Electromagnetic azimuthal tool drive and acquisition circuitry

Abstract

A method that may include disposing an electromagnetic (EM) logging tool in a wellbore. The EM logging tool may include one or more transmitters disposed on the EM logging tool and one or more receivers disposed on the EM logging tool. The method may further include 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 current that emanates from the one or more tubulars, measuring the eddy current in the one or more tubulars with the receiver on at least one channel to obtain a plurality of measurements, and forming an EM log from the plurality of measurements.

Description

ELECTROMAGNETIC AZIMUTHAL TOOL DRIVE AND ACQUISITION CIRCUITRYBACKGROUND

[0001] For oil and gas exploration and production, a network of wells, installations and other conduits may be established by connecting sections of metal pipe together. For example, a well installation may be completed, in part, by lowering multiple sections of metal pipe (e.g., a casing string) into a wellbore, and cementing the casing string in place. In some well installations, multiple casing strings are employed (e.g., a concentric multi-string arrangement) to allow for different operations related to well completion, production, or enhanced oil recovery (EOR) options.

[0002] Electromagnetic (EM) techniques are commonly used to monitor the condition of the pipes in oil / gas wellbore including various kinds of casing strings and tubing. One common EM technique utilizes eddy current (EC). In EC, when the transmitter coil emits the primary transient EM fields, eddy currents are induced in the casing. These eddy currents then produce secondary fields which are combined with the primary fields to induce voltages on the receiver coil. The acquired data may then be employed to perform evaluation of the multiple pipes.

[0003] Early detection of metal loss of well components, like production tubing or casing, is of great importance to oil and gas wells management. Currently, the remote field eddy current (RFEC) tools may detect anomalies on multiple nested tubulars. This type of tool, based on axial transmitters that generate omnidirectional magnetic fields sensed by axial receivers, has low vertical resolution, and it has no azimuthal discrimination. That means the estimated metal loss is an average value of annular section of the pipe within the tool vertical resolution range. Therefore, it may fail to detect tubular anomalies, such as cracks, pitting, holes, and any metal loss due to corrosion may result in expensive remedial actions and shut down of production wells. Additionally, identifying tubular azimuthal anomalies in outer pipes or anomalies found on out pipes behind inner anomalies may be difficult.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] These drawings illustrate certain aspects of some examples of the present disclosure and should not be used to limit or define the disclosure.

[0005] Figure 1 illustrates an example of an EM logging tool disposed in a wellbore;

[0006] Figure 2 illustrates an example of arbitrary defects within multiple pipes;

[0007] Figure 3 A illustrates an example of an EM logging tool traversing a wellbore;

[0008] Figure 3B illustrates another example of an EM logging tool traversing a wellbore;Atorney Docket No. 1560-198621[2024-INV-l 12502-W003]

[0009] Figure 3C illustrates another example of an EM logging tool traversing a wellbore;

[0010] Figure 3D illustrates another example of an EM logging tool traversing a wellbore;

[0011] Figure 3E illustrates another example of an EM logging tool traversing a wellbore;

[0012] Figure 4 illustrates four subsystems in the EM logging tool;

[0013] Figures 5-10 are circuit diagrams of an EM transmitter multiplexing and control circuitry in different operating modes;

[0014] Figure 11 is a graph for modulation of a transmission signal; and

[0015] Figure 12-15 are electrical protection circuit diagrams of an EM transmitter multiplexing and control circuitry in different operating modes.DETAILED DESCRIPTION

[0016] This disclosure may generally relate to pipe inspection in subterranean wells and, more particularly, to methods and systems for estimating metal loss in multiple nested pipes. Electromagnetic (EM) sensing may provide continuous in-situ measurements of parameters related to the integrity of pipes in cased boreholes. As a result, EM sensing may be used in cased borehole monitoring applications. EM logging tools may be configured for multiple concentric pipes (e.g., for one or more) with the first pipe diameter varying (e.g., from about two inches to about seven inches or more).

