Abstract: Disclosed is an automatic force adjustment control system for mobile drilling machines and methods for automatically adjusting a force on a down-the-hole drill bit of a drill string of a mobile drilling machine. A method may include: monitoring bit air pressure of the down-the-hole drill bit during an automatic down-the-hole drilling operation; and automatically adjusting a force provided to the drill string based on the monitored bit air pressure so that the bit air pressure approaches a target air pressure value.

Abstract: A system for tracking a below-ground transmitter from an aerial receiver. The receiver has an antenna assembly, a processor, and a propulsion system. The antenna assembly detects the magnetic field from an underground transmitter and generates an antenna signal. The processor is programmed to receive the antenna signal and generate a command signal, which moves the receiver to a position above the transmitter. Once in the desired position, which may be a reference plane at a fixed elevation, the antenna assembly measures the magnetic field to determine the location of the drill bit along borepath.

Abstract: Methods, systems, and techniques for controlling the rate of penetration of a drill bit use drilling parameter measurements read from drilling parameter sensors to evaluate control loops, with the output of one of the control loops at any given time being used by an automatic driller to control the rate of penetration. For each of the drilling parameters, the automatic driller reads a drilling parameter measurement, determines an error measurement that represents a difference between a drilling parameter setpoint and the drilling parameter measurement, and from the error measurement determines an output signal proportional to the rate of penetration of the drill bit. The output signal of one of the control loops is subsequently selected and used to control the rate of penetration.

Abstract: Techniques for optimizing automated drilling processes are disclosed. Such techniques include modeling a formation and selecting a drilling trajectory in the formation. Measurements of rate of penetration (ROP), revolutions per minute (RPM), weight-on-bit (WOB) and torque-on-bit (TOB) of a drilling string at a position on the drilling trajectory in the formation are received. A functional relationship between depth of cut (DOC), WOB, and TOB for the modeled formation is determined. Operating constraints defining a safe operating envelope as a function of RPM and WOB along the selected drilling trajectory are determined, and an optimal RPM and WOB is determined based on operating constraints. A cost function of RPM and WOB is determined, and a path from current RPM and WOB to optimal RPM and WOB is determined based on the cost function.

Abstract: Methods of identifying rock properties in real-time during drilling, are provided. An example of such a method includes connecting a downhole sensor subassembly between a drill bit and a drill string, operably coupling acoustic sensors to a downhole data interface, and operably coupling a surface computer to the downhole data interface. The method can also include receiving raw acoustic sensor data generated real-time as a result of rotational contact of the drill bit with rock during drilling, transforming the raw data into the frequency domain, filtering the transformed data, and deriving a plurality of acoustic characteristics from the filtered data. This can be performed by a petrophysical properties analyzing program stored in memory of the computer. The method can also include deriving petrophysical properties from the filtered data utilizing a petrophysical properties evaluation algorithm employable to predict one or more petrophysical properties of rock undergoing drilling.

Abstract: The invention provides a control system and method for limiting vibrations in a tool string system. The system comprises a pump connected to a rotatable tool string driven by a drive system. The control system comprises feedback of both torque and rotational speed signals into a controller. An objective of said controller is to maintain the drive speed over torque ratio equal to the connected tool string impedance (Z). A secondary objective, for lower frequencies, is to approach and maintain a setpoint speed as drive rotation speed. The system includes a rotational speed sensor and a torque sensor, with the latter optionally replaced by a motor torque signal already available from a variable frequency drive (VFD) for an AC motor and the current safeguarding signal for a DC motor.

Abstract: The invention provides a control system and method for limiting vibrations in a tool string system, comprising a relatively heavy rotatable device, such as a pump system or a bottom hole assembly, connected to a long rotatable tool string driven by a drive system. The control system comprises feedback of both torque and rotational speed signals to correct the set rotational speed. An objective is to maintain the drive speed over torque ratio equal to the connected tool string impedance. A secondary objective, for lower frequencies, is to approach and maintain a setpoint speed as drive rotation speed. The system may include a rotational speed sensor and a torque sensor, with the latter optionally replaced by a motor torque signal already available from a variable frequency drive (VFD) for an AC motor and the current safeguarding signal for a DC motor.

