Abstract: Aspects of the subject technology relate to systems, methods, and computer-readable media for corrosion analysis using magnetic flux leakage measurements. The present technology can magnetic flux leakage data obtained by a magnetic flux leakage tool placed in a pipe within a wellbore and convert the magnetic flux leakage data into image data. Further, the present technology can provide the image data to a machine learning model. The machine learning model is configured to identify one or more physical parameters associated with corrosion present on the pipe.

Abstract: Aspects of the subject technology relate to systems, methods, and computer-readable media for accounting for artifacts in pipe measurements made by an electromagnetic pipe inspection tool. Measurements gathered in a plurality of pipes across different depth points are accessed. Initial estimates of an attribute associated with the plurality of pipes are made for each pipe and a total estimate of the attribute for the plurality of pipes as a whole are made across the different depth points. Corresponding initial estimates of the attribute for each pipe are filtered to remove an artifact present in at least one of the corresponding initial estimates while the total estimate is preserved. Corresponding final estimates of the attribute for each pipe are determined based on both the measurements and corresponding filtered initial estimates of the attribute for each pipe. Integrity of each pipe can be determined based on the corresponding final estimates of the attribute.

Abstract: Systems and methods to generate radial resistivity profiles of formations using combined measurements from omni-directional and pad-type tools are described. Measurements from a pad-type resistivity tool are obtained along a wellbore drilled through a subsurface formation. Measurements from an omni-directional resistivity tool (e.g., a dual laterolog) are also obtained. The measurements from the pad-type and omni-directional tools are then combined and used to generate a radial resistivity profile of the formation.

Abstract: A method for estimating a thickness for each of a plurality of nested tubulars may comprise disposing an electromagnetic (EM) logging tool in a wellbore. The method may further comprise transmitting an electromagnetic field from the transmitter into one or more tubulars to energize the one or more tubulars with the electromagnetic field thereby producing an eddy, forming a measurement log from the plurality of measurements, and solving a first inverse problem with uniform priors to obtain a first set of estimated tubular parameters. The method may further comprise designing a data-driven prior based on the first set of estimated tubular parameters, solving a second inverse problem with the data-driven prior to obtain a second set of estimated tubular parameters, and using the second set of estimated tubular parameters to make informed decisions on the integrity of the well casings.

Abstract: Aspects of the subject technology relate to systems and methods for identifying values of mud and formation parameters based on measurements gathered by an electromagnetic imager tool through machine learning. One or more regression functions that model mud and formation parameters capable of being identified through an electromagnetic imager tool as a function of possible tool measurements of the electromagnetic imager tool can be generated using a known dataset associated with the electromagnetic imager tool. One or more tool measurements obtained by the electromagnetic imager tool operating to log a wellbore can be gathered. As follows, one or more values of the mud and formation parameters can be identified by applying the one or more regression functions to the one or more tool measurements.

Abstract: A method for correcting borehole images may include acquiring a raw data image of a formation using a downhole tool that takes one or more measurements and processing the raw data image through a machine learning model to form a corrected image. The method may further include displaying the corrected image and identifying one or more formation properties based at least in part on the corrected image.

Abstract: A system may include an electromagnetic (EM) logging tool for inspecting downhole tubulars. The EM logging tool may include a mandrel, at least one low-frequency transmitter coil disposed on the mandrel, at least one-low frequency receiver coil disposed on the mandrel, and at least one-high frequency sensor configured to measure one or more electromagnetic properties of a tubular.

Abstract: Fiber optic sensors are described for detecting the operational position of a downhole moveable device. In one example, an electric or magnetic field is emitted into the wellbore and interacts with the moveable assembly, thereby producing a secondary electric or magnetic field. The secondary field is detected by a fiber optic sensor which produces a corresponding response signal. The response signal is then processed in a variety of ways to determine the operational position of the moveable device. In another example, the operational position is determined using fiber optic temperature or acoustic sensors. A temperature or acoustic vibration reading is acquired before and after actuation of the moveable device. The two readings are then compared to determine the operation position of the moveable device.

Abstract: A system may include an electromagnetic (EM) logging tool for inspecting downhole tubulars. The EM logging tool may include a mandrel, at least one low-frequency transmitter coil disposed on the mandrel, at least one-low frequency receiver coil disposed on the mandrel, and at least one-high frequency sensor configured to measure one or more electromagnetic properties of a tubular.

Abstract: Aspects of the subject technology relate to systems and methods for identifying a mud angle associated with an electromagnetic imager tool based on tool measurements made during operation of the electromagnetic imager tool. Tool measurements made by an electromagnetic imager tool operating to log a wellbore in a formation can be gathered. The tool measurements can be decomposed into two quantities along a plurality of candidate mud angles for the electromagnetic imager tool. As follows, a mud angle associated with the electromagnetic imager tool can be identified from the plurality of candidate mud angles based on an amount of correlation between the two quantities for each of the plurality of candidate mud angles.

Abstract: Methods and devices used to calibrate EM corrosion detection tools may estimate the effects of the presence of a core on measurements to enable more accurate corrosion detection in the well line. The methods may involve sending voltages to a core of a well tool disposed in the well line to obtain signals while the core is in a saturated and unsaturated state. Subsequent measurements using the core may be calibrated using a constant resulting from the division of the signals achieved at the core in the saturated and unsaturated states.

