having a “toed-out” axle. In response to a command signal, a lower leg translates along the bit axis to cause it to bear more of the bit weight, thus excavating more deeply over the commanded toolface sector and causing the bit to bore in a preferred direction.

Abstract: A boring tool moves having a pitch orientation, a yaw orientation and a roll orientation and is steerable underground using the roll orientation. A maximum drill string curvature is established for steering. The boring tool is advanced over a path segment. An averaged roll characteristic is determined for movement of the boring tool along the path segment. A path segment pitch orientation is established based on at least one measured pitch orientation along the path segment. Using the maximum drill string curvature in combination with the averaged roll characteristic and the path segment pitch orientation, the yaw orientation is determined. The averaged roll characteristic is determined based on a series of incremental roll measurements that are spaced across the path segment. A set of coupled ordinary differential equations is used to characterize movement of the boring tool.

Abstract: A portable mapping tool for use in a horizontal drilling system and associated methods use a boring tool configured for transmitting a locating signal. The mapping tool also includes at least one electromagnetic field detector which is configured for measuring the locating signal from a fixed position proximate to the surface of the ground in a drilling area. The mapping tool includes a housing and a transmitter arrangement supported by the housing for transmitting a setup locating signal for reception by the detector in the region for use in determining certain initial conditions at least prior to drilling. The associated methods include the step of configuring the mapping tool for transmitting a setup locating signal for reception by the detector in the region and using the received setup locating signal in determining certain initial conditions at least prior to drilling.

Abstract: A system for determining the location of and communicating with a downhole tool assembly. A tracker assembly comprises a vertical transmitting antenna, a plurality of receiving antennas, and a processor. The downhole tool assembly has a beacon assembly comprising a plurality of receiving antennas, a transmitting antenna, an orientation sensor, and a processor. The transmitter in the tracker transmits a substantially vertical dipole field. The beacon assembly detects the vertical field and processes the signals to determine the location of the beacon relative to the tracker. The beacon assembly transmits the beacon location and operational information to the tracker assembly. The tracker assembly displays the beacon location and operational information on a visual display. The tracker assembly may also transmit operational commands or requests for information to the beacon assembly.

Abstract: A downhole drilling apparatus suspended by tubing includes a drill bit driven by an electric motor powered by a cable means. The motor is mounted upon a hollow shaft which allows fluid to pass through, so that a fluid circuit along the tube and back along the annulus between the borehole and the tubing via the drill bit is established. The state of the motor, particularly its speed and torque, can be monitored, and the motor may then be regulated as a result of the this data. Various sensors may be included in the drilling apparatus, and the data gathered similarly used to regulate the motor. Thrust means are included to urge the drill along the borehole. Supplementary pumps may be provided to assist the fluid flow. Both the thrust means and the pumps may be controlled by the control means.

Abstract: A method of and system for directional drilling alternate between rotary drilling and sliding drilling with the bit remaining in continuous contact with the bottom of the bore hole.

Abstract: A telemetry system and method for communicating information axially along a drill string comprised of a drive train supported within a housing. The system includes an axial conducting loop formed by the drill string for conducting an axial electrical signal embodying the information between a first axial position and a second axial position in the drill string, which axial conducting loop extends between the first and second axial positions. A transmitter transmits information to the axial conducting loop. The drive train includes a downhole end which extends from and is located below the housing. At least one of the first and second axial positions is located in the downhole end. The method includes the step of conducting the axial electrical signal between the first and second axial positions through the axial conducting loop which extends between the first and second axial positions.

Abstract: A portable mapping tool for use in a horizontal drilling system and associated methods use a boring tool configured for transmitting a locating signal. The mapping tool also includes at least one electromagnetic field detector which is configured for measuring the locating signal from a fixed position proximate to the surface of the ground in a drilling area. The mapping tool includes a housing and a transmitter arrangement supported by the housing for transmitting a setup locating signal for reception by the detector in the region for use in determining certain initial conditions at least prior to drilling. The associated methods include the step of configuring the mapping tool for transmitting a setup locating signal for reception by the detector in the region and using the received setup locating signal in determining certain initial conditions at least prior to drilling.