Abstract: A method and device for monitoring down-the-hole percussion drilling. A down-the-hole hammer is supplied with percussion and flushing fluid flow. The down-the-hole hammer is subjected to rotational force and to feed force. Percussion frequency or a related frequency of the down-the-hole hammer is sensed. A representation of a spread thereof is created so as to produce a response to an adjustment of at least one drilling parameter as a change of width of the spread.

Abstract: A downhole signal transmission system provides electric radiofrequency signals that are coupled to electrically conductive or non-conductive fluids through electrical insulators. A plurality of signal repeaters are tuned to the frequencies of the radiofrequency signals, and a plurality of transmission lines terminated by resonance circuits are also provided such that the terminating resonance circuits resonate on the frequencies of the electric radiofrequency signals. The plurality of signal repeaters and plurality of transmission elements are arranged to be redundant such that a failure of one or more of the signal repeaters or a failure of one or more of the transmission elements does not substantially affect the operation of the data transmission system. The signal repeaters and transmission elements also are arranged such that a failure of any of the signal repeaters or a failure of any of the transmission elements is communicated to the surface.

Abstract: Apparatus for identifying rock properties in real-time during drilling, are provided. An example of an embodiment of such an apparatus includes one or more acoustic sensors positioned to detect drill sounds emanating from the drill bit and the rock encountered during drilling operations, connected to select components of a drilling rig to maximally pick up the drill sounds of the drill bit engaging rock during drilling operations. The apparatus also includes an inductive telemetry, wireless telemetry, or wired transmitting system. The apparatus also includes a computer to analyze the acoustic signals received from the acoustic sensors through the respective transmitting system for lithology type and petrophysical properties.

Abstract: Methods for identifying rock properties in real-time during drilling, are provided. An example of an embodiment of such a method includes positioning one or more acoustic sensors to detect drill sounds emanating from the drill bit and the rock encountered during drilling operations, connecting the sensors to select components of a drilling rig to maximally pick up the drill sounds of the drill bit engaging rock during drilling operations. The method also includes providing and deploying an inductive telemetry, wireless telemetry, or wired transmitting system. The method also includes providing and configuring a computer to analyze the “raw” acoustic signals received from the acoustic sensors through the respective transmitting system.

Abstract: A method of processing downhole measurement data includes: receiving formation measurement data generated by a downhole tool during a logging-while drilling operation over a selected time period; receiving a measured depth corresponding to the selected time period based on data taken at a surface location; receiving tool rotation data generated by measurements of a rotational rate of the downhole tool taken by a downhole sensor during the selected time period; calculating a new depth of the tool as a function of time over the selected time period based on a relationship between the tool rotation data and the measured depth; and correcting an original depth of the measurement data with the new depth.

Abstract: A drilling system performs underground boring using a drill rig and a boring tool which is configured for moving through the ground under control of the drill rig to form an underground bore. A monitoring arrangement, forming part of the system, includes a detection arrangement at the drill rig for monitoring at least one operational parameter to produce a data signal relating to at least one of a utility to be installed in the underground bore, the drill rig and the boring tool. A portable device forms another part of the system for receiving the data signal relating to the operational parameter for use by the portable device. A communication arrangement, for example using telemetry, transfers the data signal from the drill rig to the portable device. The operational parameter may be monitored for the purpose of preventing equipment failure.

Abstract: An apparatus and method of performing a wellbore operation. The apparatus includes a drill bit that has a cavity at an end thereof and a communication device placed in the cavity. The communication device includes a first section and a second section. An outer dimension of the second section is greater than an outer dimension of the first section. The second section includes a conduit configured to allow passage of a conductor from the drill bit to a location outside the drill bit so as to provide a direct connection of the conductor from the drill bit to an element outside the drill bit.

Abstract: A downlinking signal is transmitted downhole from the surface using drilling fluid as the communications medium. The downlinking signal includes at least a synchronization phase and a command phase. The downlinking signal is differentiated upon reception such that attributes of the synchronization phase may be used to determine corresponding attributes of the command phase. Commands may be transmitted downhole while drilling and simultaneously while using mud-pulse telemetry uplinking techniques.

