Abstract: A method for making downhole electromagnetic logging while drilling measurements includes rotating an electromagnetic logging while drilling tool in a subterranean wellbore. The logging tool includes a first transmitter and a first receiver deployed on a first sub and a second transmitter and a second receiver deployed on a second sub. Rotating the logging tool causes the first and second subs to rotate at different rates. A plurality of electromagnetic voltage measurements are acquired from the first and second receivers while rotating. The acquired voltage measurements are processed to compute harmonic coefficients which are mathematically rotated to obtain rotated coefficients. Ratios of selected ones of the rotated coefficients are processed to compute gain compensated measurement quantities.

Abstract: Techniques for processing down hole information including detecting bed boundaries are disclosed. In some embodiments, a bottom hole assembly includes a down hole tool and a processing apparatus. The down hole tool includes at least one antenna pair to determine resistivity data during rotation of the down hole tool. The processing apparatus is attached to the down hole tool and includes a machine-readable medium that stores a formation model database comprising multiple formation models. The processing apparatus further includes a processor that executes program code to receive the resistivity data during down hole operation of the down hole tool, and to solve for at least resistivity formation parameters using a selected one of the formation models and a selected portion of the received resistivity data. The processor further executes program code to update the selected formation model based, at least in part, on the resistivity formation parameters.

Abstract: A drilling optimization collar for use proximate a drilling tool within a wellbore includes a fiber optic sensor filament that is sized and configured to fit within a groove formed within the drilling optimization collar. The drilling optimization collar may be a pipe segment that is sized and configured to be installed in a drill string proximate the drilling tool, and may have a plurality of sensor elements. All or a portion of the sensor elements may be formed by discrete segments of the sensor filament, and as such, the sensor filament includes sensor elements that are configured to sense a condition of the wellbore and a load on the drilling optimization collar.

Abstract: A method of processing data from an electromagnetic resistivity logging tool which includes a transmitter coil and a receiver coil is disclosed. The electromagnetic resistivity logging tool is placed at a desired location. The transmitter coil and the receiver coil are positioned at a first azimuthal angle. A signal is transmitted from the receiver coil. The receiver coil then receives a signal. The signal at the receiver coil, a tilt angle of the transmitter coil, a tilt angle of the receiver coil and the first azimuthal angle are then used to calculate a first complex voltage representing at least one component of the received signal.

Abstract: Methods and systems for characterizing a formation are disclosed. A tool is placed in the formation. The tool comprises a perpendicular antenna set and a parallel antenna set. The perpendicular antenna set comprises at least one transmitter antenna oriented perpendicular to at least one receiver antenna and the parallel antenna set comprises at least one transmitter antenna oriented parallel to at least one receiver antenna. Data is obtained from the tool and used to determine a compensated geosignal for each of the perpendicular antenna set and the parallel antenna set. The determined compensated geosignal is used to characterize the formation.

Abstract: An example logging tool includes a tool body characterized by a longitudinal axis and an antenna coupled to the tool body. The logging tool further includes a ferrite element coupled to the tool body proximate at least a portion of the antenna and in a non-parallel orientation with respect to a normal of a plane defined by the antenna.

Abstract: A downhole tool is conveyed within a wellbore extending into a subterranean formation, and then utilized to obtain measurements at multiple different depths of investigation within the subterranean formation relative to the wellbore. The obtained measurements are then compared to assess mobility of oil within the subterranean formation.

Abstract: A method includes obtaining, with a plurality of receivers of a logging tool, a set of induction, multi-spacing, multi-frequency measurements of a plurality of nested casings. The method also includes inverting, with a processor, the set of measurements for magnetic permeability or electrical conductivity. The method further includes calibrating, with the processor, the set of measurements using differences between measured responses of the logging tool, and simulated responses of the logging tool resulting from inverting the set of measurements for the magnetic permeability or electrical conductivity of the plurality of nested casings, to determine a calibrated set of measurements. The method also includes inverting, with the processor, the calibrated set of measurements for thickness of individual casings of the plurality of nested casings, to determine the thickness of the individual casings.

Abstract: An electromagnetic energy transmitter is provided for induced polarization logging with a borehole to surface electromagnetic (BSEM) transmitter. The transmitter is lowered into a well borehole to a desired location in a well borehole to emit electromagnetic energy for the surveys. The transmitter affords more accurate measurements of its position in the well borehole. The transmitter also senses pressure and temperature conditions at its borehole location to provide indications of detected potential problems in the well from the survey or other sources, and to reduce risks and enhance safety and quality of the operations.

