Abstract: A method and system for determining properties of a pipe string using multi-channel induction measurements. The method may comprise disposing a multi-channel induction tool in a cased hole, obtaining a multi-channel measurement, forming a log from the multi-channel measurement, extracting at least one abnormality that corresponds to known metal thickness, performing a search to find a set of pipe material properties that minimize a mismatch between the abnormality and a simulated response, and inverting the log to estimate the set of pipe material properties at one or more depth points using the set of pipe material properties. The system may comprise a multi-channel induction tool. The multi-channel induction tool may comprise at least one transmitter, at least one receiver, and an information handling system.

Abstract: A downhole sensor deployment assembly includes a body attachable to a completion string and one or more arms pivotably coupled to the body. A sensor pad is coupled to each arm and movable from a retracted position, where the sensor pad is stowed adjacent the completion string, and an actuated position, where the sensor pad is extended radially away from the completion string. One or more actuators are pivotably coupled to the body at a first end and pivotably coupled to a corresponding one of the one or more arms at a second end, the one or more actuators being operable to move the sensor pad to the actuated position. One or more sensor devices are coupled to the sensor pad for determining a resistivity of a formation, the one or more sensor devices comprising at least one of a sensing electrode, a transceiver, and a transmitter.

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.

Abstract: A method and a system for estimating a pipe property for a plurality of nested pipes. The method may comprise determining the pipe property from the plurality of measurements, wherein the pipe property identifies a feature in the wellbore, forming a pre-computed table of responses for the at least one channel comprising a plurality of points that sample the pipe property, and performing a model-based inversion to estimate the pipe property using the plurality of measurements, the nominal properties of the pipes, and a fast forward model based on the pre-computed table of responses. A system may comprise an electromagnetic logging tool and an information handling system. The electromagnetic logging tool may comprise a transmitter, wherein the transmitter is a first coil and is operable to transmit an electromagnetic field, and a receiver, wherein the receiver and is operable to measure the electromagnetic field.

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 includes a set of one or more electromagnetic (EM) field sensors deployed in a borehole formed in a downhole formation, wherein the set of EM field sensors provides sensitivity to EM fields. The system also includes an EM field source that emits an EM field into the downhole formation. The system also includes a data processing system that receives measurements collected by the set of EM field sensors in response to the emitted EM field. The data processing system models the subsurface EM field based on the received measurements and identifies a plurality of flood fronts corresponding to fluid approaching the borehole from the injection wells, and adjusts injection rates to prevent injection fluid breakthrough.

Abstract: A method for detecting corrosion may comprise placing an electromagnetic logging tool into a wellbore, emitting an electromagnetic field from a transmitter, energizing a casing with the electromagnetic field to produce an eddy current, recording the eddy current from the casing with a receiver, creating a well log from the recorded eddy current, removing a collar signal from the well log to obtain a collar-removed signal, calculating a baseline signal from the collar-removed signal, subtracting the baseline signal from the collar-removed signal to obtain a baseline-subtracted signal, calculating an artifact-removed signal with the baseline-subtracted signal, and displaying the artifact-removed signal. A system for detecting corrosion may comprise an electromagnetic logging tool, wherein the electromagnetic logging tool comprises a transmitter and a receiver. The system may further comprise an information handling system.

Abstract: Techniques are described that enables controlling the TNULL characteristic of a self-compensated oscillator by controlling the magnitude and direction of the frequency deviation versus temperature, and thus, compensating the frequency deviation.

Abstract: A method and system for identifying a deformation. The method may comprise disposing an electromagnetic logging tool in a pipe string, performing a logging operation with the electromagnetic logging tool, transmitting an electromagnetic field from a transmitter, energizing the casing string with the electromagnetic field to produce an eddy current, measuring the eddy current with at least one receiver, processing the measurements of the eddy current to find a point-wise eccentricity between the casing string and the pipe string, identifying a zone with the deformation based at least in part on the point-wise eccentricity, determining at least one characteristic of the deformation, and making a wellbore decision related to an integrity of the casing string based on the at least one characteristic of the deformation or the point-wise eccentricity. The system may comprise an electromagnetic logging tool which may comprise a transmitter and at least one receiver.