Abstract: An autonomous subsurface drilling device has spaced-apart forward and rearward “feet” sections coupled to an axial thruster mechanism between them to operate using an inchworm method of mobility. In one embodiment, forward and rearward drill sections are carried on forward and rearward “feet” sections for drilling into material in the borehole in both forward and rearward directions, to allow the device to maneuver in any direction underground. In another embodiment, a front drill section has a drill head for cutting into the borehole and conveying cuttings through a center spine tube to an on-board depository for the cuttings. The feet sections of the device employ a foot scroll drive unit to provide radial thrust and synchronous motion to the feet for gripping the borehole wall. The axial thrust mechanism has a tandem set of thrusters in which the second thruster is used to provide the thrust needed for drilling, but not walking.

Abstract: The present invention provides a drilling assembly for drilling deviated wellbores. The drilling assembly includes a drill bit at the lower end of the drilling assembly. A drilling motor provides the rotary power to the drill bit. A bearing assembly of the drilling motor provides lateral and axial support to the drill shaft connected to the drill bit. A steering device is integrated into drilling motor assembly. The steering device contains a plurality of force application members disposed at an outer surface of the drilling motor assembly Each force application member is adapted to move between a normal position and a radially extended position to exert force on the wellbore interior when in extended position. A power unit in the housing provides pressurized fluid to the force application members. A control device for independently operating each of the force application members is disposed in the drilling motor assembly.

Abstract: A system is for controlling borehole operations using a computational drilling process model representing the combined effect of downhole conditions and the operation of a drillstring. The drilling process model is continually updated with downhole measurements made during a drilling operation. From the updated drilling process model, a set of optimum drilling parameters is determined and communicated to a surface equipment control system. Further, the system allows the surface equipment control system to automatically adjust current surface equipment control settings based on the updated optimum drilling parameters. Various control scripts are generated and executed to inform the surface equipment control system based on a present drilling mode.

Abstract: A steering tool for extended-reach directional drilling in three dimensions comprises a mud pulse telemetry section, a rotary section, and a flex section assembled as an integrated system in series along the length of the tool. The flex section comprises a flexible drive shaft and a deflection actuator for applying hydraulic pressure along the length of the shaft for bending the shaft when making inclination angle adjustments during steering. The rotary section comprises a rotator housing coupled to the deflection housing for rotating the deflection housing for making azimuth angle adjustments during steering. The onboard mud pulse telemetry section receives inclination and azimuth angle steering commands together with actual inclination and azimuth angle feedback signals during steering for use in controlling operation of the flex section and rotary section for steering the tool along a desired course.

Abstract: A portable mapping tool for use in a horizontal drilling system and associated methods use a boring tool configured for transmitting a locating signal. The mapping tool also includes at least one electromagnetic field detector which is configured for measuring the locating signal from a fixed position proximate to the surface of the ground in a drilling area. The mapping tool includes a housing and a transmitter arrangement supported by the housing for transmitting a setup locating signal for reception by the detector in the region for use in determining certain initial conditions at least prior to drilling. The associated methods include the step of configuring the mapping tool for transmitting a setup locating signal for reception by the detector in the region and using the received setup locating signal in determining certain initial conditions at least prior to drilling.

Abstract: A method of and system for directional drilling reduces the friction between the drill string and the well bore. A downhole drilling motor is connected to a drilling rig at the surface by a drill string. The drilling motor is oriented at a selected tool face angle. The drill string is rotated at the surface in a first direction until a first torque magnitude is reached without changing the tool face angle. The drill string is then rotated in the opposite direction until a second torque magnitude is reached, again without changing the tool face angle. The drill string is rotated back and forth between the first and second torque magnitudes. Pressure inside the drill string is measured, and the first and second torque magnitudes are adjusted in response to changes in the pressure.