Abstract: The disclosed embodiments include systems and methods to image a borehole. In one embodiment, a borehole imaging system having a borehole imaging tool and a processor is provided. The borehole imaging tool includes a magnetic field source and an array of electrode buttons. The borehole imaging tool also includes a galvanic source operable to inject an electrical current through one or more electrode buttons of the array of electrode buttons into the formation. The processor is operable to determine a differential voltage between at least two electrode buttons of the array of the electrode buttons, and determine the current through the one or more electrode buttons. The processor is also operable to determine a magnetic susceptibility and a resistivity of the formation based on the differential voltage and the current, respectively, and construct a visual representation of the formation based on the resistivity and the magnetic susceptibility of the formation.

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. A test setup or library can provide a set of small defect log measurements. Processing circuitry can process the set of log measurements to generate thickness estimations of the multiple nested conductive pipes and processing circuitry can process the set of small defect log measurements to generate small defect thickness estimations. Processing circuitry can solve a system of equations involving the thickness estimations and the small defect thickness estimations to generate thickness variations for the multiple nested conducted pipes over the different depths. Additional apparatus, systems, and methods are disclosed.

Abstract: Methods and devices used to calibrate EM corrosion detection tools may estimate the effects of the presence of a core on measurements to enable more accurate corrosion detection in the well line. The methods may involve sending voltages to a core of a well tool disposed in the well line to obtain signals while the core is in a saturated and unsaturated state. Subsequent measurements using the core may be calibrated using a constant resulting from the division of the signals achieved at the core in the saturated and unsaturated states.

Abstract: A substance saturation sensing method includes making a resistivity measurement of a formation proximate to a well with a logging tool prior to installation of a casing string in the well. After the casing string is installed in the well, a first set of measurements of the formation is made with a monitoring system to generate a measured response. A set of calibration values is calculated based on the first set of measurements to produce a resistivity that matches the resistivity measurement. A second set of measurements of the formation is made with the monitoring system during or after saturating of a substance occurs in the formation. At least one parameter indicative of the saturating of the substance in the formation is determined based on the second set of the measurements and the set of calibration values.

Abstract: Aspects of the subject technology relate to systems and methods for identifying values of mud and formation parameters based on measurements gathered by an electromagnetic imager tool through machine learning. One or more regression functions that model mud and formation parameters capable of being identified through an electromagnetic imager tool as a function of possible tool measurements of the electromagnetic imager tool can be generated using a known dataset associated with the electromagnetic imager tool. One or more tool measurements obtained by the electromagnetic imager tool operating to log a wellbore can be gathered. As follows, one or more values of the mud and formation parameters can be identified by applying the one or more regression functions to the one or more tool measurements.

Abstract: Aspects of the subject technology relate to systems and methods for identifying values of mud and formation parameters based on measurements gathered by an electromagnetic imager tool through machine learning. One or more regression functions that model mud and formation parameters capable of being identified through an electromagnetic imager tool as a function of possible tool measurements of the electromagnetic imager tool can be generated using a known dataset associated with the electromagnetic imager tool. One or more tool measurements obtained by the electromagnetic imager tool operating to log a wellbore can be gathered. As follows, one or more values of the mud and formation parameters can be identified by applying the one or more regression functions to the one or more tool measurements.

Abstract: The disclosed embodiments include systems and methods to image a borehole. In one embodiment, a borehole imaging system having a borehole imaging tool and a processor is provided. The borehole imaging tool includes a magnetic field source and an array of electrode buttons. The borehole imaging tool also includes a galvanic source operable to inject an electrical current through one or more electrode buttons of the array of electrode buttons into the formation. The processor is operable to determine a differential voltage between at least two electrode buttons of the array of the electrode buttons, and determine the current through the one or more electrode buttons. The processor is also operable to determine a magnetic susceptibility and a resistivity of the formation based on the differential voltage and the current, respectively, and construct a visual representation of the formation based on the resistivity and the magnetic susceptibility of the formation.

Abstract: Aspects of the subject technology relate to systems and methods for identifying a mud angle associated with an electromagnetic imager tool based on tool measurements made during operation of the electromagnetic imager tool. Tool measurements made by an electromagnetic imager tool operating to log a wellbore in a formation can be gathered. The tool measurements can be decomposed into two quantities along a plurality of candidate mud angles for the electromagnetic imager tool. As follows, a mud angle associated with the electromagnetic imager tool can be identified from the plurality of candidate mud angles based on an amount of correlation between the two quantities for each of the plurality of candidate mud angles.

Abstract: Various embodiments include apparatus and methods implemented to monitor detection of a flood front of a waterflood in a formation. Embodiments can include control of current in a set of three current electrodes to inject current into a formation around a pipe in a wellbore, where the three current electrodes include two of the electrodes to inject current and the third electrode to operatively provide a current return. Response of the formation to the current injections can be communicated by interrogating an optical fiber that extends along a longitudinal axis of the pipe. Determination of progression of the waterflood with respect to the wellbore can be provided from controlling the current and interrogating the optical fiber over time. Additional apparatus, systems, and methods are disclosed.