Abstract: An apparatus, method, and system for determining the propagation delay for a downhole wire and/or for monitoring the integrity of a downhole wire. The apparatus includes a first tool component and a second tool component spaced apart from the first tool component and communicatively coupled by a wire. The tool components include impedance altering devices configured to alter, for a predetermined period of time, either the source impedance at a first termination point of the wire and/or the load impedance at a second termination point of the wire sufficient to generate a characteristic signal reflection upon the transmission of a signal along a length of the wire between the first tool component and the second tool component.

Abstract: A method for calibrating a downhole tool may comprise disposing a downhole tool in a borehole, transmitting a signal from a master module disposed on the first device to a module disposed on the second device, transmitting a return signal from the module to the master module, receiving the return signal with the master module, measuring a tone enabled delay for the signal to travel from the master module to the module, and determining a time delay of a return signal to travel from the module to the master module. A well measurement system may comprise a downhole tool. The downhole tool may further comprise a first device and a master module disposed on the first device, wherein the master module may comprise a master transmitter and a master receiver. In examples, the downhole tool may further comprise a second device and a module disposed on the second device.

Abstract: This disclosure presents an apparatus and system for lowering the cost of implementing a downhole sensor system using attachable collars. In some aspects, the attachable collar includes a transmitter component, while supporting electronics are included with a main collar, thereby reducing the cost of the attachable collar. The supporting electronics can send a transmission signal, a control signal, a synchronization clock signal, a selected transmission frequency, a sensor orientation and selection, and other instructions to the transmitter in the attachable collar. The receiver in the main collar can receive the output, as reflected by the subterranean formation, and transform the output to subterranean formation evaluation measurements. The measurements can be communicated to other systems. In some aspects, the attachable collar can include the receiver and the main collar can include the transmitter.

Abstract: A method of fabricating a ferrite for use in a resistivity logging tool includes providing an uncured ferrite material, and pressing the uncured ferrite material into a channel to form the ferrite. The channel is defined on a surface of a bobbin associated with the resistivity logging tool, and the channel can be arcuate and extend at an angle offset from a central axis of the bobbin. The uncured ferrite material is then cured in place within the channels on the bobbin.

Abstract: A measurement device can be provided for a tubular string of a drilling subsystem. The measurement device can include a transmitter and a receiver. A cover can be applied to at least one of the receiver or the transmitter. While at least one of the receiver or the transmitter is covered by the cover, an amount of crosstalk can be measured. The cover can be removed from the measurement device. Subsequent to removing the cover from the measurement device, an air-hang response of the receiver and the transmitter can be measured in an air-hang configuration of the tubular string. A corrected air-hang response of the measurement device can be determined by subtracting the amount of crosstalk from the air-hang response.

Abstract: A measurement device can be provided for a tubular string of a drilling subsystem. The measurement device can include a transmitter and a receiver. A cover can be applied to at least one of the receiver or the transmitter. While at least one of the receiver or the transmitter is covered by the cover, an amount of crosstalk can be measured. The cover can be removed from the measurement device. Subsequent to removing the cover from the measurement device, an air-hang response of the receiver and the transmitter can be measured in an air-hang configuration of the tubular string. A corrected air-hang response of the measurement device can be determined by subtracting the amount of crosstalk from the air-hang response.

Abstract: A drilling system, comprising a drill string; and a ranging tool mounted on the drill string, the ranging tool comprising a magnetic sensor pair comprising a first magnetic sensor and a second magnetic sensor mounted radially opposite one another on the ranging tool, wherein each of the magnetic sensors is structured and configured to detect at least a radial component and a tangential component of a magnetic field; a rotatable assembly, comprising a motor structured and arranged to actuate rotation of the magnetic sensor pair around the drill string; and an electronics package connected to at least one of the magnetic sensor pair, and the motor, wherein the electronics package comprises a controller and a wireless telemetry device.

Abstract: A drilling system, comprising a drill string; and a ranging tool mounted on the drill string, the ranging tool comprising a magnetic sensor pair comprising a first magnetic sensor and a second magnetic sensor mounted radially opposite one another on the ranging tool, wherein each of the magnetic sensors is structured and configured to detect at least a radial component and a tangential component of a magnetic field; a rotatable assembly, comprising a motor structured and arranged to actuate rotation of the magnetic sensor pair around the drill string; and an electronics package connected to at least one of the magnetic sensor pair, and the motor, wherein the electronics package comprises a controller and a wireless telemetry device.

Abstract: An electronics carrier to be disposed in a downhole tool is provided. The electronics carrier includes a chassis, and a receiver processing component disposed on the chassis. The receiver processing component is communicatively coupled to one or more receiver sensors, and the receiver processing component includes a receiver pre-amplifier. A transmitter processing component is disposed on the chassis. The transmitter processing component is communicatively coupled to one or more transmitter sensors. A shield is disposed on the chassis to prevent cross-talk between the transmitter processing component and the receiver processing component.

Abstract: A compact sub assembly and a method for forming a deep antenna. The assembly may comprise a look-ahead deep transmitter is attached at about one end of the compact sub assembly, and a shallow transmitter is attached to the compact sub assembly and positioned adjacent to the look-ahead deep transmitter. A method of forming a deep antenna may comprise positioning a look-ahead deep transmitter adjacent to a shallow transmitter at about one end of a compact sub assembly, and connecting the look-ahead deep transmitter to a switching module through one or more deep switches, connecting the shallow transmitter to the switching module through one or more shallow switches, and closing the one or more deep switches and the one or more shallow switches to activate the look-ahead deep transmitter and the shallow transmitter to form the deep antenna.