Abstract: An example downhole tool may include a tool body and a first conformable sensor coupled to the tool body. The first conformation sensor may include a flexible material, a transmitter coupled to the flexible material, and a plurality of receivers coupled to the flexible material. The downhole tool may further include a control unit with a processor and a memory device coupled to the processor, the memory device containing a set of instructions that, when executed by the processor, cause the processor to output control signals to a first combination of the plurality of receivers corresponding to a first operating mode; and output control signals to a second combination of the plurality of receivers corresponding to a second operating mode.

Abstract: A modular resistivity sensor disposable in a drillstring having a drill bit on a distal end for drilling a wellbore in a formation, includes a sensor body having a longitudinal axis radially offset from a longitudinal axis of the drillstring, one or more transmitting coil antennas disposed along a length of the sensor body, one or more receiving coil antennas disposed along a length of the sensor body, and a calibrating device configured to calibrate signals generated from the receiving coil antennas.

Abstract: Various embodiments include apparatus and methods of sensing and/or mapping a subterranean reservoir. In various embodiments, arrangements of electromagnetic sensors are disposed relative to a subterranean reservoir such that a signal received by electromagnetic sensors of one arrangement, in response to activation of an electromagnetic transmitter, can be analyzed to map the subterranean reservoir. Additional apparatus, systems, and methods are disclosed.

Abstract: A method of monitoring a flood front. The method may comprise installing at least one optical electromagnetic sensor in a wellbore which penetrates an earth formation. The sensor may be a part of an interferometer selected from the group consisting of a Mach Zehnder interferometer and a Michelson interferometer. The method may further comprise inducing an electromagnetic field in the earth formation. A first optical path length in a first optical waveguide of the sensor may increases in response to exposure to the electromagnetic field, and a second optical path length in a second optical waveguide of the sensor may decreases in response to exposure to the electromagnetic field. Additionally, the method may comprise monitoring the flood front by detecting via the sensor the electromagnetic field in the earth formation as the flood front progresses through the earth formation.

Abstract: Systems and methods are provided to enhance logging data images. Some system embodiments include a dowhole tool, at least one sensor, and a processing system. The downhole tool gathers two-dimensional logging data while moving through a borehole. The sensor(s) measure at least one characteristic of the downhole tool's operation or environment, such as tool motion, offset distance, borehole geometry, and/or properties of the borehole fluid. Such characteristics can cause smearing or spreading of the tool's logging data measurements. Accordingly the processing system determines a de-spreading function based at least in part on the measured characteristic(s) and applies the de-spreading function to the two-dimensional logging data to obtain an enhanced logging data image, which can be presented to a user via a user interface.

Abstract: A method for obtaining fully gain compensated propagation measurements includes rotating an electromagnetic logging while drilling tool in a subterranean wellbore. The tool includes first and second transmitters and first and second receivers axially spaced apart from one another in which each of the transmitters and each of the receivers include an axial antenna and collocated first and second transverse antennas. The first and second transverse antennas in the first receiver are rotationally offset by a predefined angle from the first and second transverse antennas in the first transmitter. A plurality of electromagnetic voltage measurements are acquired at the first and second receivers while rotating and processed to compute harmonic coefficients. The harmonic coefficients are mathematically rotated through at least the predefined angle to obtain rotated coefficients. Ratios of selected ones of the rotated coefficients are processed to compute fully gain compensated measurement quantities.

Abstract: A system to determine the placement of multiple RFID tags uses multiple antennae. The RF communication (or NFC) includes read and/or read/write communication with the RFID tags.

Abstract: A logging tool and method for winding a multi-component induction (MCI) antenna is presented. The method eliminates unwanted dipole signals that are created by the voltage drop that takes place in the transmitter. The antenna is made of at least two parts physically separated, one on each side of the mandrel. The winding method is performed in a way that creates at least four windings arranged to eliminate dipole signals attributable to an asymmetric voltage distribution. The midpoint of the conductive wire that for is the antenna windings may be electrically attached to the tool body. This method is suitable for the winding of the cross-components X and Y of the MCI coil arrays.

Abstract: The invention describes a method and system, for mapping non-magnetic soils in terms of their local permittivity and velocity of the traversing electromagnetic waves, by measuring the straight-line attenuation and elapsed time between transmitters and receivers located within tubes inserted into the soil.

