Abstract: A method for identifying an artifacts disposed on concentric pipes may comprise disposing an electromagnetic logging tool into a first wellbore, broadcasting an electromagnetic field from a transmitter disposed on the electromagnetic logging tool, energizing a casing with the electromagnetic field, and recording a secondary electromagnetic field from the casing at a plurality of depths and at a plurality of frequencies. The method may further comprise picking a first plurality of artifacts in the first signal, constructing a target value matrix from the first plurality of artifacts, producing a first input matrix from the first signal and a first well plan, and constructing a predictor from the first input matrix and the target value matrix. Additionally, disposing the electromagnetic logging tool into a second wellbore and producing a second plurality of artifacts from the predictor and the second input matrix.

Abstract: A borehole resistivity distribution system includes a cable having an array of transmitters along a shared conductive loop. Each of the transmitters is coupled to a corresponding frequency-dependent material or device. An application of a first drive signal to the cable excites the transmitters, to obtain a first measurement, the first drive signal having a first frequency and a first amplitude. An application of a second drive signal to the cable excites the transmitters, to obtain a second measurement, the second drive signal having a second frequency and a second amplitude. At least the first frequency is different from the second frequency, or the first amplitude is different from the second amplitude. The system further includes a processor coupled to receive the first and second measurements, to derive, based at least in part on the measurements, a resistivity distribution around a borehole.

Abstract: An electromagnetic ranging system and method for location a target well. The electromagnetic ranging system may comprise a modular electromagnetic ranging tool. The electromagnetic ranging tool may comprise at least one transmitter coil and a receiver coil operable to measure at least one component of the electromagnetic field. An information handling system may be in signal communication with the modular electromagnetic ranging tool. A method for electromagnetic ranging of a target wellbore may comprise disposing a modular electromagnetic ranging tool in a wellbore, transmitting an electromagnetic field to the target wellbore from at least one transmitter coil disposed on the modular electromagnetic ranging tool, measuring at least one component of a secondary electromagnetic field, and determining a relative location of the target wellbore from at least measurements by the at least one receiver coil and one or more parameters of the at least one transmitter coil.

Abstract: A rotating coil antenna tool apparatus includes a transmitter coil and a receiver coil that are used for ranging to a target well. The transmitter coil transmits a first electromagnetic signal and the receiver coil receives second electromagnetic signal. At least one of the transmitting coil or the receiver coil is rotating while transmitting or receiving their respective signals. The receiver coil is inhibited from receiving the first electromagnetic signal. A relative distance and/or direction to the target well is determined based on the second electromagnetic signal.

Abstract: Downhole ranging from multiple wellbores. In one example, multiple transmitters and multiple receivers are disposed in multiple wellbores to exchange electromagnetic signals. By implementing a full compensation technique, a computer system determines multiple compensated signals. A compensated signal is determined from a signal received from a first wellbore and a second signal received from a second wellbore. In another example, a first transmitter is disposed in a first wellbore, a first receiver is disposed in a second wellbore, and either a second transmitter or a second receiver is disposed in either the first wellbore or the second wellbore. By implementing partial compensation techniques, a computer system determines compensated signals. Using the compensated signals, the computer system determines a position of a first wellbore relative to a second wellbore, and provides the position.

Abstract: Methods and systems are described that can be used for locating conductive bodies such as wellbore casing or piping disposed below the earth's surface. An electrical current can be excited in a conductive body in each wellbore in a given area to produce a magnetic field, and the magnetic field can be detected by a ranging tool. Location and current parameters can be determined for an estimated number of wellbores producing non-negligible contributions to the magnetic field, and the estimated number of wellbores can be adjusted until the number of contributing wellbores is determined. Location solutions can be returned for each of the contributing wellbores, and the location solutions can be employed to facilitate exploration of drilling applications such as well avoidance, well intersection and/or steam assisted gravity drainage (SAGD) steering operations.

Abstract: A downhole relative positioning system utilizes electromagnetic and survey measurements from a first well to calibrate a formation model, which is then used to improve the interpretation of measurements from a second well. Since the methods described herein utilize a differential approach, even though the exact position of each wellbore may not be accurately identified, their relative positions can be accurately identified.

Abstract: Apparatus, systems, and methods for ranging operate to use a wireline active ranging system to initially determine a relative distance and relative direction from a first well (e.g., ranging well) to a second well (e.g., target well) and an EM azimuthal logging tool to maintain or adjust the distance from the target well while drilling the ranging well. Additional apparatus, systems, and methods are disclosed.

Abstract: Systems and methods that relate to monitoring a subterranean formation using casing centralizers. A system for well monitoring comprising: a casing centralizer comprising arms configured to contact a wellbore when the casing centralizer is installed in a wellbore; and a receiver coupled to the casing centralizer and configured to measure an electrical magnitude of a current injected into a subterranean formation through the arms of the casing centralizer.

