Abstract: A geosignal is calculated based on a signal detected by a multicomponent resistivity tool (101) to facilitate determination of formation properties and infer location of the resistivity tool with respect to formation boundaries. The resistivity tool (101) detects an electromagnetic field response signal (109) at a series of azimuth angles (111) during one tool rotation. The signal measured at each azimuth angle is decoupled to obtain nonzero electromagnetic field tensor components for input into the geosignal calculation. The results of the geosignal calculation for at least a top bin (i.e., an azimuth angle of 360 degrees) and a bottom bin (i.e., an azimuth angle of 180 degrees) are evaluated to determine whether the tool (101) is near a formation boundary. If the tool is determined to be near a formation boundary, the resistivity of the layers of the formation on each side of the detected boundary can be inferred.

Abstract: A method and system for determining a position of a second production wellbore. The method may comprise inducing a first current into a first conductive member with a first source, emitting a first magnetic field generated by the first current from the first conductive member into a formation, inducing a second current into a second conductive member with a second source, emitting a second magnetic field generated by the second current from the second conductive member into the formation, disposing an electromagnetic sensor system into the second production wellbore, recording the first magnetic field with the at least one sensor from the formation, and recording the second magnetic field with the at least one sensor from the formation. The system may comprise a first source, an electromagnetic sensor system, at least one sensor and an information handling system configured to determine the position of the second production wellbore.

Abstract: A downhole tool includes a receive antenna configured to receive a signal from a surrounding formation, and a receive amplifier proximate to and coupled to the receive antenna. The receive amplifier is configured to provide an amplified signal responsive to the signal received by the receive antenna. The downhole tool also includes an electronics carrier, including receive circuitry, coupled to the receive amplifier by a conductor. The electronics carrier is positioned axially away from the receive antenna and the receive amplifier, and the receive circuitry is configured to receive and process the amplified signal.

Abstract: A pixelation-based approach to summarize downhole inversion results acquires inversion solutions and generates an initial model. Each layered solution is pixelated into pixels where each pixel contains the resistivity value of the initial model. A weighted function that weighs pixels according to their proximity to the logging tool may be used to generate the pixelated model to thereby improve accuracy. A statistical summary study is performed to identify the best pixelated model, which is then used to determine one or more formation characteristics.

Abstract: Inductive position sensors for sensing relative position (e.g., relative rotary position) between members are provided. In one example implementation, the inductive position sensor includes a transmit aerial having at least one transmit winding. The inductive position sensor can include a receive aerial having one or more receive windings. The inductive position sensor can include a coupling element operable to be disposed on the second member. The inductive position sensor can include processing circuitry configured to provide one or more signals indicative of the position of the first member relative to the second member based on current induced in the one or more receive windings resulting from an oscillating signal provided to the transmit winding. The inductive position sensor includes at least one electrostatic shield. The electrostatic shield can include a plurality of conductive traces arranged so that no current loops are formed in the electrostatic shield.

Abstract: 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.

Abstract: A down-hole tool includes at least one wall. The at least one wall may include a plurality of joined substantially parallel layers of material, a plurality of pockets defined within the at least one wall, each pocket of the plurality of pockets including a plurality of openings formed in consecutive layers of the plurality of joined substantially parallel layers of material, and a plurality of recesses defined within the at least one wall and between layers of the plurality of joined substantially parallel layers of material, the plurality of recesses defining at least one conduit. The down-hole tool also includes at least one electronic component disposed within a pocket of the plurality of pockets and at least one electrical connection disposed within the at least one conduit.

Abstract: A ranging system using spatially continuous filtering techniques to constrain ranging measurements, thereby improving ranging calculations between a bottom-hole-assembly and at least one target well. By taking advantage of the spatial continuity of the wellbore geometry, a quality check of a ranging measurement is performed using ranging measurements acquired at prior depths. Thus, the methods described herein provide improved ranging and direction estimates, as well as prediction of ranging and direction of the target well ahead of the bottom-hole-assembly.

Abstract: A method of validating a directional survey includes measuring the gravity and magnetic field vectors using a surveying tool and computing an overall statistical distance of the measurement. The statistical distance may be calculated from reference values associated with the surveying tool using corresponding surveying tool codes with error values. In a further aspect, an error covariance matrix may be used to determine whether the new errors m a survey are consistent or not with errors from one or more previous surveys.