[0017] EM logging tools may measure voltage induced by eddy currents to determine metal loss, location of collars, and use magnetic cores with one or more coils to detect defects in multiple concentric pipes. The EM logging tools may use pulse eddy current (time-domain) and may employ multiple (long, short, and transversal) coils to evaluate multiple types of defects in multiple concentric pipes. It should be noted that the techniques utilized in time-domain may be utilized in frequency-domain measurements. In examples, EM logging tools may operate on a conveyance. Additionally, EM logging tools may include an independent power supply, data acquisition circuitry, computer board, power amplifier, communication interface board, and may store the acquired data on memory.

[0018] Monitoring the condition of the production and intermediate casing strings is crucial in oil and gas field operations. EM eddy current (EC) techniques have been successfully used in inspection of these components. EM EC techniques include two broad categories: frequencydomain EC techniques and time-domain EC techniques. In both techniques, one or more transmitters are excited with an excitation signal, and the signals from the pipes are received and recorded for interpretation. The magnitude of a received signal is typically inversely proportional to the amount of metal that is present in the inspection location. For example, less signal magnitudeAtorney Docket No. 1560-198621[2024-INV-l 12502-W003] is typically an indication of more metal, and more signal magnitude is an indication of less metal or more metal. This relationship may allow for measurements of metal loss, which typically is due to an anomaly related to the pipe such as corrosion or buckling. Metal gain may indicate the presence of a collar.

[0019] Figure 1 illustrates an operating environment for an EM logging tool 100 as disclosed herein in accordance with some embodiments. EM logging tool 100 may comprise a transmitter 102 and / or a receiver 104. In examples, transmitters 102 and receivers 104 may be coil antennas. Furthermore, transmitter 102 and receiver 104 may be separated by a space between about 0.1 inches (0.254 cm) to about 200 inches (508 cm). In examples, EM logging tool 100 may be an induction tool that may operate with continuous wave execution of at least one frequency. This may be performed with any number of transmitters 102 and / or any number of receivers 104, which may be disposed on EM logging tool 100. In additional examples, transmitter 102 may function and / or operate as a receiver 104 or vice versa. EM logging tool 100 may be operatively coupled to a conveyance 106 (e.g., wireline, slickline, coiled tubing, pipe, downhole tractor, and / or the like) which may provide mechanical suspension, as well as electrical connectivity, for EM logging tool 100. Conveyance 106 and EM logging tool 100 may extend within casing string 108 to a desired depth within the wellbore 110. Conveyance 106, which may include one or more electrical conductors, may exit wellhead 112, may pass around pulley 114, may engage odometer 116, and may be reeled onto winch 118, which may be employed to raise and lower the tool assembly in wellbore 110.

[0020] Signals recorded by EM logging tool 100 may be stored on memory and then processed by display and storage unit 120 after recovery of EM logging tool 100 from wellbore 110. Alternatively, signals recorded by EM logging tool 100 may be conducted to display and storage unit 120 by way of conveyance 106. Display and storage unit 120 may process the signals, and the information contained therein may be displayed for an operator to observe and stored for future processing and reference. It should be noted that an operator may include an individual, group of individuals, or organization, such as a service company. Alternatively, signals may be processed downhole prior to receipt by display and storage unit 120 or both downhole and at surface 122, for example, by display and storage unit 120. Display and storage unit 120 may also contain an apparatus for supplying control signals and power to EM logging tool 100 in casing string 108.

[0021] A typical casing string 108 may extend from wellhead 112 at or above ground level to a selected depth within a wellbore 110. Casing string 108 may comprise a plurality of joints 130 or segments of casing string 108, each joint 130 being connected to the adjacent segments by a collarAtorney Docket No. 1560-198621[2024-INV-l 12502-W003]132. There may be any number of layers in casing string 108. Such as, a first casing 134 and a second casing 136. It should be noted that there may be any number of casing layers.

