Abstract: An inground isolator and associated method can provide an electrically isolated break in a drill string using electrical insulating members/isolators that are supported by a housing. During drill string operations, the isolators are subject only compressive forces responsive to both extension (pushing) and retraction (pulling) by the drill string. The isolators can be formed from an electrically insulating material such as a ceramic material. An interchangeable inground tool system is described which integrally serves to provide an electrically isolating gap in the drill string.

Abstract: Discriminating between a cable locating signal and a false cable locating signal is described. A reference signal, which contains a locating signal frequency impressed on it, is transmitted in a way which provides for detection of a phase shift between the locating signal and the false locating signal. Based on the phase shift, a receiver is used to distinguish the locating signal from the false locating signal.

Abstract: An arrangement and an associated method are described in which a boring tool is moved through the ground within a given region along a path in which region a cable is buried. The boring tool and the cable transmit a boring tool locating signal and a cable locating signal, respectively. Intensities of the boring tool locating signal and the cable locating signal are measured along with a pitch orientation of the boring tool. Using the measured intensities and established pitch orientation, a positional relationship is determined to relative scale including at least the boring tool and the cable in the region. The positional relationship is displayed to scale in one view. The positional relationship may be determined and displayed including the forward locate point in scaled relation to the boring tool and the cable. Cable depth determination techniques are described including a two-point ground depth determination method.

Abstract: A steering tool is movable by a drill string to form an underground bore along an intended path. A sensing arrangement of the steering tool detects its pitch and yaw orientations at a series of spaced apart positions along the bore, each position is characterized by a measured extension of the drill string. The steering tool further includes a receiver. At least one marker is positioned proximate to the intended path, for transmitting a rotating dipole field to expose a portion of the intended path to the field for reception by the receiver. The detected pitch orientation, the detected yaw orientation and the measured extension of the drill string are used in conjunction with magnetic information from the receiver to locate the steering tool. The steering tool may automatically use the magnetic information when it is available. A customized overall position determination accuracy can be provided along the intended path.

Abstract: Tension monitoring is described using a sensor which may exhibit an offset for which compensation may be provided to produce a zero voltage amplified output or to increase dynamic range. An arrangement determines whether a power reset is responsive to a battery bounce such that an initially-measured system start-up parameter can be retained. The start-up parameter is automatically saved at start-up if the power reset is responsive to a start-up from a shut-down condition. The start-up parameter may be a zero tension amplified output responsive to the sensor offset at zero tension. Protection of a tension data set is provided such that no opportunity for altering the data set is presented prior to transfer of the data set. A housing configuration forms part of an electrical power circuit for providing electrical power to an electronics package from a battery.

Abstract: A portable device and associated method are described for use with a system in which a locating signal is transmitted from within the ground during an operational procedure. The locating signal includes a transmission frequency that is selectable from a group of discrete transmission frequencies in a frequency range and the region includes electromagnetic noise that can vary. The portable device includes a receiver having a bandwidth that includes the transmission frequency range and is operable for measuring the electromagnetic noise in the transmission frequency range to establish a frequency content of the electromagnetic noise for use in selecting one of the discrete transmission frequencies that is subsequently transmitted as the locating signal during the operational procedure. The locating signal can be transmitted from a boring tool, a pullback arrangement or an inground cable. A predicted maximum operational depth for a transmitter can be determined prior to the operational procedure.

Abstract: A boring tool is movable through the ground. A transmitter supported by the boring tool transmits an electromagnetic homing signal. A portable device monitors the electromagnetic homing signal and receives the electromagnetic homing signal in a homing mode for guiding the boring tool to a target position. A processor generates steering commands for guiding the boring tool based on a bore plan in a steering mode such that at least some positional error is introduced without using the electromagnetic homing signal. Switching from the steering mode to the homing mode is based on monitoring of the electromagnetic homing signal as the boring tool approaches the portable device to then guide the boring tool to the target position location in compensation for the positional error. Intermediate target positions are described as well as guiding the boring tool based on the homing signal so long as the portable device receives the signal.