Abstract: A magnetic field concentrating or guiding device can include one or more coils, and one or more foil, tape and/or bulk superconductor structures disposed in one or more predetermined positions with relation to the coils. The one or more superconductor structures can form one or more magnetic field carrying regions. During operation, current passing through the one or more coils can generate one or more magnetic fields that are compressed or guided in the magnetic field carrying regions.

Abstract: In an embodiment a method is described which includes emplacing a sample within a measurement cell, wherein two or more electrodes are configured in the measurement cell; introducing a reactive fluid into the measurement cell; reacting the sample with the reactive fluid, wherein reacting the sample with the reactive fluid results in a change in an ion concentration in the reactive fluid; and measuring the resistivity of the reactive fluid using the two or more electrodes, wherein the resistivity is proportional to the ion concentration in the reactive fluid.

Abstract: Evaluation of formation and fracture characteristics based on multicomponent induction (MCI) and multipole sonic logging (MSL) data includes automated calculation of inverted biaxial anisotropy (BA) parameters for the formation by performing an iterative BA inversion operation based on the MCI log data and using a BA formation model that accounts for transfers by axial formation anisotropy to resistivity. The inverted BA parameters and the processed MSL data can be used, in combination, to calculate a quantified value for an identification function, to indicate estimated presence or absence of a fracture in the formation.

Abstract: Methods, systems, devices, and products for performing well logging in a borehole intersecting an earth formation to obtain and transmit an acoustic reflection image of the formation. Methods include identifying a set of features in the acoustic reflection image substantially fitting a pattern, wherein the set of features corresponds to a portion of at least one reflecting structural interface of the formation; and using a representation of the pattern as the compressed representation of the acoustic reflection image. The features may be amplitude peaks in the acoustic reflection image, and the pattern may be a line segment therein that is obtained from the amplitude peaks. Identifying the set of features may include generating a binary image of the amplitude peaks.

Abstract: The highly valuable properties of resistivity and dielectric constant of a geological formation may be determined using an induction measurement, even for a geological formation with bed boundary or dipping effects, using a one-dimensional (1D) formation model. Induction measurements may be obtained in a wellbore through the geological formation using one or more downhole tools. One or more processors may be used to perform an inversion to estimate resistivity and dielectric constant values of the geological formation. The inversion may be performed using the induction measurements and a one-dimensional model that includes a number of geological layers.

Abstract: A method and system for locating one or more bed boundaries. A method for locating one or more bed boundaries may include disposing a downhole tool into a wellbore, measuring wellbore wall resistivity with the downhole tool, extracting a vertical voltage measurement, deconvolving the vertical voltage measurement with an impulse response an apparent resistivity, and calculating a derivative of the apparent resistivity and finding one or more peaks of the derivative to determine the locations of the one or more bed boundaries. A well measurement system for locating one or more bed boundaries may include a downhole tool. The downhole tool may include a pad, an arm, a receiver disposed on the pad, and a transmitter disposed on the pad. The well measurement system may further comprise a conveyance and an information handling system.

Abstract: A calibration method includes determining calibration standards for a reference tool including a reference transmitter and a reference receiver. First and second calibration factors are measured to match a receiver on an electromagnetic measurement tool (the tool to be calibrated) to the reference receiver and to match a transmitter on the electromagnetic measurement tool to the reference transmitter. The electromagnetic measurement tool is deployed in a subterranean wellbore and used to make electromagnetic measurements therein. The measured first and second calibration factors and at least one of the calibration standards are applied to at least one of the electromagnetic measurements to compute a gain calibrated electromagnetic measurement.

Abstract: Inversion of enhanced-sensitivity controlled source electromagnetic data can include combining measured controlled source electromagnetic (CSEM) data onto a common set of virtual receiver positions for each of a plurality of positions of a source along a survey path, determining a steering vector that enhances a sensitivity of the measured CSEM data to a subsurface resistivity variation, and performing an inversion using the measured CSEM data and modeled CSEM data, each having the steering vector applied thereto as a data weight, to better identify the subsurface resistivity variation.

Abstract: A method comprises a) positioning a passive magnetic ranging (PMR) tool in a drilling well that is near a target well that includes a ferromagnetic casing, b) measuring with each of the magnetometers a local magnetic anomaly created by the ferromagnetic casing of the target well so as to generate a plurality of magnetometer readings corresponding to the positions of the magnetometers; c) receiving the plurality of magnetometer readings with the controller; and d) using the received measurements to calculate ranging information, the ranging information including the range and direction from the PMR tool to the target well. The PMR tool may include a ranging collar, a longitudinal array of magnetometers extending along the length of the ranging collar, and a controller, the controller operatively connected to the plurality of magnetometers. The PMR tool may further comprise a radial array of magnetometers positioned radially about the ranging collar.