Abstract: A method for drilling a well along a planned trajectory includes: receiving downhole data from a steerable drilling tool; processing the downhole data and creating a downlink path, the downlink path being recognizable by the steerable drilling tool; and controlling the trajectory of the steerable drilling tool based on the downlink path.

Abstract: A method for removing cyclic noise from a borehole image includes transforming the image into the frequency domain using a two-dimensional (2-D) Fourier Transform, removing cyclic noise components from the transformed image, and inverse transforming the image back into the spatial domain using an inverse 2-D Fourier Transform. The cyclic noise component may also be isolated by subtracting the corrected image from the original image or by removing all non-cyclic noise components from the transformed image prior to inverse transforming. Removal of the cyclic noise from a borehole image tends to enable the identification of borehole features and provide for improved accuracy in formation parameter evaluation. Evaluation of the cyclic noise component may also enable the source of the noise to be identified and mitigated.

Abstract: A downlinking signal is transmitted downhole from the surface using drilling fluid as the communications medium. The downlinking signal includes at least a synchronization phase and a command phase. Attributes of the synchronization phase are used upon reception of the signal to determine corresponding attributes of the command phase. Commands may be transmitted downhole while drilling and simultaneously while using mud-pulse telemetry uplinking techniques.

Abstract: The present invention relates to a downhole system (200) comprising a casing (3) having an inner wall. Furthermore, the downhole system comprises a wireless unit (1) which is movable within the casing, comprising driving means (7) in the form of wheels and at least one battery pack (8) comprising at least one battery for powering an electrical motor (5) driving a pump (6) driving the wheels to rotate along the inner wall of the casing, wherein the downhole system further comprises a well head (110) having a sound detection device (16) for detecting vibrations in the casing, e.g. caused by the driving means or an operation performed by the wireless unit.

Abstract: A drilling system performs underground boring using a drill rig and a boring tool which is configured for moving through the ground under control of the drill rig to form an underground bore. A monitoring arrangement, forming part of the system, includes a detection arrangement at the drill rig for monitoring at least one operational parameter to produce a data signal relating to at least one of a utility to be installed in the underground bore, the drill rig and the boring tool. A portable device forms another part of the system for receiving the data signal relating to the operational parameter for use by the portable device. A communication arrangement, for example using telemetry, transfers the data signal from the drill rig to the portable device. The operational parameter may be monitored for the purpose of preventing equipment failure.

Abstract: A logging system and method for measuring propped fractures and down-hole subterranean formation conditions including: a radar source; an optical source; an optical modulator for modulating an optical signal from the optical source according to a signal from the radar source; a photodiode for converting the modulated optical signal output from the optical modulator to the source radar signal. A transmitter and receiver unit receives the source radar signal from the photodiode and transmits the source radar signal via at least one antenna attached to the casing and in communication with at least one photodiode into the formation and receives a reflected radar signal. A mixer mixes the reflected radar signal with the source radar signal to provide an output. This can describe fractures connected to the wellbore and differentiate between the dimensions of the two vertical wings of a propped fracture.

Abstract: A drilling system has multiple cutting structures, including a bit and one or more secondary cutting structures. A method balances the rate of penetration of the drilling system and the wear on the cutting structures by controlling weight on bit and RPM. The method includes calculating a predicted rate of penetration for the bit, using in the calculation the current predicted wear on the bit and the properties of the rock to be penetrated by the bit. The method includes calculating a predicted rate of penetration for at least one of the one or more secondary cutting structures, using in the calculation the current predicted wear on the secondary cutting structure and the properties of the rock to be penetrated by the secondary cutting structure. The method includes determining the slowest rate of penetration among those calculated for the bit and at least one the one or more secondary cutting structures.

Abstract: A system for communicating with downhole tools and devices is disclosed. The system includes multiple communication devices which, in combination, permit operators at the surface to operate downhole tools and to receive feedback regarding the state of the tools.