Abstract: A disclosed electromagnetic (EM) interferometry system includes a first EM field sensor at a first position in a downhole environment. The system also includes a second EM field sensor at a second position in the downhole environment. The system also includes a processing unit that receives a first EM field measurement from the first EM field sensor and a second EM field measurement from the second EM field sensor. The processing unit derives a response of the first EM field sensor to a virtual EM field source at the second position by cross-correlating the first EM field measurement with the second EM field measurement. The processing unit also performs an inversion process based at least in part on the derived response to obtain a model of subsurface formation properties.

Abstract: An electromagnetic method for obtaining a dip azimuth angle from downhole electromagnetic measurements includes acquiring electromagnetic measurement data in a subterranean borehole from at least one measurement array. The electromagnetic measurement data is processed by a least squares method to obtain the dip azimuth angle. Related systems and apparatuses are also disclosed herein.

Abstract: Methods and systems for obtaining an electrical impedivity and/or resistivity image of a subterranean formation are provided. The electrical impedivity and/or resistivity image can be obtained by determining first formation impedivity data and second formation impedivity data. The first formation impedivity data can be based on a component of the measured impedance data orthogonal a downhole fluid impedance. The second formation impedivity data can be based on an amplitude of the measured impedance data. A combined formation impedivity data can be obtained by combining a portion of the first formation impedivity data based on a first formation impedivity determination process with a portion of the second formation impedivity data based on a second formation impedivity determination process. The electrical impedivity and/or resistivity image of the subterranean formation can then be obtained by using the combined formation impedivity data.

Abstract: A downhole communications arrangement including one or more electromagnetic (EM) devices; and a shield disposed relative to the one or more devices. The shield preventing or reducing passage of one or more EM frequencies and being alterable by one or more selected conditions to allow passage of the one or more frequencies. A method for communicating in a downhole environment.

Abstract: A method for enhanced subsurface hydrocarbon recovery, comprising the use of at least one in-situ broadband antenna to radiate radio frequency energy into the reservoir to heat a target zone. The use of a broadband antenna allows for compensation of growing impedance mismatch between the antenna and the reservoir that occurs during recovery operations.

Abstract: A method of identifying a bed boundary in a subterranean formation by processing data measured by an induction logging tool. An interferometric method compares recorded voltages and/or phases recorded at axially spaced apart receivers on the logging tool. A transmitter is on the logging tool and set between the receivers, where the receivers are equally spaced apart from the transmitter. The transmitter emits a signal having frequencies up to around 50 kHz.

Abstract: A method for obtaining gain compensated electromagnetic logging while drilling propagation measurements includes rotating an electromagnetic logging while drilling tool having first and second transverse transmitter antennas whose moments are orthogonal to one another and first and second transverse receiver antennas whose moments are orthogonal to one another in a subterranean wellbore. Electromagnetic voltage measurements are acquired from the first and second transverse receiver antennas while rotating. The acquired voltage measurements are processed to compute harmonic voltage coefficients. Ratios of selected ones of the harmonic voltage coefficients are in turn processed to compute a gain compensated quantity including a transverse term.

Abstract: A method for obtaining gain compensated propagation measurements includes rotating an electromagnetic logging while drilling tool having at least one axial transmitter antenna, at least one transverse transmitter antenna, at least one axial receiver antenna and at least one transverse receiver antenna in a subterranean wellbore. Electromagnetic voltage measurements are acquired from the axial and transverse receiver antennas while rotating. The acquired voltage measurements are processed to compute harmonic voltage coefficients. Ratios of selected ones of the harmonic voltage coefficients are in turn processed to compute at least one gain compensated quantity including an axial cross term.

Abstract: An electromagnetic energy transmitter is provided for induced polarization mapping with a borehole to surface electromagnetic (BSEM) transmitter. The transmitter is lowered into a well borehole to a desired location in a well borehole to emit electromagnetic energy. An array of receivers spaced over an area of the earth surface senses the induced polarization response to the emitted electromagnetic energy in areas of interest for mapping. Maps are formed of the induced polarization responses sensed by the array of receivers.