Abstract: Non-contact type measuring apparatus able to detect a difference in signal intensity by transmitting a radio frequency (RF) signal having a predetermined frequency through one of two coil antennas and receiving an induced RF current signal transmitted via a medium through the other coil antennas and detect conductivity and a variation in characteristic of a non-conductor by comparing the signal intensity with a signal intensity comparison table for each frequency, which is stored in a controller by measuring a signal intensity for each frequency in advance, on the basis of the signal intensity for each frequency. The non-contact type measuring apparatus can accurately measure not only various elements using a characteristic in which conductivity is varied according to total dissolved solid, temperature, and an amount of a conductive medium and permittivity change characteristic of a non-conductor, but also conductivity and variation in characteristic of the non-conductor.

Abstract: A conductivity model is used for a logging tool and surrounding borehole and formation. The conductivity model is separable into a background conductivity model and an anomalous conductivity model for at least one of the formation and the tool. With the conductivity model, background electromagnetic fields and Green's functions corresponding to electromagnetic field signals at one or more receivers are computed for inversion of measured electromagnetic signals to determine adjustable parameters associated with anomalous conductivity. From the inversion, dielectric and other electromagnetic properties of the formation and borehole are determined.

Abstract: In a method for acquiring data of azimuthal acoustic LWD, when an acoustic LWD instrument rotates with a drilling tool at a certain depth, data is acquired by adopting an azimuthal equal-interval mode: a well circumference is divided into m sectors by azimuthal intervals ??, when a toolface angle of the acoustic LWD instrument is located in the kth sector, an acoustic transmitting source is controlled to transmit an acoustic signal, and an acoustic receiver measures the acoustic signal, digitizes it and then stores it as data in the kth sector; and the data is acquired for each sector in turn, and after the data is acquired in each sector for N times, the data acquisition at the current depth is completed. Meanwhile, as the drilling tool rotates and drills, the instrument acquires acoustic data at different depths and processes it to achieve azimuthal acoustic imaging.

Abstract: Systems and methods to investigate multi-pipe structures for detection of corrosion and quantitative assessment of thickness in the multiple pipes can be implemented in a variety of applications. Systems can include a set of transmitters and multiple receivers arranged on a tool structure with variable distances to the transmitters of the set of transmitters, where the receivers are arranged to measure electromagnetic responses from a multi-pipe structure to excitation of the set of transmitters with the tool structure disposed in the multi-pipe structure. The electromagnetic responses may include responses correlated to a near field zone, a transition zone, and a far field zone, where the electromagnetic responses can be processed to recover individual thicknesses of each pipe of the multi-pipe structure. Additional apparatus, systems, and methods are disclosed.

Abstract: An apparatus for applying a magnetic pressure to a work piece includes an inductor configured to be disposed in proximity to the work piece and a controller electrically connected to the inductor. The controller is configured to control a supply of electrical power in order to output a first voltage over a selected frequency range to determine a first frequency that provides a maximum current to the inductor or a second frequency that provides a current within a selected range of the maximum current to the inductor.

Abstract: A system and method for determining formation parameters is provided. The system includes an induction logging tool having a plurality of transmitter coils. The induction logging tool further includes a plurality of receiver coils, each of the receiver coils being spaced apart from the transmitter coils by a predetermined distance and receiving a response signal from the formation. The system includes circuitry coupled to the induction logging tool, the circuitry determining voltages induced in the plurality of receiver coils by the response signal. The circuitry separates real or in-phase portions of the determined voltages from imaginary of ninety degrees out of phase portions of the determined voltages and determines formation parameters using imaginary portions of the measured voltages.

Abstract: Systems and methods for incorporating mandrel current measurements in deep ranging inversion. A method may include introducing a current through a transmitter into a subterranean formation, wherein the transmitter may be a component of an electromagnetic induction tool disposed in a wellbore, wherein the electromagnetic induction tool may comprise the transmitter, a toroid receiver, and a second receiver comprising a coil or electrode, wherein the transmitter, the toroid receiver, and the second receiver may be disposed on a tubular; measuring a first signal utilizing the toroid receiver, wherein the first signal may comprise a tubular current; measuring a second signal utilizing the receiver and determining at least one downhole parameter utilizing the first signal and the second signal.

