Abstract: Certain logging method and system embodiments obtain multi-component signal measurements from an electromagnetic logging tool conveyed along a borehole through a formation, and invert the measurements for a single frequency using an anisotropic formation model having at least dip, horizontal and vertical resistivity, and horizontal and vertical permittivity, as parameters. A resulting log is provided to represent a position dependence of at least one of said parameters or a formation property derived from at least one of said parameters. Illustrative formation properties include water saturation, rock type, and presence of pyrite or other such materials having anisotropic polarization. Inversions may be performed on measurements acquired at other frequencies to determine a representative dispersion curve for further characterization of the formation.

Abstract: Device, system, and method embodiments provide fluid front monitoring via permanent, casing-mounted electromagnetic (EM) transducers. One or more casing strings have one or more transmit antennas that each encircle a casing string and one or more receive antennas that similarly encircle the casing string, with at least one receive antenna oriented differently from at least one transmit antenna to provide sensitivity to at least one cross-component signal. A processor unit derives an estimated distance to a fluid front, and may further determine a direction and orientation of the fluid front for display to a user. Signals from an array of transmit and receive antennas may be combined, optionally with signals from other boreholes, to locate and track multiple points on the fluid front. In response to the determined location and progress of the front, the processor unit may further provide control settings to adjust injection and/or production rates.

Abstract: Disclosed systems and methods provide automated log quality monitoring, thereby enabling fast, on-site determination of log quality by logging engineers as well as re-assurance to interpreters faced with geologically-improbable features in the logs. Such uses can provide early detection of logging issues, increase confidence in acquired logs, reduce unnecessary duplication of effort, and improve the reputation of the logging company. In at least some embodiments, log monitoring software applies a comparison function to axially-spaced (and/or azimuthally-spaced) sensors. The comparison function can be, inter alia, cross-correlation, mutual information, mean-square error, and ratio image uniformity, each of which can be determined as a function of a sliding window position to indicate regions wherein the log quality falls below a threshold value. It is not necessary for the log sensors to be of the same type, e.g., resistivity image sensors.

Abstract: A downhole telemetry well system transmits data at a high rate inside a tubular pipe by encoding signals on a Stoneley wave. Telemetry devices for the Stoneley mode are implemented in short pipe joints inserted at various intervals between the tubulars. Each telemetry device includes Stoneley transducers, which may act as a transmitter, receiver, or repeater. The Stoneley telemetry devices transmit and receive the Stoneley waves making up the carrier of the signal. The Stoneley telemetry devices may be powered by on-board batteries or via some remote power source.

Abstract: Air-motion powered devices may be used to automatically maintain a target tire inflation pressure or to equip vehicle wheels with additional functionality. One illustrative device embodiment is an air compressor that attaches to the wheel of a vehicle, moving with the wheel as the wheel rotates. An action member extends from the compressor body to be acted upon by air through which the vehicle moves, the air causing motion of the action member relative to the compressor body to power the air compressor. Another illustrative device embodiment is an energy harvester that attaches to the wheel of a vehicle to move with the wheel as the wheel rotates. An action member attached to the base of the energy harvester is acted upon by air through which the vehicle moves, causing motion of the action member relative to the base to generate electrical power for sensors, lights, or other transducers.

Abstract: Air-motion powered devices may be used to automatically maintain a target tire inflation pressure or to equip vehicle wheels with additional functionality. One illustrative device embodiment is an air compressor that attaches to the wheel of a vehicle, moving with the wheel as the wheel rotates. An action member extends from the compressor body to be acted upon by air through which the vehicle moves, the air causing motion of the action member relative to the compressor body to power the air compressor. Another illustrative device embodiment is an energy harvester that attaches to the wheel of a vehicle to move with the wheel as the wheel rotates. An action member attached to the base of the energy harvester is acted upon by air through which the vehicle moves, causing motion of the action member relative to the base to generate electrical power for sensors, lights, or other transducers.