Abstract: Electromagnetic (EM) survey processing comprising operating an electronic device to model expected EM field components to be measured by an EM apparatus associated with a subterranean formation, wherein the EM apparatus comprises at least one EM source and at least one EM receiver. The electronic device may be operated to determine one or more ratios of the modeled EM field components. The at least one EM source may be operated to emit an EM signal into the subterranean formation, and the at least one EM receiver may be operated to measure actual EM field components of the EM signal. The electronic device may then be operated to compare the one or more ratios of the modeled EM field components with one or more ratios of the actual EM field components. The one or more ratios of the modeled EM field components may then be updated based on the comparison.

Abstract: A steerable, magnetic dipole antenna for Measurement-While-Drilling (MWD) or Logging-While-Drilling (LWD) applications. The antenna elements use a hole arrangement in addition to grooves in a steel tool body, which is typically a drill collar. This antenna embodiment is extremely robust, meaning that does not significantly reduce the structural integrity of the tool body in which it is disposed. The antenna embodiment is also relatively wear resistant. The resultant magnetic dipole generated by this antenna is also electrically steerable in inclination angle from a common origin. A variable dipole moment inclination angle combined with independently measured tool rotation orientation during normal drilling allows the antenna to generate a magnetic dipole moment that may be directed at any three dimensional angle and from a common origin point at the centroid of the antenna.

Abstract: Methods and systems for determining a standoff between a downhole tool and a geological formation are provided. The standoff may be determined using a standoff measurement system that includes an electrode component, one or more electronics components, one or more transformers, and one or more processor units. When the standoff is expected to be no more than a first distance, a first measurement can be made where both originating and resulting electrical signals are induced at the electrode component. When the standoff is expected to be no less than a second distance, a second measurement can be made where an originating electrical signal is induced at one of the transformers while a resulting electrical signal is induced at the electrode component.

Abstract: A method and system are disclosed herein relating to transmitting data within a borehole. The method and system include having a transmitter disposed at a first location within the borehole and configured to generate a first signal, and more than one receiver and/or repeater disposed at a second location within the borehole. The receivers and/or repeaters are configured to receive the first signal, and further are configured to communicate with each other.

Abstract: Disclosed are systems and methods for analyzing an oil/gas separation process. One disclosed system includes a flow path containing a fluid, a fluid separator coupled to the flow path and having an inlet for receiving the fluid and a discharge conduit for discharging the fluid after having undergone a separation process in the fluid separator, an optical computing device having an integrated computational element configured to optically interact with the fluid before the fluid enters the fluid separator and after the fluid exits the fluid separator and thereby generate optically interacted light, and at least one detector arranged to receive the optically interacted light and generate an output signal corresponding to a characteristic of the fluid.

Abstract: In various embodiments, apparatus and methods are provided to determine formation resistivity associated with a well. Measurements taken using sub-arrays of a tool at different distances of investigation can be used to determine formation resistivity, where the sub-arrays are arranged to make azimuthal related measurements. Separations readings related to resistivity can be generated from signals received from different directions and can be analyzed to characterize validity of a measurement reading. Additional apparatus, systems, and methods are disclosed.

Abstract: A wellbore apparatus may include first and second tubular members joined together in end-to-end relation, the first tubular member having a reduced outer diameter end portion. The wellbore apparatus may further include a removable modular antenna assembly comprising a cylindrical dielectric housing removably positioned on the reduced outer diameter end portion of the first tubular member, at least one antenna coil carried by the cylindrical dielectric housing, and a first electrical connector coupled to the at least one antenna coil. The wellbore apparatus may also include resistivity processing circuitry coupled to the first electrical connector to determine an electrical resistivity of a wellbore based upon the at least one antenna coil.

Abstract: Disclosed herein are electromagnetic resistivity logging systems and methods that employ an antenna configuration having at most two transmitter or receiver antenna orientations that rotate relative to the borehole. The measurements made by this reduced-complexity antenna configuration enable the determination of at least seven components of a coupling matrix, which may be determined using a linear system of equations that express the azimuthal dependence of the measurements. For increased reliability, measurement averaging may be performed in azimuthally spaced bins. The coupling matrix components can then be used as the basis for determining logs of various formation parameters, including vertical resistivity and anisotropy.

Abstract: A method for detection of underground anomalies including in a system of distributed antennas (10), which are leaky transmission lines, disposed in 16 boreholes (12) formed in a ground, a transmitter (14) being connected to one of the antennas (10), and a receiver (16) being connected to another of the antennas (10), injecting an electromagnetic pulse into one of the antennas (10), wherein the pulse gradually leaks out, and wherein if a speed of propagation in the line in which the pulse is injected is faster than a speed of propagation in the ground, a shock wave is transmitted through the ground, called a transmitted signal, and received as a received signal at another of the antennas (10), and wherein an underground anomaly diffracts the shock wave, resulting in a detectable disturbance in the received signal, and locating the anomaly as a function of a time delay of the disturbance relative to the transmitted signal.