Abstract: A method and system for mitigating direct coupling. A method of mitigating direct coupling may comprise disposing an electromagnetic sensor system in a wellbore. The electromagnetic sensor system may include a receiver disposed on a conductive body and a gap sub disposed at another location on the conductive body. Exciting an electromagnetic source to inject an electrical current into a formation. Exciting the gap sub to achieve a small current condition at the selected point. Performing a first measurement at a receiver. Interpreting the first measurement to calculate a formation or pipe parameter and using the formation or pipe parameter to adjust at least one parameter of a well operation. A system of mitigating direct coupling may include a conductive body may comprise a gap sub, a controller, a voltage source, a receiver, and an information handling system. The information handling system may be operable to cancel current.

Abstract: A method and system for identifying a target well. A system for identifying a target well may comprise placing an electromagnetic ranging tool in a wellbore, transmitting an electromagnetic field into a formation, inducing an eddy current within a target well, measuring a second electromagnetic field from the target well, calculating a position or an orientation of a transmitter or a receiver relative to another position, and calculating at least one parameter of the target well. An electromagnetic ranging system may comprise an electromagnetic ranging tool and an information handling system. The information handling system may be operable to calculate a position and/or an orientation of a transmitter or a receiver relative to another position on the electromagnetic ranging tool disposed on a borehole assembly, and calculate at least one parameter of a target well from the calculated position or orientation of the transmitter and the receiver.

Abstract: Device, medium and method for generating an image of a subsurface of the earth. The method includes generating an ensemble of realizations (M) based on data related to the subsurface; applying an objective function (O) to members (m) of the ensemble of realizations (m) and corresponding estimated data to estimate a mismatch; selecting a best sensitivity matrix (G) from a plurality of sensitivity matrices associated with the objective function (O) and the ensemble of realizations (M); updating realization parameters (mpr), which are used as input for a forward model (f), to calculate the corresponding estimated data, based on the best sensitivity matrix (G); and generating an image of the subsurface based on (1) the data related to the subsurface of the earth and (2) the forward model (f) with updated realization parameters (mpr).

Abstract: An antenna assembly includes a first leg extending radially over a circumference of a tool, a second leg extending axially over a length of the tool, a third leg radially over a portion of a circumference of the tool, and a fourth leg extending axially over a length of the tool.

Abstract: A method and system for estimating a thickness of at least one casing string in a cased hole may comprise obtaining a plurality of induction measurements from a plurality of channels using a casing inspection tool, computing a quality vector for the plurality of channels, wherein each element of the quality vector is a numeric output, identifying the plurality of channels is a high-quality or a low-quality based at least in part on an evaluation of the quality vector to obtain a high-quality subset of the plurality of channels and a low-quality subset of the plurality of channels, and estimating the thickness of the at least one casing with an inversion using a high-quality subset of the plurality of channels. A system may comprise a multi-channel induction tool and an information handling system. The multi-channel induction tool may comprise at least one transmitter and at least one receiver.

Abstract: A system, downhole tool, and method for lowering the downhole tool having a compact antenna test range (CATR) system into a wellbore in a geological formation to monitor a property downhole in the wellbore via the downhole tool.

Abstract: Apparatus and methods for estimating a value of a resistivity property of an earth formation intersected by a borehole. Apparatus may include a carrier conveyable in the borehole; a tri-axial induction antenna assembly along the carrier; and a magnetically transparent sleeve enclosing the antenna assembly. The antenna assembly includes panels circumferentially arrayed about a portion of the carrier to form at least three collocated antennas. Each panel includes a magnetic core, an axially sensing coil that is transversely wound about the magnetic core, and a laterally sensing coil that is longitudinally wound about the magnetic core. The axially sensing coil of each panel may be electrically connected to the axially sensing coils of the other panels to form an axial antenna. Corresponding lateral coils may be electrically connected to form a lateral antenna. Each panel may be individually removable from the carrier, and assembled together may form a cylinder.

Abstract: A deep measurement electromagnetic antenna array is operated to acquire, formation signals which depend on properties of a geological formation. Formation signals are also acquired from an at-bit resistivity (ABR) sensor, where the ABR sensor comprises a drill bit electrically coupled to a toroid or to multiple electrodes, where the electrodes are separated by at least one gap. Inverting the values of the formation signals transforms the values into an enhanced resistivity measurement of the geological formation, wherein inverting comprises determining at least one of relative distance between layers of the geological formation, relative orientation of the layers to a housing, or a resistivity gradient of the layers, wherein the layers are not locally penetrated by the bit. An ABR sensor together with a deep measurement electromagnetic antenna array improves look-ahead resistivity calculations upon inversion.