Abstract: A system for measuring an acoustic property of material penetrated by a well borehole. The system uses a borehole logging tool comprising preferably one acoustic transmitter and preferably a plurality of acoustic receivers. An independent measurement is used to determine azimuthal orientation of the tool within the borehole. Firings of the transmitter are based upon azimuthal orientation of the tool. Receiver responses resulting from preferably a plurality of transmitter firings per tool revolution are combined to form at least one composite transmitter response. The composite receiver response is compensated for adverse effects of the tool operating eccentered within the borehole.

Abstract: A method to detect the relative position of a drill bit with respect to a coal seam boundary using an electric-field borehole telemetry apparatus, that includes the steps: providing a measure-while-drilling apparatus that includes inclination sensors, directional sensors, logging sensors of choice and an electric-field borehole telemetry apparatus, within the electric-field borehole telemetry apparatus, in addition to monitoring the inclination, direction and logging parameters, monitoring one or more parameters of the electrical output of the telemetry apparatus, transmitting to the surface the inclination, direction and logging parameters as well as the one or more parameters of the electrical output by means of the telemetry apparatus, computing the usual drilling parameters needed to guide the drill string along the intended path, determining from the one or more transmitted parameters of the electrical output from the downhole apparatus parameters indicative of approaching or penetrating the coal boundar

Abstract: An embodiment of a wireless telemetry system for providing signal communication across a wired-communication gap in a bottom-hole assembly (“BHA”), the BHA having an upper portion and a lower portion separated by the wired-communication gap, includes an upper transceiver positioned in the upper portion and in signal communication with a surface telemetry system and a lower transceiver positioned in the lower portion and in signal communication with a drilling tool, the upper and the lower transceivers in signal communication with one another via wireless induction telemetry. Each transceiver may include an antenna that is positioned within the bore of a drill collar adjacent to a thinned wall section in the drill collar. The thinned wall section may include one or more of increasing an inside diameter relative to a base inside diameter of the bore and decreasing an outside diameter relative to a base outside diameter of the drill collar.

Abstract: A method for a pressure release encoding system for communicating downhole information through a wellbore to a surface location includes positioning a valve and a brake in a drilling mud circulation system, initiating flow of drilling mud through the system, sensing flow through the valve and setting the brake at predefined pressure levels, sensing downhole conditions and releasing corresponding percentages of pressure across the valve at time intervals, and determining the downhole conditions at the surface by analyzing those associated time intervals. The method includes activation of the encoding system using drilling mud flow and setting predefined pressure levels, so that the pressure drops in the encoding process are from predefined levels at equilibrium and independent of fluid flow.

Abstract: A drilling system performs underground boring using a drill rig and a boring tool which is configured for moving through the ground under control of the drill rig to form an underground bore. A monitoring arrangement, forming part of the system, includes a detection arrangement at the drill rig for monitoring at least one operational parameter to produce a data signal relating to at least one of a utility to be installed in the underground bore, the drill rig and the boring tool. A portable device forms another part of the system for receiving the data signal relating to the operational parameter for use by the portable device. A communication arrangement, for example using telemetry, transfers the data signal from the drill rig to the portable device. The operational parameter may be monitored for the purpose of preventing equipment failure.

Abstract: A system and method of interfacing a drilling machine with one of a number of different walk-over guidance systems involves receiving an ID signal from a particular walk-over guidance system selected for use with the drilling machine. A protocol library associated with the particular walk-over guidance system is accessed in response to the ID signal. The protocol library is used to effect communication between the particular walk-over guidance system and a control system of the drilling machine during cooperative use of the particular walk-over guidance system and drilling machine. Using the protocol library involves converting, as prescribed by the protocol library, locator signals received from the particular walk-over guidance system from a locator protocol to a common protocol used by the control system of the drilling machine. Locator and drilling machine data of various types can be presented to a drilling machine operator via an on-board display.