Abstract: The present disclosure is related to apparatuses and methods for estimating a phase offset in earth formations. The method may include estimating the phase offset by comparing signals generated and received by a first sub, the second signal being transmitted by a second sub that has been synchronized by the signal generated by the first sub. The signals may be exchanged using a first antenna on the first sub and a second antenna on the second sub. The signals may use a selected frequency. Synchronization may take place without electrical communication between the first and second subs. The method may include compensating for a propagation delay in the signals using the phase offset. The method may include using a time stamp during the synchronization. The apparatus may include a first antenna and a second antenna on first and second subs, respectively, both configured to transmit and receive electromagnetic signals.

Abstract: A method of analyzing a subterranean formation is disclosed. A first signal is transmitted from a transmitter to the formation and a second signal which is a reflection of the first signal is received. A third signal, which is the second signal reversed in time, is then transmitted to the formation. A fourth signal which is a reflection of the third signal from the formation is then received and monitored.

Abstract: An apparatus for measuring a resistivity of a formation comprising an instrumented bit assembly coupled to a bottom end of the apparatus. At least one first electromagnetic wave antenna transmits an electromagnetic wave signal into the formation. At least one second electromagnetic wave antenna located on the instrumented bit assembly and longitudinally spaced apart from the at least one first electromagnetic wave antenna receives the electromagnetic wave signal transmitted through the formation. Electronic circuitry is operably coupled to the at least one second electromagnetic wave antenna to process the received signal to determine a resistivity of the formation proximate the instrumented bit assembly.

Abstract: An apparatus for estimating a property of an earth formation penetrated by a borehole includes: a carrier configured to be conveyed through the borehole; a transmitter antenna disposed at the carrier and configured to emit electromagnetic energy into the earth formation; a controller configured to control electrical current of frequency f transmitted to the transmitter antenna, wherein the transmitted electrical current is non-sinusoidal having a first section with a uniform positive slope and a second section with a uniform negative slope; a receiver antenna configured to receive a signal from the formation indicative of the property; and a processor configured to receive the signal from the receiver antenna and to estimate the property using the received signal.

Abstract: An apparatus for estimating a property of an earth formation penetrated by a borehole includes: a carrier configured to be conveyed through the borehole; a transmitter antenna disposed at the carrier and configured to emit electromagnetic energy; a direction guidance antenna configured to receive the electromagnetic energy from the transmitter antenna and direct the electromagnetic energy into the formation and to receive a signal from the formation indicative of the property; a receiver antenna configured to receive the signal from the direction guidance antenna; and a processor configured to receive the signal from the receiver antenna and to estimate the property using the received signal.

Abstract: Borehole electromagnetic exploration or tomography (EM tomography). An induction type broadband 3-component borehole magnetic measuring sensor can accurately and precisely measure a broadband magnetic field about x, y and z axes using a three-dimensional (3D) model within a borehole by monitoring natural variations in the earth's magnetic field or based on EM tomography using the borehole. The measuring sensor is applicable to energy resource fields such as petroleum and coal, mineral resources fields and civil engineering and environmental fields.

Abstract: The present disclosure relates to a method to determine a volume of clearance surrounding a wellbore. A logging tool is provided. The logging tool may be disposed on a wireline, a drill string, or a wired drill pipe. A formation property is obtained using the logging tool. The formation property may include a voltage, a bulk resistivity, a horizontal resistivity, a vertical resistivity, a porosity, a permeability, a fluid saturation, an NMR relaxation time, a borehole size, a borehole shape, a borehole fluid composition, an MWD parameter, or an LWD parameter. The maximum depth of investigation into the subsurface formation is determined using a model response and a noise level, and the volume of clearance is determined using the determined maximum depth of investigation. The maximum depth of investigation and volume of clearance may be determined even though no boundary layers are detected.