Abstract: A method and system for electromagnetic well ranging. The method may comprise receiving signals from one or more receiver coils at different depths in a second wellbore, applying a band-stop filter to the received signals to provide filtered signals, and processing the filtered signals to determine a position of the first wellbore with respect to the second wellbore. An electromagnetic ranging system may comprise a transmitter coil disposed in a second wellbore, a receiver coil disposed in the second wellbore, an information handling system coupled to the transmitter coil and the receiver. The information handling system may be configured to receive signals from one or more receiver coils at different depths in the second wellbore, apply a band-stop filter in a frequency domain to provide filtered signals, and process the filtered signals to determine a position of the first wellbore with respect to the second wellbore.

Abstract: Apparatus and methods operable to determine between a wall of a wellbore penetrating in a subterranean formation and a resistivity tool disposed in the wellbore. One such method includes using an apparent impedance function depending on a frequency variable and a plurality of unknown parameters, at least one of the unknown parameters depending on a formation impedance of the subterranean formation. The method also includes applying a voltage, at each of a plurality of frequency values, between electrodes of a resistivity tool that is disposed in the wellbore. The method also includes measuring, across the electrodes, a plurality of apparent impedance values, each corresponding to a different one of the frequency values. The method still further includes determining the unknown parameters based on the frequency values and the apparent impedance values, and estimating the standoff distance based on an expression that includes at least one of the unknown parameters.

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: Provided are systems and methods for monitoring water cresting in a subsurface formation. Embodiments include, for each of a plurality of locations along a length of a horizontal section of a wellbore extending into a hydrocarbon reservoir of a subsurface formation, advancing an omnidirectional electromagnetic logging tool (ODEMLT) to the location, operating the ODEMLT to transmit (into a portion of the subsurface formation below the horizontal section of the wellbore) an electromagnetic (EM) source signal comprising a multi-frequency waveform, operating the ODEMLT to sense an EM return signal comprising a reflection of the multi-frequency waveform from the subsurface formation, and generating a subset of saturation data for the location corresponding to the sensed EM return signal, and generating, based on the subsets of saturation data, a radargram including a two-dimensional mapping of water saturation within the portion of the subsurface formation.

Abstract: An antenna assembly includes a bobbin positionable about an outer surface of a tool mandrel, and a coil wrapped about an outer bobbin surface of the bobbin and extending longitudinally along at least a portion of the outer bobbin surface. A plurality of ferrites are positioned within a groove defined in the outer surface of the tool mandrel, and the plurality of ferrites extend circumferentially about the outer surface and interpose the tool mandrel and the coil.

Abstract: An electromagnetic sensor for a pipe inspection tool includes a first coil antenna having a wire wrapped about a first core in a first direction, and a second coil antenna axially offset from the first coil and the wire wrapped about a second core in a second direction. A power source is coupled to the wire such that, when excited by the power source, the first coil antenna generates a first magnetic field in a first polar orientation and the second coil antenna generates a second magnetic field in a second polar orientation opposite the first polar orientation.

Abstract: Systems, devices, and methods for evaluating an earth formation. Methods include conveying a tool on a carrier in a borehole, the tool comprising a conducting tubular having a transmitter and receivers disposed thereon in a spaced-apart relationship; inducing a current in the earth formation using the transmitter; measuring with the first receiver a first time-dependent transient electromagnetic (TEM) signal induced by the formation responsive to the current; measuring with a second receiver a second time-dependent TEM signal induced by the formation responsive to the current; and using at least one processor to estimate a corrected time-dependent TEM signal using the first time-dependent TEM signal, the second time-dependent TEM signal, and a correction coefficient estimated as a function of a non-exponentiated ratio of distances rb and rm between the transmitter and the respective receivers.

Abstract: A magnetic field sensor unit for a downhole environment includes an optical fiber, a magnetic field sensor, and an optical transducer. The sensor unit also includes a sealed housing that encloses the magnetic field sensor and the optical transducer. The optical transducer is configured to generate a light beam or to modulate a source light beam in the optical fiber in response to a magnetic field sensed by the magnetic field sensor. Related magnetic field measurement methods and systems deploy one or more of such magnetic field sensor units in a downhole environment to obtain magnetic field measurements due to an emitted electromagnetic field.

Abstract: An electromagnetic (EM) telemetry system includes an EM transmitter configured to transmit EM signals downhole and multiple sensors each configured to communicate with the EM transmitter and with another of the multiple sensors. Each sensor is placed a distance from another sensor along a length of a wellbore in the EM telemetry system. The EM telemetry system also includes a processor configured to select two or more sensors of the multiple sensors based on a signal to noise ratio (SNR) of an EM signal received from the two or more selected sensors, a depth of the EM transmitter, or both.