Abstract: A transmitter is part of a cable locating system for use in a region which contains at least first and second in-ground cables, each of which cables includes an electrically conductive component such that, when the first cable is driven at a locating signal frequency to emit a locating signal in an electromagnetic form, the locating signal is coupled to the second cable in a way which causes the second cable to generate a false locating signal in electromagnetic form. The transmitter generates the locating signal frequency for coupling onto the first cable and for transmitting a reference signal, which includes the locating signal frequency such that the reference signal includes a modulation envelope for comparison of the modulation envelope to the locating signal and to the false locating signal at a receiving location to distinguish the locating signal from the false locating signal.

Abstract: An arrangement and an associated method are described in which a boring tool is moved through the ground within a given region along a path in which region a cable is buried. The boring tool and the cable transmit a boring tool locating signal and a cable locating signal, respectively. Intensities of the boring tool locating signal and the cable locating signal are measured along with a pitch orientation of the boring tool. Using the measured intensities and established pitch orientation, a positional relationship is determined to relative scale including at least the boring tool and the cable in the region. The positional relationship is displayed to scale in one view. The positional relationship may be determined and displayed including the forward locate point in scaled relation to the boring tool and the cable. Cable depth determination techniques are described including a two-point ground depth determination method.

Abstract: A steering tool is movable by a drill string to form an underground bore along an intended path. A sensing arrangement of the steering tool detects its pitch and yaw orientations at a series of spaced apart positions along the bore, each position is characterized by a measured extension of the drill string. The steering tool further includes a receiver. At least one marker is positioned proximate to the intended path, for transmitting a rotating dipole field to expose a portion of the intended path to the field for reception by the receiver. The detected pitch orientation, the detected yaw orientation and the measured extension of the drill string are used in conjunction with magnetic information from the receiver to locate the steering tool. The steering tool may automatically use the magnetic information when it is available. A customized overall position determination accuracy can be provided along the intended path.

Abstract: Tension monitoring is described using a sensor which may exhibit an offset for which compensation may be provided to produce a zero voltage amplified output or to increase dynamic range. An arrangement determines whether a power reset is responsive to a battery bounce such that an initially-measured system start-up parameter can be retained. The start-up parameter is automatically saved at start-up if the power reset is responsive to a start-up from a shut-down condition. The start-up parameter may be a zero tension amplified output responsive to the sensor offset at zero tension. Protection of a tension data set is provided such that no opportunity for altering the data set is presented prior to transfer of the data set. A housing configuration forms part of an electrical power circuit for providing electrical power to an electronics package from a battery.

Abstract: A portable locator and method for establishing the location of the cable line in a region which includes at least one generally straight electrically conductive cable line extending across the region from which cable line a locating signal includes a first arrangement for measuring a local flux intensity of the locating signal at a first above ground point within the region with the portable locator in a particular orientation at the first above ground point. A second arrangement uses the local flux intensity to establish a cable line angular orientation which limits the possible directions to the cable line relative to the particular orientation of the portable locator at the above ground point. A third arrangement uses the measured local flux intensity to establish an actual direction of the cable line that is selected from the possible directions based on certain characteristics of the locating signal.

Abstract: A boring tool is movable through the ground. A transmitter supported by the boring tool transmits an electromagnetic homing signal. A portable device monitors the electromagnetic homing signal and receives the electromagnetic homing signal in a homing mode for guiding the boring tool to a target position. A processor generates steering commands for guiding the boring tool based on a bore plan in a steering mode such that at least some positional error is introduced without using the electromagnetic homing signal. Switching from the steering mode to the homing mode is based on monitoring of the electromagnetic homing signal as the boring tool approaches the portable device to then guide the boring tool to the target position location in compensation for the positional error. Intermediate target positions are described as well as guiding the boring tool based on the homing signal so long as the portable device receives the signal.