[0022] Figure 1 also illustrates a typical pipe string 138, which may be positioned inside of casing string 108 extending part of the distance down wellbore 110. Pipe string 138 may be production tubing, tubing string, casing string, or other pipe disposed within casing string 108. Pipe string 138 may comprise concentric pipes. It should be noted that concentric pipes may be connected by collars 132. EM logging tool 100 may be dimensioned so that it may be lowered into the wellbore 110 through pipe string 138, thus avoiding the difficulty and expense associated with pulling pipe string 138 out of wellbore 110.

[0023] EM logging tool 100 may include a digital telemetry system which may further include one or more electrical circuits, not illustrated, to supply power to EM logging tool 100 and to transfer data between display and storage unit 120 and EM logging tool 100. A DC voltage may be provided to EM logging tool 100 by a power supply located above ground level, and data may be coupled to the DC power conductor by a baseband current pulse system. Alternatively, EM logging tool 100 may be powered by batteries located within EM logging tool 100 and data provided by EM logging tool 100 may be stored within EM logging tool 100, rather than transmitted to the surface to display and storage unit 120 during logging operations. The data may include signals and measurements related to corrosion detection.

[0024] During operations, transmitter 102 may broadcast electromagnetic fields into subterranean formation 142. It should be noted that broadcasting electromagnetic fields may also be referred to as transmitting electromagnetic fields. The electromagnetic fields transmitted from transmitter 102 may be referred to as a primary electromagnetic field. The primary electromagnetic fields may produce Eddy currents in casing string 108 and pipe string 138. These Eddy currents, in turn, produce secondary electromagnetic fields that may be sensed and / or measured by receivers 104. Characterization of casing string 108 and pipe string 138, including determination of pipe attributes, may be performed by measuring and processing primary and secondary electromagnetic fields. Pipe attributes may include, but are not limited to, pipe thickness, pipe conductivity, pipe ovality, and / or pipe permeability.

[0025] As illustrated, receivers 104 may be positioned on EM logging tool 100 at selected distances (e.g., axial spacing) away from transmitters 102. The axial spacing of receivers 104 from transmitters 102 may vary, for example, from about 0 inches (0 cm) to about 40 inches (101.6 cm) or more. It should be understood that the configuration of EM logging tool 100 shown in Figure 1 is merely illustrative and other configurations of EM logging tool 100 may be used with the presentAtorney Docket No. 1560-198621[2024-INV-l 12502-W003] techniques. A spacing of 0 inches (0 cm) may be achieved by collocating coils with different diameters. While Figure 1 shows only a single array of receivers 104, there may be multiple sensor arrays where the distance between transmitter 102 and receivers 104 in each of the sensor arrays may vary. In addition, EM logging tool 100 may include more than one transmitter 102 and more or less than six receivers 104. In addition, transmitter 102 may be a coil implemented for transmission of magnetic field while also measuring EM fields, in some instances. Where multiple transmitters 102 are used, their operation may be multiplexed or time multiplexed. For example, a single transmitter 102 may broadcast, for example, a multi -frequency signal or a broadband signal. While not shown, EM logging tool 100 may include a transmitter 102 and receiver 104 that are in the form of coils or solenoids coaxially, orthogonally, and / or radially positioned within a downhole tubular (e.g., casing string 108) and separated along the tool axis. Alternatively, EM logging tool 100 may include a transmitter 102 and receiver 104 that are in the form of coils or solenoids coaxially, orthogonally, and / or radially positioned within a downhole tubular (e.g., casing string 108) and collocated along the tool axis.

[0026] Broadcasting of EM fields by transmitter 102 and the sensing and / or measuring of secondary electromagnetic fields by receivers 104 may be controlled by display and storage unit 120, which may include an information handling system 144. As illustrated, the information handling system 144 may be a component of or be referred to as the display and storage unit 120, or vice-versa. Alternatively, the information handling system 144 may be a component of EM logging tool 100. An information handling system 144 may include any instrumentality or aggregate of instrumentalities operable to compute, estimate, classify, process, transmit, broadcast, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system 144 may be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price.