Abstract: Air-motion powered devices may be attached to vehicle wheels to harvest energy from the air through which the vehicle passes. One illustrative energy harvester embodiment includes a body that attaches to a wheel of a vehicle to move with the wheel as the wheel rotates. An action member attached to the body is acted upon by air through which the vehicle moves, causing the action member to move relative to the body. The motion of the action member optionally drives a generator to generate electrical power. An illustrative method embodiment which may be implemented by a wheel-attached energy harvester includes: receiving with the action member an aerodynamic force from air through which the vehicle moves; deriving from the aerodynamic force motion of the action member relative to the body; and converting said motion into electrical power. The electrical power may be supplied to sensors, lights, or motors.

Abstract: An illustrative method that includes positioning an acoustic transducer downhole substantially parallel to a borehole wall, thereby creating a fluid layer between the wall and the acoustic transducer, and measuring an acoustic impedance at the surface of the acoustic transducer at a resonance frequency of the fluid layer, thereby determining an acoustic impedance of the formation.

Abstract: A downhole telemetry well system transmits data at a high rate inside a tubular pipe by encoding signals on a Stoneley wave. Telemetry devices for the Stoneley mode are implemented in short pipe joints inserted at various intervals between the tubulars. Each telemetry device includes Stoneley transducers, which may act as a transmitter, receiver, or repeater. The Stoneley telemetry devices transmit and receive the Stoneley waves making up the carrier of the signal. The Stoneley telemetry devices may be powered by on-board batteries or via some remote power source.

Abstract: Various micro-sonic density imaging-while-drilling systems and methods are disclosed. In at least some forms, the micro-sonic logging tool is embodied in a drill collar having at least one stabilizer blade. One or more acoustic transmitters are set in a distal face of the stabilizer blade to generate acoustic waves. One or more receivers can also be set in the distal face of the stabilizer blade to detect P-waves and S-waves that have propagated through the formation making up the borehole wall. Processing circuitry measures the velocity or slowness of the acoustic waves and optionally associates the measured values with a spot on the borehole wall as identified. Multiple transmitters can be used if it is desired to obtain compensated measurements. The tool can further include a fluid cell to measure acoustical properties of the borehole fluid, which can be used to convert the formation slowness measurements into density measurements.

Abstract: Air-drag powered devices are provided for automatically maintaining a target inflation pressure or for equipping vehicle wheels with additional functionality. One illustrative device embodiment is an air compressor that attaches to the wheel of a vehicle to turn with the wheel as the vehicle moves. A drag member extends from the body of the air compressor to alternately present opposing surfaces to the air through which the vehicle passes. The air drag on the member thus creates an alternating drag force that powers the air compressor. Another illustrative device embodiment is an energy harvester that attaches to the wheel of a vehicle to turn with the wheel as the vehicle moves. A drag member attached to the base of the energy harvester presents alternating surfaces to the air through which the vehicle passes to derive a reciprocating motion suitable for generating electricity usable for powering wheel-mounted sensors or lights.

Abstract: Air-drag powered devices are provided for automatically maintaining a target inflation pressure or for equipping vehicle wheels with additional functionality. One illustrative device embodiment is an air compressor that attaches to the wheel of a vehicle to turn with the wheel as the vehicle moves. A drag member extends from the body of the air compressor to alternately present opposing surfaces to the air through which the vehicle passes. The air drag on the member thus creates an alternating drag force that powers the air compressor. Another illustrative device embodiment is an energy harvester that attaches to the wheel of a vehicle to turn with the wheel as the vehicle moves. A drag member attached to the base of the energy harvester presents alternating surfaces to the air through which the vehicle passes to derive a reciprocating motion suitable for generating electricity usable for powering wheel-mounted sensors or lights.

Abstract: Certain logging method and system embodiments obtain multi-component signal measurements from an electromagnetic logging tool conveyed along a borehole through a formation, and invert the measurements for a single frequency using an anisotropic formation model having at least dip, horizontal and vertical resistivity, and horizontal and vertical permittivity, as parameters. A resulting log is provided to represent a position dependence of at least one of said parameters or a formation property derived from at least one of said parameters. Illustrative formation properties include water saturation, rock type, and presence of pyrite or other such materials having anisotropic polarization. Inversions may be performed on measurements acquired at other frequencies to determine a representative dispersion curve for further characterization of the formation.