Abstract: A sensor system for the measurement of a physical parameter, such as temperature or pressure comprises a first, fixed module (5), and a second module (20) positionable proximate to the first. The first module has a measurement coil (6) and a reference coil (7), where the measurement coil forms part of an electrical circuit that is subject to variation by the physical parameter, and the reference coil forms part of a circuit not subject to the physical parameter being measured. The second module has a pair of reading coils (22, 23), each arranged to couple to respective measurement and reference coils, where the reading coils are connectable to signal generation and measurement equipment, and the system is arranged to measure electrical characteristics of the measurement and reference coils via the coupling. It has particular utility in harsh environments such as in wells, where the first module may be fixed, and the second module may be lowered adjacent the first.

Abstract: The present disclosure is directed to an antenna for transfer of information along a drill string. The antenna has an antenna coil having a long side and short side. The antenna coil is adapted to be affixed to the drill string such that the long side of the antenna coil is along the longitudinal axis of the drill string, and the short side is perpendicular to the longitudinal axis of the drill string.

Abstract: Systems, devices, and methods for evaluating an earth formation. Method embodiments may include conveying a carrier in a borehole, the carrier including a conducting tubular having a plurality of transmitters and a receiver non-collocated with the plurality of transmitters; inducing a first current in the earth formation using a first transmitter of the plurality of transmitters; measuring with the receiver a first time-dependent transient electromagnetic (TEM) signal induced by the formation responsive to the first current; inducing a second current in the earth formation using a second transmitter of the plurality of transmitters; measuring with the receiver a second TEM signal induced by the formation responsive to the second current; and using at least one processor to estimate a value of a resistivity property of the earth formation using a bucked signal derived from the first time-dependent TEM signal, the second time-dependent TEM signal, and a bucking coefficient K(t).

Abstract: A method may include drilling a section of a first wellbore and casing a section of a first wellbore. The method may include lowering a downhole receiving system into the first wellbore to a first wellbore depth and drilling at least one section of a second wellbore. In addition, the method may include positioning an EM telemetry system in the at least one section of the second wellbore and transmitting an EM telemetry signal from the EM telemetry system. The method may include receiving the EM telemetry signal with the downhole receiving system.

Abstract: A method for operating an inductive conductivity measuring device that has a transmitting coil with an input and a receiving coil, the transmitting coil and the receiving coil being inductively coupled to one another by an electrically conductive medium. An electrical preset alternating signal is generated and fed to the input of the transmitting coil. The method for operating an inductive conductivity measuring device is improved in that a frequency of a preset alternating signal is varied in a frequency interval, in the frequency interval, a frequency-dependent minimum input impedance at the input of the transmitting coil is determined using a response alternating signal, a minimum frequency of the response alternating signal is determined at the minimum input impedance at the input of the transmitting coil, and a conductivity of the medium is determined using the minimum frequency of the response alternating signal.

Abstract: The disclosed embodiments include systems and methods for multi-frequency focusing signal processing in wellbore logging. In one embodiment, the method includes obtaining a harmonic frequency set to evaluate a resistivity of a formation at a wellbore location, where the harmonic frequency set includes at least one harmonic frequency of a fundamental frequency. The method also includes selecting a waveform from a library of waveforms based on the obtained harmonic frequency set, where the library of waveforms includes a plurality of waveforms having different frequency spectrums. The selected waveform corresponds to a predicted conductivity of the formation. The method further includes generating, based on the selected waveform, a binary waveform for use in evaluating the resistivity of the formation at the wellbore location.

Abstract: A method for estimating an inverted parameter of a subsurface formation includes measuring a first parameter of the subsurface formation and measuring a second parameter of the subsurface formation. The method further includes defining one or more inversion constraints using the second parameter and inverting with a processor the first parameter to generate the inverted parameter of the subsurface formation using the one or more inversion constraints.

Abstract: A method of detecting defects in non-nested tubings or a casing includes acquiring a first set of data from an electromagnetic (“EM”) tool run inside a first of the non-nested tubings. The method further includes calibrating the data to reduce effects from a second of the non-nested tubings, identifying a location of a defect in the first of the non-nested tubings or the casing, and adjusting the data to compensate for eccentricity if the defect is in the casing. The method further includes performing an inversion algorithm on the data, the inversion algorithm developed for a single tubing configuration.