Abstract: The present disclosure relates to systems and methods for conducting an electromagnetic borehole-to-surface survey of a formation surrounding a borehole. Such methods include deploying a dipole transmitter into the borehole to a depth of investigation, deploying an array of electromagnetic receivers outside of the wellbore, and measuring a response of the formation at the array of electromagnetic receivers deployed outside of the wellbore, for example at the surface. From the response of the formation a property of the formation can be determined based on the response of the formation measured at the array of electromagnetic receivers. For the scenario of a cased well, a local reference receiver may be added at a location proximate the borehole to measure the effective magnetic moment of the transmitter inside the casing, and normalize the formation response in order for a more accurate determination of a formation characteristic, such as resistivity.

Abstract: A system and method for effective estimation of properties of a formation using acoustic array processing is disclosed. An acoustic tool is directed to a zone of interest in the formation and generates a first signal. Real data corresponding to the first signal is then received. One or more basic parameters are provided as input. The basic parameters may include parameters relating to the acoustic tool or parameters relating to the zone of interest. A time semblance shear slowness and a frequency semblance shear slowness are determined using the basic parameters. A mask is then selected using the determined time semblance and frequency semblance shear slowness values and used to isolate a dispersion curve. A shear slowness value is selected from the dispersion curve and quality control is performed on the selected shear slowness value.

Abstract: Disclosed dielectric logging tools and methods employ three or more receive horn antennas positioned between at least two transmit antennas, which can also be horn antennas. The logging tools can operate in the range between 100 MHz and 10 GHz to provide logs of formation permittivity, formation conductivity, standoff distance, and electrical properties of material in the standoff gap. Logs of water-saturated porosity and/or oil movability can be readily derived. The presence of additional receive antennas offers a significantly extended operating range, additional depths of investigation, increased measurement accuracy, and further offers compensation for tool standoff and mudcake effects. In both wireline and logging while drilling embodiments, at least some disclosed dielectric logging tools employ a set of three axially-spaced receive antennas positioned between pairs of axially-spaced transmit antennas.

Abstract: An apparatus for making resistivity measurements near a drill bit includes a tool body, a transmitter deployed on the tool body, a receiver deployed on the tool body and at an axial distance from the transmitter, and a transmitting signal coupler coupled to the transmitter antenna and the receiver. The transmitter generates electrical signals and converts the electrical signals into electromagnetic signals to be transmitted. The receiver measures the amplitudes and phases of the electromagnetic signals received from the transmitter. The transmitting signal coupler couples a portion of the electrical signals from the transmitter antenna and measures the amplitudes and phases of the coupled electrical signals. Amplitude attenuation and phase shift between the electromagnetic signals received at the receiver and the electrical signals coupled at the transmitting signal coupler are computed for calculating resistivity.

Abstract: An apparatus for making formation resistivity measurements near a drill bit includes a tool body, a toroidal antenna deployed on the tool body near the drill bit, a coupler coupled to the toroidal antenna, a transmitter circuit coupled with the toroidal antenna via the coupler to provide voltage signals to energize the toroidal antenna, a receiver circuit coupled with the toroidal antenna via the coupler to couple electrical current signals flowing in the toroidal antenna to the receiver circuit, and a controller and processor module coupled to the transmitter circuit and the receiver circuit to control the measurement operation and calculate formation resistivity. Formation resistivity is computed based on the voltage signals to energize the toroidal antenna and the measured electrical current signals flowing in the toroidal antenna. A corresponding method for making formation resistivity measurements near a drill bit is also provided.

Abstract: A high-frequency data and/or power transmission system suitable for downhole use including signal/power couplers, transmission line segments and signal repeaters. Signals and power are/is transmitted between couplers and/or between couplers and repeaters by means of electromagnetic resonance coupling. In at least a portion of the system, the transmission line segments form parallel data paths and the repeaters provide crossover capability between the data/power paths, thereby significantly improving reliability. The invention also includes methods of transmitting data and/or distributing high-frequency power through a downhole transmission system including multiple data/power paths and multiple crossovers wherein a fault location in one data/power path is bypassed by routing data and/or power to a parallel data/power path by means of electromagnetic resonance coupling.

Abstract: A logging tool and method to make subsurface measurements is disclosed, wherein the tool is placed within a borehole penetrating a formation. The tool has a transmitter antenna and a receiver antenna spaced apart along a longitudinal axis of the tool, and at least one of the transmitter or receiver antennas has a dipole moment that is non-coaxial with the longitudinal axis of the tool. The at least one non-coaxial antenna can rotate relative to the other antenna. Energy is transmitted from the transmitter antenna and a signal associated with the transmitted energy is measured at the receiver antenna while the at least one non-coaxial antenna rotates relative to the other antenna.