[0027] Information handling system 144 may include a processing unit 146 (e.g., microprocessor, central processing unit, etc. ) that may process EM log data by executing software or instructions obtained from a local non-transitory computer readable media 148 (e.g., optical disks, magnetic disks). The non-transitory computer readable media 148 may store software or instructions of the methods described herein. Non-transitory computer readable media 148 may include any instrumentality or aggregation of instrumentalities that may retain data and / or instructions for aAtorney Docket No. 1560-198621[2024-INV-l 12502-W003] period of time. Non-transitory computer readable media 148 may include, for example, storage media such as a direct access storage device (e.g., a hard disk drive or floppy disk drive), a sequential access storage device (e.g., a tape disk drive), compact disk, CD-ROM, DVD, RAM, ROM, electrically erasable programmable read-only memory (EEPROM), and / or flash memory; as well as communications media such wires, optical fibers, microwaves, radio waves, and other electromagnetic and / or optical carriers; and / or any combination of the foregoing. Information handling system 144 may also include input device(s) 150 (e g., keyboard, mouse, touchpad, etc.) and output device(s) 152 (e.g., monitor, printer, etc.). The input device(s) 150 and output device(s) 152 provide a user interface that enables an operator to interact with EM logging tool 100 and / or software executed by processing unit 146. For example, information handling system 144 may enable an operator to select analysis options, view collected log data, view analysis results, and / or perform other tasks.

[0028] EM logging tool 100 may use any suitable EM technique based on Eddy current (“EC”) for inspection of concentric pipes (e.g., casing string 108 and pipe string 138). EC techniques may be particularly suited for characterization of a multi-string arrangement in which concentric pipes are used. EC techniques may include, but are not limited to, frequency-domain EC techniques and time-domain EC techniques.

[0029] In frequency domain EC techniques, transmitter 102 of EM logging tool 100 may be fed by a continuous sinusoidal signal, producing primary magnetic fields that illuminate the concentric pipes (e.g., casing string 108 and pipe string 138). The primary electromagnetic fields produce Eddy currents in the concentric pipes. These Eddy currents, in turn, produce secondary electromagnetic fields that may be combined with the primary electromagnetic fields to induce voltages in the receivers 104. Characterization of the concentric pipes may be performed by measuring and processing these electromagnetic fields.

[0030] In time domain EC techniques, which may also be referred to as pulsed EC (“PEC”), transmitter 102 may be fed by a pulse. Transient primary electromagnetic fields may be produced due to the transition of the pulse from “off’ to “on” state or from “on” to “off’ state (more common). These transient electromagnetic fields produce EC in the concentric pipes (e.g., casing string 108 and pipe string 138). The EC, in turn, produces secondary electromagnetic fields that may be sensed and / or measured by receivers 104 placed at some distance on EM logging tool 100 from transmitter 102, as shown on Figure 1. Alternatively, the secondary electromagnetic fields may be sensed and / or measured by a co-located receiver (not shown) or with transmitter 102 itself.Atorney Docket No. 1560-198621[2024-INV-l 12502-W003]

[0031] It should be understood that while casing string 108 is illustrated as a single casing string, there may be multiple layers of concentric pipes disposed in the section of wellbore 110 with casing string 108. EM log data may be obtained in two or more sections of wellbore 110 with multiple layers of concentric pipes. For example, EM logging tool 100 may make a first measurement of pipe string 138 comprising any suitable number of joints 130 connected by collars 132. Measurements may be taken in the time-domain and / or frequency range. EM logging tool 100 may make a second measurement in a casing string 108 of first casing 134, wherein first casing 134 comprises any suitable number of pipes connected by collars 132. Measurements may be taken in the time-domain and / or frequency domain. These measurements may be repeated any number of times for first casing 134, for second casing 136, and / or any additional layers of casing string 108. In this disclosure, as discussed further below, methods may be utilized to determine the location of any number of collars 132 in casing string 108 and / or pipe string 138. Determining the location of collars 132 in the frequency domain and / or time domain may allow for accurate processing of recorded data in determining properties of casing string 108 and / or pipe string 138 such as corrosion. As mentioned above, measurements may be taken in the frequency domain and / or the time domain.