Abstract: A method for calibrating a downhole tool may comprise disposing a downhole tool in a borehole, transmitting a signal from a master module disposed on the first device to a module disposed on the second device, transmitting a return signal from the module to the master module, receiving the return signal with the master module, measuring a tone enabled delay for the signal to travel from the master module to the module, and determining a time delay of a return signal to travel from the module to the master module. A well measurement system may comprise a downhole tool. The downhole tool may further comprise a first device and a master module disposed on the first device, wherein the master module may comprise a master transmitter and a master receiver. In examples, the downhole tool may further comprise a second device and a module disposed on the second device.

Abstract: This disclosure presents an apparatus and system for lowering the cost of implementing a downhole sensor system using attachable collars. In some aspects, the attachable collar includes a transmitter component, while supporting electronics are included with a main collar, thereby reducing the cost of the attachable collar. The supporting electronics can send a transmission signal, a control signal, a synchronization clock signal, a selected transmission frequency, a sensor orientation and selection, and other instructions to the transmitter in the attachable collar. The receiver in the main collar can receive the output, as reflected by the subterranean formation, and transform the output to subterranean formation evaluation measurements. The measurements can be communicated to other systems. In some aspects, the attachable collar can include the receiver and the main collar can include the transmitter.

Abstract: A logging tool and a method for in-situ, independent calibration of receiver amplifier electronics separately from transmitter electronics. A logging tool can perform in-situ gain and phase calibration on one or more receiver assemblies, each consisting of at least a receiver amplifier electronics and a receiver antenna, and based on a calculated gain and phase of the receiver assembly, determine the true antenna amplitude and phase associated with a measurement made by the receiver assembly. The logging tool can perform in-situ crosstalk measurement and calibration, by determining a crosstalk matrix for all of the receiver assemblies and for each receiver assembly, removing the crosstalk interference from the measurement made by the receiver assembly.

Abstract: A modular downhole logging system includes a transmitter module having a local frequency, wherein the transmitter module transmits interrogation signals into a formation based on the local frequency. The downhole system also includes a receiver module axially-spaced from the transmitter module and that receives response signals corresponding to the interrogation signals, wherein the receiver module includes sampling logic and sync estimation logic. The sync estimation logic is configured to perform sync estimation operations including estimating the local frequency of the transmitter module based on analysis of response signal Fourier transform results corresponding to different frequencies. The sampling logic/clock is configured to sample the response signals based on the estimated local frequency of the transmitter module, wherein a processor derives formation property values using the sampled response signals.

Abstract: An electronics carrier to be disposed in a downhole tool is provided. The electronics carrier includes a chassis, and a receiver processing component disposed on the chassis. The receiver processing component is communicatively coupled to one or more receiver sensors, and the receiver processing component includes a receiver pre-amplifier. A transmitter processing component is disposed on the chassis. The transmitter processing component is communicatively coupled to one or more transmitter sensors. A shield is disposed on the chassis to prevent cross-talk between the transmitter processing component and the receiver processing component.

Abstract: A downhole system includes a first module having a transmitter that transmits at least one sync control signal. The system also includes a second module having a sync module with a direct digital synthesizer (DDS). The sync module analyzes the at least one sync control signal to identify at least one of a sync frequency and a sync phase. The DDS adjusts a local receiver clock based on the identified at least one of a sync frequency and a sync phase.

Abstract: An antenna assembly includes a tool mandrel having a tool axis; a first coil antenna including a first plurality of windings wrapped about the tool mandrel, wherein the first coil antenna is arranged in a first orientation and wherein portions of the first plurality of windings are wrapped about the tool mandrel at a first winding angle defined with respect to the tool axis; and a second coil antenna co-located with the first coil antenna and including a second plurality of windings wrapped about the tool mandrel, wherein the second coil antenna is arranged in a second orientation opposite the first orientation, wherein portions of the second plurality of windings are wrapped about the tool mandrel at a second winding angle defined with respect to the tool axis and wherein a difference between a loop area of the first coil antenna and a loop area of the second coil antenna is less than 25%.

Abstract: A method of fabricating a ferrite for use in a resistivity logging tool includes mixing a ferrite powder with a binder to provide a mixture, and pressing the mixture into a mold to form the ferrite. The mold exhibits a specific geometry corresponding to a channel defined on an inner surface of a bobbin associated with the resistivity logging tool, and the channel is arcuate and extends at an angle offset from a central axis of the bobbin. At least one of a length, a width, and a thickness of the ferrite is then adjusted to manipulate a magnetic permeability of the ferrite in a direction of a magnetic field passing through the ferrite.

Abstract: An apparatus, method, and system for determining the propagation delay for a downhole wire and/or for monitoring the integrity of a downhole wire. The apparatus includes a first tool component and a second tool component spaced apart from the first tool component and communicatively coupled by a wire. The tool components include impedance altering devices configured to alter, for a predetermined period of time, either the source impedance at a first termination point of the wire and/or the load impedance at a second termination point of the wire sufficient to generate a characteristic signal reflection upon the transmission of a signal along a length of the wire between the first tool component and the second tool component.

Abstract: In some embodiments, an apparatus and a system, as well as methods, include sampling a received signal that represents a downhole signal source, at a sampling frequency and for a sampling duration, to provide a sampled signal. Further activity may comprise detecting a frequency of a component of the sampled signal from inspection of a frequency domain representation of the sampled signal. Further activity may comprise adjusting at least one operating frequency for the downhole tool such that the at least one operating frequency is outside a frequency range from the frequency of the component of the sampled signal. Additional methods, apparatus, and systems are disclosed.