Abstract: A drilling system has multiple cutting structures, including a bit and one or more secondary cutting structures. A method balances the rate of penetration of the drilling system and the wear on the cutting structures by controlling weight on bit and RPM. The method includes calculating a predicted rate of penetration for the bit, using in the calculation the current predicted wear on the bit and the properties of the rock to be penetrated by the bit. The method includes calculating a predicted rate of penetration for at least one of the one or more secondary cutting structures, using in the calculation the current predicted wear on the secondary cutting structure and the properties of the rock to be penetrated by the secondary cutting structure. The method includes determining the slowest rate of penetration among those calculated for the bit and at least one the one or more secondary cutting structures.

Abstract: A system and method of interfacing a drilling machine with one of a number of different walk-over guidance systems involves receiving an ID signal from a particular walk-over guidance system selected for use with the drilling machine. A protocol library associated with the particular walk-over guidance system is accessed in response to the ID signal. The protocol library is used to effect communication between the particular walk-over guidance system and a control system of the drilling machine during cooperative use of the particular walk-over guidance system and drilling machine. Using the protocol library involves converting, as prescribed by the protocol library, locator signals received from the particular walk-over guidance system from a locator protocol to a common protocol used by the control system of the drilling machine. Locator and drilling machine data of various types can be presented to a drilling machine operator via an on-board display.

Abstract: A system and method for communicating with a downhole tool is disclosed. In one embodiment, a telemetry system for communicating with a downhole tool in a wellbore includes a first electrode. A modulated electric current flows from the first electrode through a formation to the downhole tool. The telemetry system also includes a downlink box, which provides the modulated electric current to the first electrode. The downhole tool comprises a sensor unit, which detects the modulated electric current. The telemetry system includes a second electrode that allows the modulated electric current to return to the downlink box. The telemetry system also includes an uplink telemetry, wherein the uplink telemetry does not comprise electromagnetic telemetry. In some embodiments, the downlink may be operated while mud pumps are turned off. The downlink may also be operated while the downhole tool is sending uplink telemetry by a method other than electromagnetic current.

Abstract: A method of drilling a well. The method includes calculating an estimated formation dip angle, wherein said estimated formation dip angle being based on offset well data, seismic data, core data, pressure data. Next, the method includes drilling a well with a logging while drilling means so that real time logging data is generated along with drilling data and calculating an instantaneous formation dip angle. Next, real time logging data is obtained and a target formation window is projected ahead of the well path that includes a top of formation and a bottom formation. The method includes monitoring the real time logging and drilling data and drilling the well through the target formation window. The method further includes changing the estimated instantaneous formation dip based on the obtained data and adjusting the target formation top and bottom window.

Abstract: A system for communicating with downhole tools and devices is disclosed. The system includes multiple communication devices which, in combination, permit operators at the surface to operate downhole tools and to receive feedback regarding the state of the tools.

Abstract: A drilling system performs underground boring using a drill rig and a boring tool which is configured for moving through the ground under control of the drill rig to form an underground bore. A monitoring arrangement, forming part of the system, includes a detection arrangement at the drill rig for monitoring at least one operational parameter to produce a data signal relating to at least one of a utility to be installed in the underground bore, the drill rig and the boring tool. A portable device forms another part of the system for receiving the data signal relating to the operational parameter for use by the portable device. A communication arrangement, for example using telemetry, transfers the data signal from the drill rig to the portable device. The operational parameter may be monitored for the purpose of preventing equipment failure.

Abstract: A system and method of interfacing a drilling machine with one of a number of different walk-over guidance systems involves receiving an ID signal from a particular walk-over guidance system selected for use with the drilling machine. A protocol library associated with the particular walk-over guidance system is accessed in response to the ID signal. The protocol library is used to effect communication between the particular walk-over guidance system and a control system of the drilling machine during cooperative use of the particular walk-over guidance system and drilling machine. Using the protocol library involves converting, as prescribed by the protocol library, locator signals received from the particular walk-over guidance system from a locator protocol to a common protocol used by the control system of the drilling machine. Locator and drilling machine data of various types can be presented to a drilling machine operator via an on-board display.