Abstract: A disclosed downhole optical imaging tool includes a light source and a camera enclosed within a tool body having at least two sidewall windows. A first window transmits light from the light source to a target region in the borehole, while a second window passes reflected light from the target region to the internal camera. The target region is spaced along the borehole away from the second window in a direction opposite the first window. In some embodiments, this configuration is provided by angling the first and second windows with respect to the sidewall, or by shaping the windows to cast and receive light from a “forward” direction. Some tool embodiments include motion and/or orientation sensors that are employed by a processor to combine separately captured images into a panoramic borehole image. It can be employed during drilling operations employing air or a substantially transparent liquid as a drilling fluid.

Abstract: An illustrative method that includes positioning an acoustic transducer downhole substantially parallel to a borehole wall, thereby creating a fluid layer between the wall and the acoustic transducer, and measuring an acoustic impedance at the surface of the acoustic transducer at a resonance frequency of the fluid layer, thereby determining an acoustic impedance of the formation.

Abstract: Device, system, and method embodiments provide fluid front monitoring via permanent, casing-mounted electromagnetic (EM) transducers. One or more casing strings have one or more transmit antennas that each encircle a casing string and one or more receive antennas that similarly encircle the casing string, with at least one receive antenna oriented differently from at least one transmit antenna to provide sensitivity to at least one cross-component signal. A processor unit derives an estimated distance to a fluid front, and may further determine a direction and orientation of the fluid front for display to a user. Signals from an array of transmit and receive antennas may be combined, optionally with signals from other boreholes, to locate and track multiple points on the fluid front. In response to the determined location and progress of the front, the processor unit may further provide control settings to adjust injection and/or production rates.

Abstract: Various micro-sonic density imaging-while-drilling systems and methods are disclosed. In at least some forms, the micro-sonic logging tool is embodied in a drill collar having at least one stabilizer blade. One or more acoustic transmitters are set in a distal face of the stabilizer blade to generate acoustic waves. One or more receivers can also be set in the distal face of the stabilizer blade to detect P-waves and S-waves that have propagated through the formation making up the borehole wall. Processing circuitry measures the velocity or slowness of the acoustic waves and optionally associates the measured values with a spot on the borehole wall as identified. Multiple transmitters can be used if it is desired to obtain compensated measurements. The tool can further include a fluid cell to measure acoustical properties of the borehole fluid, which can be used to convert the formation slowness measurements into density measurements.

Abstract: A method and apparatus provide a time-dependent calibration to essentially eliminate pipe effect in pulse-induction logging while drilling. Use of two receivers to provide calibration and measurement information allows determination of formation properties in a downhole environment while eliminating the effect of tool effects.

Abstract: A disclosed downhole optical imaging tool includes a light source and a camera enclosed within a tool body having at least two sidewall windows. A first window transmits light from the light source to a target region in the borehole, while a second window passes reflected light from the target region to the internal camera. The target region is spaced along the borehole away from the second window in a direction opposite the first window. In some embodiments, this configuration is provided by angling the first and second windows with respect to the sidewall, or by shaping the windows to cast and receive light from a “forward” direction. Some tool embodiments include motion and/or orientation sensors that are employed by a processor to combine separately captured images into a panoramic borehole image. It can be employed during drilling operations employing air or a substantially transparent liquid as a drilling fluid.

Abstract: An apparatus for measuring one or more earth formation properties during applications including formation evaluation and geosteering applications is provided. The apparatus includes: an elongated body; at least one recessed portion on a periphery of the elongated body; an electrically conductive coil forming a closed loop, at least a portion of the coil extending through the at least one recessed portion; and a u-shaped magnetically permeable and non-conductive material disposed between the coil and the at least one recessed portion, the u-shaped material partially surrounding the coil in the at least one recessed portion. A system for measuring one or more properties of an earth formation is also provided.