Abstract: Systems, apparatus and methods are described for purposes of initiating a response to detection of an adverse operational condition involving a system including a drill rig and an inground tool. The response can be based on an uphole sensed parameter in combination with a downhole sensed parameter. The adverse operational condition can involve cross-bore detection, frac-out detection, excessive downhole pressure, a plugged jet indication and drill string key-holing detection. A communication system includes an inground communication link that allows bidirectional communication between a walkover detector and the drill rig via the inground tool. Monitoring of inground tool depth and/or lateral movement can be performed using techniques that approach integrated values. Bit force based auto-carving is described in the context of an automated procedure.

Abstract: A coupling adapter is insertable in at least one joint of a drill string as the drill string is extended from a drill rig. The coupling adapter includes an arrangement for receiving a data signal that is generated by an inground tool and for electromagnetically coupling the data signal onto at least a portion of the drill string that extends from the adapter to the drill rig such that at least some of the drill pipe sections cooperate as an electrical conductor for carrying the data signal to the drill rig. In another feature, a current transformer is resiliently supported to isolate the current transformer from mechanical shock and vibration that is produced by an inground operation that is performed using the drill string. In another feature, a drill string repeater is described.

Abstract: A portable locator and method for establishing the location of the cable line in a region which includes at least one generally straight electrically conductive cable line extending across the region from which cable line a locating signal includes a first arrangement for measuring a local flux intensity of the locating signal at a first above ground point within the region with the portable locator in a particular orientation at the first above ground point. A second arrangement uses the local flux intensity to establish a cable line angular orientation which limits the possible directions to the cable line relative to the particular orientation of the portable locator at the above ground point. A third arrangement uses the measured local flux intensity to establish an actual direction of the cable line that is selected from the possible directions based on certain characteristics of the locating signal.

Abstract: Location determination is performed using a transmitter including an elongated generally planar loop antenna defining an elongation axis. The elongation axis is positioned along at least a portion of a path. A magnetic field is then generated which approximates a dipole field. Certain characteristics of the magnetic field are then determined at a receiving position radially displaced from the antenna elongation axis. Using the determined certain characteristics, at least one orientation parameter is established which characterizes a positional relationship between the receiving position and the antenna on the path. The magnetic field may be transmitted as a monotone single phase signal. The orientation parameter may be a radial offset and/or an angular orientation between the receiving position and the antenna on the path. The antenna of the transmitter may be inserted into a first borehole to transmit the magnetic field to a receiver inserted into a second borehole.

Abstract: Systems, apparatus and methods are described for purposes of initiating a response to detection of an adverse operational condition involving a system including a drill rig and an inground tool. The response can be based on an uphole sensed parameter in combination with a downhole sensed parameter. The adverse operational condition can involve cross-bore detection, frac-out detection, excessive downhole pressure, a plugged jet indication and drill string key-holing detection. A communication system includes an inground communication link that allows bidirectional communication between a walkover detector and the drill rig via the inground tool. Monitoring of inground tool depth and/or lateral movement can be performed using techniques that approach integrated values. Bit force based auto-carving is described in the context of an automated procedure.

Abstract: A coupling adapter is insertable in at least one joint of a drill string as the drill string is extended from a drill rig. The coupling adapter includes an arrangement for receiving a data signal that is generated by an inground tool and for electromagnetically coupling the data signal onto at least a portion of the drill string that extends from the adapter to the drill rig such that at least some of the drill pipe sections cooperate as an electrical conductor for carrying the data signal to the drill rig. In another feature, a current transformer is resiliently supported to isolate the current transformer from mechanical shock and vibration that is produced by an inground operation that is performed using the drill string. In another feature, a drill string repeater is described.

Abstract: A boring tool is movable through the ground. A transmitter supported by the boring tool transmits an electromagnetic homing signal. A portable device monitors the electromagnetic homing signal and receives the electromagnetic homing signal in a homing mode for guiding the boring tool to a target position. A processor generates steering commands for guiding the boring tool based on a bore plan in a steering mode such that at least some positional error is introduced without using the electromagnetic homing signal. Switching from the steering mode to the homing mode is based on monitoring of the electromagnetic homing signal as the boring tool approaches the portable device to then guide the boring tool to the target position location in compensation for the positional error. Intermediate target positions are described as well as guiding the boring tool based on the homing signal so long as the portable device receives the signal.