Abstract: An acoustic position measurement system and method includes an acoustic transmitter operable to transmit a sound wave into an underground well bore in a target formation. The sound wave is configured to reflect from a boundary formation proximate the target formation. The system includes an acoustic receiver operable to receive a reflected sound wave. The reflected sound wave comprises a reflection of the sound wave from the boundary formation. The system also includes an electronics portion electrically coupled to the acoustic receiver. The electronics portion is operable to process the reflected sound wave and produce, based upon a characteristic of the reflected sound wave, data output indicative of a position of the acoustic position measurement system in the target formation.

Abstract: A drilling system performs underground boring using a drill rig and a boring tool which is configured for moving through the ground under control of the drill rig to form an underground bore. A monitoring arrangement, forming part of the system, includes a detection arrangement at the drill rig for monitoring at least one operational parameter to produce a data signal relating to at least one of a utility to be installed in the underground bore, the drill rig and the boring tool. A portable device forms another of the system for receiving the data signal relating to the operational parameter for use by the portable device. A communication arrangement, for example using telemetry, transfers the data signal from the drill rig to the portable device. The operational parameter may be monitored for the purpose of preventing equipment failure.

Abstract: An apparatus and method for horizontally drilling provides for detecting subsurface features and avoiding such features during closed-loop control of an underground drilling machine. A horizontal drilling system includes a base machine capable of propelling a drill pipe rotationally and longitudinally underground. A cutting tool system is coupled to the drill pipe, and a control system controls the base machine. A detector is employed to detect a subsurface feature. A communication link is utilized for transferring data between the detector and the control system. The control system uses the data generated by the detector to modify control of the base machine in response to detection of the subsurface feature.

Abstract: A method for simulating the drilling performance of a roller cone bit drilling an earth formation may be used to generate a visual representation of drilling, to design roller cone drill bits, and to optimize the drilling performance of a roller cone bit. The method for generating a visual representation of a roller cone bit drilling earth formations includes selecting bit design parameters, selecting drilling parameters, and selecting an earth formation to be drilled. The method further includes calculating, from the bit design parameters, drilling parameters and earth formation, parameters of a crater formed when one of a plurality of cutting elements contacts the earth formation. The method further includes calculating a bottomhole geometry, wherein the crater is removed from a bottomhole surface.

Abstract: A method for calibrating a pitch measurement of a horizontal underground bore location system includes providing a probe having a pitch sensor that measures deviation between a predetermined orientation and a measurement axis. A receiver has an antenna that detects a signal radiated by the probe and has receiver circuitry that detects the deviation from the received signal. A bore head is aligned with the predetermined orientation. The probe is placed in the bore head. The receiver detects the deviation when the bore head is aligned with the predetermined orientation. The receiver offsets deviation measurements thereafter detected from the probe by the measured deviation.

Abstract: An apparatus and method are employed to detect underground objects for use with a horizontal directional drilling (HDD) machine. A drill pipe is configured to cooperate with the HDD machine to produce a horizontal bore. A transmit apparatus is provided with the drill pipe and transmits electromagnetic probe signals ahead and/or to the side of the drill pipe. A receive apparatus is provided with the drill pipe and receives electromagnetic return signals resulting from the probe signals. A processor, coupled to the transmit and receive apparatuses, compares at least some of the return signals, and generates an alert signal indicative of a detected object in proximity with the drill pipe. HDD machine activity is modified, such as by reducing or halting drill pipe advancement, in response to the alert signal.

Abstract: A method for improving ROP and reducing hazards in drilling subterranean wells by using an acoustical system 15 to look ahead of the drill bit 14, detects and analyzes geologic features ahead of the bit 14 which may be qualified as drilling hazards 17. Detection of such hazards 17 may facilitate use of more aggressively penetrating bits 14 such as PDC bits as opposed to roller cone bits. In addition, other drilling parameters may be adjusted to improve ROP due to the ability to timely respond to identified hazards 17 before they may be detrimentally encountered by the bit 14. The acoustic system 15 may look ahead of the bit 14 by at least 100 meters, using propagated acoustic waves 19 to locate changes in acoustic impedance which may represent drilling hazards 17. In addition, bulk resistivity ahead of the bit 14 may also be measured and used to locate drilling hazards 17.

