Abstract: A wireline system and method for removing wireline noise from an electromagnetic wireline tool comprising. The system may comprise a wireline measurement tool, which may comprise a wireline measurement tool body, a wireline cable traversing the tool body, and a wireline signal sensor measuring a signal induced by the wireline cable. The system may further comprise an electromagnetic wireline tool, comprising a wireline tool body, the wireline cable traversing the tool body, and a receiver measuring a signal. A method may comprise running the electromagnetic wireline tool into a wellbore on a wireline, recording wireline signals with a wireline signal sensor on a wireline measurement tool, recording signals with a receiver disposed on the electromagnetic wireline tool, and adjusting recorded signals on the receiver by subtracting filtered recorded signals from the wireline signal sensor.

Abstract: In some embodiments, an apparatus, system, and method may operate to transmit a current from an electrode at a first azimuthal location into a borehole wall in a geological formation, and to receive the first current at a second electrode at a second azimuthal location in the borehole wall. The first and second azimuthal locations are disposed approximately along the same longitudinal location of the borehole wall. The current may be adjusted to maintain a selected voltage profile between the electrodes at the first and second azimuthal locations, and the electrodes at the first and second azimuthal locations may be members of two different sets of azimuthally] differentiated electrodes. Additional apparatus, systems, and methods are disclosed.

Abstract: Various embodiments include apparatus and methods related to finding a position in an underground formation. Apparatus and methods can include receiving signals from a receiver in an underground formation in response to signals generated from transmitting sources, each of the transmitting sources located at a known position; and processing the received signals, based on the signals generated from the transmitting sources, to determine the position of the receiver. A number of techniques can be applied to processing the received signal. Additional apparatus, systems, and methods are disclosed.

Abstract: Systems and methods for corrosion detection of downhole tubulars.

Abstract: Systems and methods for corrosion detection of downhole tubulars.

Abstract: Systems and methods for detection of downhole tubulars.

Abstract: Systems and methods for reducing effects of pipe couplings in electromagnetic log data. A method for corrosion detection comprises disposing an electromagnetic logging tool within a plurality of concentric pipes in a wellbore; obtaining electromagnetic log data along the concentric pipes; and identifying a location of at least one pipe coupling on at least one of the concentric pipes; and processing the electromagnetic log data to determine one or more attribute of the concentric pipes as a function of depth, wherein the processing uses the location of at least one pipe coupling to account for effect of the at least one pipe coupling on the electromagnetic log data.

Abstract: Calibration tools and procedures that provide calibration to galvanic tools can include use of measurement tools to measure resistivity of a calibration box. The resistivity of the calibration box can also be measured by a galvanic tool of interest. The two sets of measurements can be used to calibrate the galvanic tool. Additional apparatus, systems, and methods are disclosed.

Abstract: Methods for detection of pipe characteristics, such as defect detection of downhole tubulars and overall thickness estimation of downhole tubulars, utilizing remote-field eddy current technique.

Abstract: Interrogation tools and methods are used to efficiently locate cable behind casing. The interrogation tool has at least one electromagnetic transmitter and receiver. An electromagnetic field is emitted from inside the tubular, whereby it interacts with the tubular and cable to produce a secondary electromagnetic field. The secondary electromagnetic field is measured by the receiver(s) from at least two different positions inside the tubular to produce corresponding response signals. The interrogation tool then compares the response signals to baseline response signals, whereby the position of the cable is determined. The electromagnetic measurements can be acquired simultaneously or sequentially.

Abstract: Various embodiments include apparatus and methods related to finding a position in an underground formation. Apparatus and methods can include receiving signals from a receiver in an underground formation in response to signals generated from transmitting sources, each of the transmitting sources located at a known position; and processing the received signals, based on the signals generated from the transmitting sources, to determine the position of the receiver. A number of techniques can be applied to processing the received signal. Additional apparatus, systems, and methods are disclosed.