Abstract: A method includes generating a set of sub-images of a subsurface formation based on measurement values acquired by a plurality of sensors corresponding to one or more signals that have propagated through the subsurface formation, wherein each of the set of sub-images correspond to one of the plurality of sensors. The plurality of sensors are on a tool in a borehole, wherein each of the plurality of sensors are at different spatial positions with respect to each other. The method also includes generating a combined image by aligning the set of sub-images based on the measurement values, wherein the aligning of the set of sub-images is independent of acceleration of the tool during tool motion.

Abstract: A method for determining the activation of an expandable sand screen may comprise disposing an electromagnetic (EM) detection tool into a wellbore. The EM detection tool may comprise at least one transmitter and at least one receiver. The method may further comprise transmitting an EM field from the one or more transmitters into the expandable sand screen to energize the expandable sand screen and form an eddy current, recording a voltage of the eddy current with the at least one receiver, and determining an activation state of the expandable sand screen based at least partially on the voltage of the eddy current.

Abstract: Systems and methods for detection of downhole tubulars.

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]curent 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: Systems and methods for handling idle websites on a Web server are disclosed. The duration between requests for a website application is monitored and compared to an idle time-out value. The idle time-out value may be a user-selected value that is the same for all website applications or an idle time-out value selected for a group of worker processes. When the idle time-out value is reached, all inactive memory allocations for the website application are paged-out. When a request for the website application is later received, memory for the website application is paged-in so that the request can be processed.

Abstract: A through-casing formation monitoring system may include a casing string positioned within a wellbore, a power source electrically coupled to the casing string, a voltage sensor electrically coupled to an inner surface of the casing string such that the voltage sensor allows a continued operation of the wellbore, a fiber optic cable coupled to an electro-optical transducer within the voltage sensor, and an optical interrogation system configured to measure an electric potential applied to the electro-optical transducer via the fiber optic cable.

Abstract: Apparatus and methods to investigate a multiple nested conductive pipe structure can be implemented in a variety of applications. An electromagnetic pulsed tool disposed in the multiple nested conductive pipe structure in a wellbore can make a set of log measurements and provide a measured log at different depths in the multiple nested conductive pipe structure. The total thickness of the multiple nested conductive pipes can be determined at each depth in the measured log using a remote field eddy current look-up curve. The remote field eddy current look-up curve can be correlated to a remote field eddy current regime in time-domain associated with time decay response. Additional apparatus, systems, and methods are disclosed.

Abstract: According to at least some embodiments, a method of processing inversion results corresponding to a plurality of parameters of a subterranean formation includes obtaining measurements of the subterranean formation from a multi-component induction (MCI) tool. The method further includes inverting the measurements to determine a first estimated value of a parameter of the plurality of parameters. The method further includes determining at least a second estimated value of the parameter, and assessing a quality of the inverted measurements by comparing the first estimated value with the at least a second estimated value.

Abstract: Systems and methods for detection of downhole tubulars.

Abstract: A system includes a set of one or more electromagnetic (EM) field sensors deployed in a borehole formed in a downhole formation, wherein the set of EM field sensors provides directional sensitivity to EM fields. The system also includes an EM field source that emits an EM field into the downhole formation. The system also includes a data processing system that receives measurements collected by the set of EM field sensors in response to the emitted EM field. The data processing system models the subsurface EM field based on the received measurements and identifies a plurality of flood fronts at different azimuthal positions relative to the borehole.

Abstract: A system for locating water floods, in some embodiments, comprises: multiple transducers for coupling to a borehole casing to inject current into a formation within which the casing is disposed; and multiple electrodes, each of the electrodes coupled to a different one of the multiple transducers when coupled to the casing, wherein each of the multiple transducers is used to determine a potential between the casing and a corresponding one of the multiple electrodes to which the transducer is coupled, wherein the potentials from the multiple transducers are used to determine a water flood location.