[0032] In frequency domain EC, the frequency of the excitation may be adjusted so that multiple reflections in the wall of the pipe (e.g., casing string 108 or pipe string 138) are insignificant, and the spacing between transmitters 102 and / or receiver 104 is large enough that the contribution to the mutual impedance from the dominant (but evanescent) waveguide mode is small compared to the contribution to the mutual impedance from the branch cut component. In examples, a remotefield eddy current (RFEC) effect may be observed. In an RFEC regime, the mutual impedance between the coil of transmitter 102 and coil of one of the receivers 104 may be sensitive to the thickness of the pipe wall. To be more specific, the phase of the impedance varies as:and the magnitude of the impedance shows the dependence:where co is the angular frequency of the excitation source, u is the magnetic permeability of the pipe, o is the electrical conductivity of the pipe, and t is the thickness of the pipe. By using the common definition of skin depth for the metals as:Atorney Docket No. 1560-198621[2024-INV-l 12502-W003]The phase of the impedance varies as: P = 2~S(4) and the magnitude of the impedance shows the dependence: exp [^] (5)

[0033] In RFEC, the estimated quantity may be the overall thickness of the metal. Thus, for multiple concentric pipes, the estimated parameter may be the overall or sum of the thickness of the pipes. The quasi-linear variation of the phase of mutual impedance with the overall metal thickness may be employed to perform fast estimation to estimate the overall thickness of multiple concentric pipes. For this purpose, for any given set of pipes dimensions, material properties, and tool configuration, such linear variation may be constructed quickly and may be used to estimate the overall thickness of concentric pipes. Information handling system 144 may enable an operator to select analysis options, view collected log data, view analysis results, and / or perform other tasks.

[0034] Monitoring the condition of pipe string 138 and casing string 108 may be performed on information handling system 144 in oil and gas field operations. Information handling system 144 may be utilized with Electromagnetic (EM) Eddy Current (EC) techniques to inspect pipe string 138 and casing string 108. EM EC techniques may include frequency-domain EC techniques and time-domain EC techniques. In time-domain and frequency-domain techniques, one or more transmitters 102 may be excited with an excitation signal which broadcast an electromagnetic field and receiver 104 may sense and / or measure the reflected excitation signal, a secondary electromagnetic field, for interpretation. The received signal is inversely proportional to the amount of metal that is around transmitter 102 and receiver 104. For example, less signal magnitude is typically an indication of more metal, and more signal magnitude is an indication of less metal. This relationship may be utilized to determine metal loss, which may be due to an abnormality related to the pipe such as corrosion or buckling.

[0035] Figure 2 shows EM logging tool 100 disposed in pipe string 138 which may be surrounded by a plurality of nested pipes (e.g., first casing 134 and second casing 136) and an illustration of anomalies 200 disposed within the plurality of nested pipes, in accordance with some embodiments. As EM logging tool 100 moves across pipe string 138 and casing string 108, one or more transmitters 102 may be excited, and a signal (mutual impedance between 102 transmitter and receiver 104) at one or more receivers 104, may be recorded.

[0036] Due to eddy current physics and electromagnetic attenuation, pipe string 138 and / or casing string 108 may generate an electrical signal that is in the opposite polarity to the incident signal and results in a reduction in the received signal. Typically, more metal volume translates to moreAtorney Docket No. 1560-198621[2024-INV-l 12502-W003] lost signal. As a result, by inspecting the signal gains, it is possible to identify zones with metal loss (such as corrosion). In order to distinguish signals that originate from anomalies at different pipes of a multiple nested pipe configuration, multiple transmitter-receiver spacing, and frequencies may be utilized. For example, short-spaced transmitters 102 and receivers 104 may be sensitive to first casing 134, while longer spaced transmitters 102 and receivers 104 may be sensitive to second casing 136 and / or deeper (3rd, 4th, etc.) pipes. By analyzing the signal levels at these different channels with inversion methods, it is possible to relate a certain received signal to a certain metal loss or gain at each pipe. In addition to loss of metal, other pipe properties such as magnetic permeability and conductivity may also be estimated by inversion methods. It should be noted that inversion methods may include model-based inversion which may include forward modeling. However, there may be factors that complicate interpretation of losses. For example, deep pipe signals may be significantly lower than other signals. Double dip indications appear for long spaced transmitters 102 and receivers 104. Spatial spread of long spaced transmitter-receiver signals for a collar 132 may be long (up to 6 feet (1.8 meters)). Due to these complications, methods may need to be used to accurately inspect pipe features.