Abstract: Methods and systems for calibrating a corrosion detection tool may comprise: disposing the corrosion detection tool in a calibration area; powering a transmitter and measuring a response on a receiver on the corrosion detection tool; disposing the corrosion detection tool in a test pipe; powering the transmitter and measuring the response on the receiver on the corrosion detection tool while disposed within the test pipe; and determining a multiplicative factor for the receiver. A system may comprise: a corrosion detection tool, wherein the corrosion detection tool comprises: a transmitter; a receiver; and a bucked coil; a test pipe; and an information handling system. A method for operating a corrosion detection tool may comprise: disposing the corrosion detection tool in a tubular string; powering the transmitter; measuring a response on a receiver on the corrosion detection tool while disposed within the tubular string; and calculating properties of the tubular string.

Abstract: Various embodiments include apparatus and methods to make resistivity measurements in a borehole using tool having an array of electrodes operable to provide focused currents, measure corresponding voltages, and measure corresponding voltage differences to determine resistivity. Tools can be configured to operate at a plurality of modes when voltage differences at some frequencies are effectively unreadable. Additional apparatus, systems, and methods are disclosed.

Abstract: Apparatus and methods to visualize pipes of a multi-pipe structure associated with a well site can be implemented in a variety of applications. Responses acquired from signals received in response to transmission of a probe signal from a transmitter operatively disposed within the multi-pipe structure may be processed to determine regions of equivalent metal loss in the pipes. In response to processing the responses, a visualization of the pipes, including defects, may be generated. Additional apparatus, systems, and methods are disclosed.

Abstract: A corrosion detection system for a pipe may include a corrosion detection tool. The corrosion detection tool may include a transmitter and a receiver. The transmitter and receiver have measurements associated with each and these measurements may be used to determine an impedance. Derived constants match a numerical model that is based on the measurements associated with the transmitter and the nominal thickness of the pipe. The information related to the thickness of a pipe surrounding the corrosion detection is based on the derived constants and the impedance. This thickness of the pipe may be used to determine if a section of a pipe has a defect, such as, corrosion.

Abstract: An inspection tool apparatus includes a core having an axial length. The axial length is determined based on a desired depth of inspection radially from the core. A plurality of arms are coupled to and extend radially from the core. The core and the plurality of arms comprise a high permeability magnetic material. The core or at least one of the plurality of arms is wound by a respective coil that is positioned to receive magnetic flux that is passing through the core or at least one of the plurality of arms.

Abstract: Disclosed are methods, systems, and tools for pipe inspection that employ signals from electromagnetic waves emitted towards and scattered in the pipe(s). Various embodiments relate to tool configurations and associated methods for tool operation and signal processing that allow for the reduction or substantial cancellation of the direct signal contribution resulting from direct transmission of the emitted electromagnetic wave from a transmitter to a receiver of the tool.

Abstract: A system comprises one or more electromagnetic coils configured to generate and direct excitation signals toward a plurality of casings in a wellbore and receive response signals based on the excitation signals. The system further comprises one or more processors configured to receive a first response signal from the one or more electromagnetic coils and determine one or more characteristics of a first defect in the plurality of casings using the first response signal and small defect information.

Abstract: Various embodiments include apparatus and methods related to finding a position in an underground formation. Apparatus and methods can include receiving signals from a receiver in an underground formation in response to signals generated from transmitting sources, each of the transmitting sources located at a known position; and processing the received signals, based on the signals generated from the transmitting sources, to determine the position of the receiver. A number of techniques can be applied to processing the received signal. Additional apparatus, systems, and methods are disclosed.

Abstract: Described are systems, devices, and methods for processing Eddy-current response signals acquired in a set of multiple nested pipes, such as, e.g., nested casing strings within a completed wellbore. In various embodiments, time boundaries between time slots within the Eddy-current response signals are determined adaptively based on an input response signal specific to the nested pipes (e.g., one of the measured signals itself). Additional embodiments are disclosed.