Abstract: A remote lock-out system and method are employed with a drilling machine. The remote lock-out system includes a remote lock-out override controller capable of interrupting a drilling operation of the drilling machine. The remote lock-out override controller includes a transmitter and a receiver. A remote lock-out controller is capable of issuing a lock-out signal and a run signal, wherein the lock-out signal, when received by the HDD machine, initiates suspension of the HDD machine drilling operation, and the run signal initiates enablement of the HDD machine drilling operation. The remote lock-out controller includes a transmitter and a receiver. The HDD machine drilling operation generally includes displacing and rotating the drill string, and can further include supplying a drilling fluid through the drill string.

Abstract: An auger drill directional control system includes a positional transmitter mounted on a drillhead at the front of a pipe, the positional transmitter transmitting directional and pitch signals to a positional receiver disposed above the grade at the desired terminal location of the drillhead; the positional receiver transfers the signal information to the positional processor that detects deviations by the drillhead from the desired course of travel and produces a correction signal to compensate for the deviation; the correction signal is transmitted by a control transmitter and is received by a control receiver disposed on the underground boring machine; the control receiver passes the correction signal to the control processor which converts the correction signal into a correction command that is delivered to an adjustment apparatus operatively connected with the drillhead.

Abstract: A method for simulating the drilling performance of a roller cone bit drilling an earth formation may be used to generate a visual representation of drilling, to design roller cone drill bits, and to optimize the drilling performance of a roller cone bit. The method for generating a visual representation of a roller cone bit drilling earth formations includes selecting bit design parameters, selecting drilling parameters, and selecting an earth formation to be drilled. The method further includes calculating, from the bit design parameters, drilling parameters and earth formation, parameters of a crater formed when one of a plurality of cutting elements contacts the earth formation. The method further includes calculating a bottomhole geometry, wherein the crater is removed from a bottomhole surface.

Abstract: A method for improving ROP and reducing hazards in drilling subterranean wells by using an acoustical system 15 to look ahead of the drill bit 14, detects and analyzes geologic features ahead of the bit 14 which may be qualified as drilling hazards 17. Detection of such hazards 17 may facilitate use of more aggressively penetrating bits 14 such as PDC bits as opposed to roller cone bits. In addition, other drilling parameters may be adjusted to improve ROP due to the ability to timely respond to identified hazards 17 before they may be detrimentally encountered by the bit 14. The acoustic system 15 may look ahead of the bit 14 by at least 100 meters, using propagated acoustic waves 19 to locate changes in acoustic impedance which may represent drilling hazards 17. In addition, bulk resistivity ahead of the bit 14 may also be measured and used to locate drilling hazards 17.

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: Systems and methods for remotely altering operation of a horizontal directional drilling machine provide for remotely disabling movement of a drill string coupled to a cutting head or reamer and, in addition, disabling dispensing of fluid, foam and/or air communicated through the drill string. A lockout signal is transmitted from a portable or hand-manipulatable remote unit operated by an operator remotely situated with respect to the drilling machine. The lockout signal is received at the drilling machine. In response to the received lockout signal, a controller of the drilling machine prevents movement of the drill string and thus the cutting head or reamer. The controller also disables dispensing of fluid, foam and/or air through the drill string in response to the received lockout signal. The controller effects transmission of a verification signal from the drilling machine to the remote location.

Abstract: An apparatus for sending signals downhole during drilling operations uses a main pump to pump mud from a mud pit at a substantially constant flow rate. The bulk of the pumped mud goes downhole to maintain adequate circulation for the drill bit. A bypass pipe is provided with a shut-off valve that is controlled by an electronic controller. By pulsing the opening and closing of the shut-off valve, the volumetric flow downhole is pulsed. The pulse amplitude and duration can be controlled. These pulses in the flow rate are detected by a suitable downhole device such as a flow rate measurement device, a pressure detector or a turbine. The initial “wake-up” pulse is made long enough so that the detection device downhole is always able to detect it. Subsequent to this wake-up pulse, adjustments are made to the pulse duration, in steps of about 2 seconds, for the smallest pulse period that is detectable downhole.