The disclosure presents processes that utilize collected resistivity data, for example, from an ultra-deep resistivity tool located downhole a borehole. In some aspects, each slice of resistivity data can generate multiple distribution curves that can be overlaid offset resistivity logs. In some aspects, an analysis can be performed to identify trends in the distribution curves that can be used to identify approximate locations of subterranean formation surfaces, shoulder beds, obstacles, proximate boreholes, and other borehole and geological characteristics. As the number of distribution curves generated increase, the confidence in the analysis also increases. In some aspects, the number of distribution curves can be twenty, one hundred, one hundred and one, or other counts of distribution curves. In some aspects, the resistivity data can be used to generate two or more synchronized view perspectives of a specific location along the borehole, where each view perspective uses the same focus area.

Methods to operate an NMR tool, methods to simulate a numerically-controlled oscillator of an NMR tool in real time, and downhole NMR tools are presented. A method to operate an NMR tool includes determining a phase shift of a sinusoidal wave, determining a number of look-up tables and a number of terms of Taylor Expansions performed to obtain a value corresponding to a phase angle of the phase shift, and separating the phase angle into a first component and a second component. The method also includes obtaining a first value corresponding to the first component from the number of look-up tables, performing the number of terms of Taylor Expansions on the second component to obtain a second value corresponding to the second component, combining the first value and the second value to obtain the value of the phase angle, and generating the sinusoidal wave having the phase shift.

Methods to operate an NMR tool, methods to simulate a numerically-controlled oscillator of an NMR tool in real time, and downhole NMR tools are presented. A method to operate an NMR tool includes determining a phase shift of a sinusoidal wave, determining a number of look-up tables and a number of terms of Taylor Expansions performed to obtain a value corresponding to a phase angle of the phase shift, and separating the phase angle into a first component and a second component. The method also includes obtaining a first value corresponding to the first component from the number of look-up tables, performing the number of terms of Taylor Expansions on the second component to obtain a second value corresponding to the second component, combining the first value and the second value to obtain the value of the phase angle, and generating the sinusoidal wave having the phase shift.

Data filtering and processing techniques for generating improved wellbore resistivity maps are contemplated. In some aspects, a process of the disclosed technology includes steps for receiving a plurality of measurement sets, wherein each measurement set includes electromagnetic field data associated with a geologic formation, performing an inversion on each of the plurality of measurement sets to generate a corresponding plurality of formation profiles, and applying a filter to each of the formation profiles to generate a plurality of profile clusters. In some aspects, the process can further include steps for selecting a representative cluster from among the profile clusters for use in generating a wellbore resistivity map. Systems and machine-readable media are also provided.

Data filtering and processing techniques for generating improved wellbore resistivity maps are contemplated. In some aspects, a process of the disclosed technology includes steps for receiving a plurality of measurement sets, wherein each measurement set includes electromagnetic field data associated with a geologic formation, performing an inversion on each of the plurality of measurement sets to generate a corresponding plurality of formation profiles, and applying a filter to each of the formation profiles to generate a plurality of profile clusters. In some aspects, the process can further include steps for selecting a representative cluster from among the profile clusters for use in generating a wellbore resistivity map. Systems and machine-readable media are also provided.

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.

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.

Methods for determining water-filled porosity using a general volumetric mixing law and the measurements of a dielectric tool are described. The water-filled porosity estimates are used to obtain water salinity estimates and the optimal parameters of the volumetric mixing law. These estimates are in turn used to generate novel quality indicators.

Methods for determining water-filled porosity using a general volumetric mixing law and the measurements of a dielectric tool are described. The water-filled porosity estimates are used to obtain water salinity estimates and the optimal parameters of the volumetric mixing law. These estimates are in turn used to generate novel quality indicators.

Circuits that employ selective solid-state isolation of circuit elements can include solid-state switches, such as back-to-back Field Effect Transistor (FET) pairs, and isolated gate drive electronics adapted to operate the solid-state switches in order to selectively decouple certain circuit elements. The isolated solid-state switches can be placed in series to achieve higher standoff voltages, and can be configured for low on resistance and short switching times. The gate drive electronics can include electrical isolation components adapted to enhance standoff voltages and reduce electrical noise at the selectively isolated circuit elements.