Abstract: Hybrid frequency/time-domain modeling may be used to compute the synthetic transient response to an eddy-current pulse for use in a high-dynamic-range and efficient inversion method for pulsed-eddy-current pipe inspection tools. In accordance with some embodiments, frequency-domain response signals are computed for a plurality of frequencies and converted, by frequency-to-time-domain transformation, to a first synthetic transient response signal. A time boundary associated with an onset of spurious oscillations in the first synthetic transient response signal is then automatically determined, and a second synthetic transient response signal beginning at the determined time boundary is determined directly with a time-domain numerical technique. A portion of the first synthetic transient response signal ending at the time boundary may be combined with the second synthetic transient response signal.

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 casing has a plurality of joints of pipe joined by a plurality of casing collars, and an outer surface. A high-frequency alternating current (AC) source electrically is coupled to the casing. A coating of insulating material covers the entire outer surface of the casing. The coating has an opening that exposes a casing portion. The casing and the coating of insulating material define a capacitive electrode having an impedance Zf with a magnitude |Zf| at the frequency of operation f of the high-frequency AC source. Zf is low enough to allow current from the high-frequency AC source to be injected from the casing through the coating of insulating material into a surrounding formation. The casing portion has a resistance R to direct current (DC) with a magnitude that is very large compared to |Zf|.

Abstract: Apparatus, systems, and methods may operate to correct measured voltage data for selected weak differential measurements to provide corrected voltage data. Additional activity may include adjusting the corrected voltage data to remove level shifts in the measured voltage data caused by downhole tool impedance to provide adjusted voltage data, converting the adjusted voltage data into apparent resistivity data, inverting the apparent resistivity data to determine true resistivity values for a geological formation, and operating a controlled device according to the true resistivity values for the geological formation. Additional apparatus, systems, and methods are disclosed.

Abstract: A drill bit analysis and optimization system for use in a wellbore is provided. The system includes a drill bit including a cutter, a sensor that collects a data signal on a surface of the drill bit proximate to the cutter, and a signal processor unit that receives the data signal from the sensor and receives the expected drilling properties from the data reservoir. The processor analyzes the data signal to detect a resistivity profile from the sensor through a formation and optimizes a drilling parameter by comparing actual drilling properties with expected drilling properties.

Abstract: A method and system for wellbore ranging. A method for wellbore ranging may comprise placing a coil antenna in a wellbore, wherein the coil antenna may comprise one or more coil windings, and the coil windings comprise a magnetic material. The method may further comprise measuring a characteristic of an induced electromagnetic field with the coil antenna. A system for wellbore ranging may comprise an electromagnetic ranging tool which may further comprise a coil antenna, wherein the coil antenna comprises one or more coil windings, and wherein the coil windings comprise a magnetic material. The method may further comprise an information handling system, wherein the information handling system may be operable to measure a characteristic of an induced electromagnetic field with the coil antenna.

Abstract: A method and system for electromagnetic ranging of a target wellbore. A method may comprise disposing an electromagnetic ranging tool in a wellbore, energizing a conductive member disposed in the target wellbore to create an electromagnetic field, measuring at least one component of the electromagnetic field from the target wellbore, performing at least two non-axial magnetic field measurements, performing at least one axial magnetic field measurement, calculating a processed non-axial magnetic field measurement using the at least two non-axial magnetic field measurements, calculating an end-of-pipe ratio with the processed non-axial magnetic field measurement and the at least one axial magnetic field measurement, and altering a course of the electromagnetic ranging tool based at least in part from the end-of-pipe ratio. A well ranging system may comprise a downhole assembly, a sensor comprising a first component and a second component, a drill string, and an information handling system.

Abstract: A method for identifying an artifacts disposed on concentric pipes may comprise disposing an electromagnetic logging tool into a first wellbore, broadcasting an electromagnetic field from a transmitter disposed on the electromagnetic logging tool, energizing a casing with the electromagnetic field, and recording a secondary electromagnetic field from the casing at a plurality of depths and at a plurality of frequencies. The method may further comprise picking a first plurality of artifacts in the first signal, constructing a target value matrix from the first plurality of artifacts, producing a first input matrix from the first signal and a first well plan, and constructing a predictor from the first input matrix and the target value matrix. Additionally, disposing the electromagnetic logging tool into a second wellbore and producing a second plurality of artifacts from the predictor and the second input matrix.

Abstract: A logging system includes an electromagnetic logging tool that collects measurements of a subterranean formation as the tool is conveyed along a borehole through the formation. The system further includes a processing system that: generates a first plurality of models of the formation based on at least one first measurement of the formation, the at least one first measurement collected by the tool at a first location of a plurality of locations located along a drilling axis; generates a second plurality of models of the formation based on at least one second measurement of the formation, the at least one second measurement collected by the tool at a second location of the plurality of locations, wherein the second location is adjacent the first location; and selects a model of the first plurality of models based on a spatial continuity of the model with respect to the second plurality of models.

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: Apparatuses and methods are described, such as for aligning downhole measurements. Apparatuses and methods include an arrangement of at least two tilted transmitters and at least one tilted receiver along a longitudinal axis of the tool. A first and second plurality of azimuthal measurements are processed to provide a first and a second plurality of higher order mode signals configured to be time-shifted.