Abstract: A housing defines a through passage along its length and is configured to support a group of electrical isolators surrounding the through passage to form an electrically isolating break in a drill string such that each isolator of the group of isolators is subject to no more than a compressive force responsive to extension and retraction of the drill string. The housing defines a housing cavity to receive an electronics package having a signal port and is configured for electrical connection of the signal port across the electrically isolating break. A housing lid can cooperate with a main housing body to define elongated slots for purposes of enhancing the emanation of a locating signal. A housing arrangement can support electrical connections from an electronics package to bridge an electrically isolating gap.

Abstract: A housing defines a through passage along its length and is configured to support a group of electrical isolators surrounding the through passage to form an electrically isolating break in a drill string such that each isolator of the group of isolators is subject to no more than a compressive force responsive to extension and retraction of the drill string. The housing defines a housing cavity to receive an electronics package having a signal port and is configured for electrical connection of the signal port across the electrically isolating break. A housing lid can cooperate with a main housing body to define elongated slots for purposes of enhancing the emanation of a locating signal. A housing arrangement can support electrical connections from an electronics package to bridge an electrically isolating gap.

Abstract: A housing defines a through passage along its length and is configured to support a group of electrical isolators surrounding the through passage to form an electrically isolating break in a drill string such that each isolator of the group of isolators is subject to no more than a compressive force responsive to extension and retraction of the drill string. The housing defines a housing cavity to receive an electronics package having a signal port and is configured for electrical connection of the signal port across the electrically isolating break. A housing lid can cooperate with a main housing body to define elongated slots for purposes of enhancing the emanation of a locating signal. A housing arrangement can support electrical connections from an electronics package to bridge an electrically isolating gap.

Abstract: A housing defines a through passage along its length and is configured to support a group of electrical isolators surrounding the through passage to form an electrically isolating break in a drill string such that each isolator of the group of isolators is subject to no more than a compressive force responsive to extension and retraction of the drill string. The housing defines a housing cavity to receive an electronics package having a signal port and is configured for electrical connection of the signal port across the electrically isolating break. A housing lid can cooperate with a main housing body to define elongated slots for purposes of enhancing the emanation of a locating signal. A housing arrangement can support electrical connections from an electronics package to bridge an electrically isolating gap.

Abstract: An accelerometer module is supported within an interior passage of a transmitter housing of a transmitter that is itself receivable within an inground housing of an inground tool to perform an inground operation which subjects the transmitter to mechanical shock and vibration. An accelerometer housing of the module includes an exterior periphery that is receivable in the interior passage of the transmitter. A resilient damping foam can be supported to dispose the foam between the accelerometer housing and the transmitter housing such that the foam cooperates with the accelerometer housing to form a complex mass-spring-damper system that exhibits a resonant frequency which is controllable. An accelerometer cartridge of the module can include a mass that is at least five times the mass of an original accelerometer cartridge. In one feature, the accelerometer cartridge can include a mass of at least 20 grams for a one inch diameter transmitter housing.

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: A housing defines a through passage along its length and is configured to support a group of electrical isolators surrounding the through passage to form an electrically isolating break in a drill string such that each isolator of the group of isolators is subject to no more than a compressive force responsive to extension and retraction of the drill string. The housing defines a housing cavity to receive an electronics package having a signal port and is configured for electrical connection of the signal port across the electrically isolating break. A housing lid can cooperate with a main housing body to define elongated slots for purposes of enhancing the emanation of a locating signal. A housing arrangement can support electrical connections from an electronics package to bridge an electrically isolating gap.

Abstract: A housing defines a through passage along its length and is configured to support a group of electrical isolators surrounding the through passage to form an electrically isolating break in a drill string such that each isolator of the group of isolators is subject to no more than a compressive force responsive to extension and retraction of the drill string. The housing defines a housing cavity to receive an electronics package having a signal port and is configured for electrical connection of the signal port across the electrically isolating break. A housing lid can cooperate with a main housing body to define elongated slots for purposes of enhancing the emanation of a locating signal. A housing arrangement can support electrical connections from an electronics package to bridge an electrically isolating gap.

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: 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: 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: A housing defines a through passage along its length and is configured to support a group of electrical isolators surrounding the through passage to form an electrically isolating break in a drill string such that each isolator of the group of isolators is subject to no more than a compressive force responsive to extension and retraction of the drill string. The housing defines a housing cavity to receive an electronics package having a signal port and is configured for electrical connection of the signal port across the electrically isolating break. A housing lid can cooperate with a main housing body to define elongated slots for purposes of enhancing the emanation of a locating signal. A housing arrangement can support electrical connections from an electronics package to bridge an electrically isolating gap.

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: A housing defines a through passage along its length and is configured to support a group of electrical isolators surrounding the through passage to form an electrically isolating break in a drill string such that each isolator of the group of isolators is subject to no more than a compressive force responsive to extension and retraction of the drill string. The housing defines a housing cavity to receive an electronics package having a signal port and is configured for electrical connection of the signal port across the electrically isolating break. A housing lid can cooperate with a main housing body to define elongated slots for purposes of enhancing the emanation of a locating signal. A housing arrangement can support electrical connections from an electronics package to bridge an electrically isolating gap.

Abstract: A hydraulic pulse valve for use in downhole tools includes a split ring seal to limit the fluid flow available to shift a poppet in the valve from an open position to a closed position. The split ring seal provides relatively long and repeatable pressure pulses, which improve the effectiveness of the hydraulic pulse valve for borehole applications.

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: 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: A housing defines a through passage along its length and is configured to support a group of electrical isolators surrounding the through passage to form an electrically isolating break in a drill string such that each isolator of the group of isolators is subject to no more than a compressive force responsive to extension and retraction of the drill string. The housing defines a housing cavity to receive an electronics package having a signal port and is configured for electrical connection of the signal port across the electrically isolating break. A housing lid can cooperate with a main housing body to define elongated slots for purposes of enhancing the emanation of a locating signal. A housing arrangement can support electrical connections from an electronics package to bridge an electrically isolating gap.

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: This invention discloses a valve that generates a hydraulic negative pressure pulse and a frequency modulator for the creation of a powerful, broadband swept impulse seismic signal at the drill bit during drilling operations. The signal can be received at monitoring points on the surface or underground locations using geophones. The time required for the seismic signal to travel from the source to the receiver directly and via reflections is used to calculate seismic velocity and other formation properties near the source and between the source and receiver. This information can be used for vertical seismic profiling of formations drilled, to check the location of the bit, or to detect the presence of abnormal pore pressure ahead of the bit. The hydraulic negative pressure pulse can also be used to enhance drilling and production of wells.