[0037] Figures 3A-3E illustrate an electromagnetic inspection and detection of anomalies 200 (e.g., defects) or collars 132 (e.g., Referring to Figure 2), in accordance with some embodiments. As illustrated, EM logging tool 100 may be disposed in pipe string 138, by a conveyance, which may comprise any number of concentric pipes. As EM logging tool 100 traverses across pipe 300, one or more transmitters 102 may be excited, and a signal (receiver 104 induced voltage generated by eddy currents secondary magnetic field caused by transmitters 102 primary magnetic field) at one or more receivers 104, may be recorded. Due to eddy currents and electromagnetic attenuation, pipe 300 may generate an electrical signal that is in the opposite polarity to the incident signal and results in a reduction in a received signal. Thus, more metal volume translates to greater signal lost. As a result, by inspecting the signal gains, it may be possible to identify zones with metal loss (such as corrosion). Similarly, by inspecting the signal loss, it may be possible to identify metal gain such as due to presence of a casing collar 132 (e.g., Referring to Figure 1) where two pipes meet with a threaded connection. In order to distinguish signals from different pipes in a multiple concentric pipe configuration, multiple transmitter-receiver spacing, and frequencies may be used. For example, short-spaced transmitters 102 and receivers 104 may be sensitive to pipe string 138, while long spaced transmitters 102 and receivers 104 may be sensitive to deeper pipes (e.g., first casing 124, second casing 136, etc.). By analyzing the signal levels at these different channels through a process of inversion, it may be possible to relate a certain received signal set to a certainAtorney Docket No. 1560-198621[2024-INV-l 12502-W003] set of metal loss or gain at each pipe. In examples, there may be factors that complicate the interpretation and / or identification of collars 132 and / or anomalies 200 (e.g., defects).

[0038] For example, due to eddy current physics and electromagnetic attenuation, pipes disposed in pipe string 138 (e.g., referring to Figure 1 and Figure 2) may generate an electrical signal that may be in the opposite polarity to the incident signal and results in a reduction in the received signal. Generally, as metal volume increases the signal loss may increase. As a result, by inspecting the signal gains, it may be possible to identify zones with metal loss (such as corrosion). In order to distinguish signals that originate from anomalies 200 (e.g., defects) at different pipes of a multiple nested pipe configuration, multiple transmitter-receiver spacing, and frequencies may be used. For example, short-spaced transmitters 102 and receivers 104 may be sensitive to first pipe string 138 (e.g., referring to Figure 2), while long spaced transmitters 102 and receivers 104 may be sensitive to deeper (2nd, 3rd, etc.) pipes (e.g., first casing 134 and second casing 136).

[0039] Analyzing the signal levels at different channels with an inversion scheme, it may be possible to relate a certain received signal to a certain metal loss or gain at each pipe. In addition to loss of metal, other pipe properties such as magnetic permeability and electrical conductivity may also be estimated by inversion. There may be several factors that complicate interpretation of losses: (1) deep pipe signals may be significantly lower than other signals; (2) double dip indications appear for long spaced transmitters 102 and receivers 104; (3) spatial spread of long spaced transmitter-receiver signal for a collar 132 may be long (up to 6 feet); (4) to accurately estimate of individual pipe thickness, the material properties of the pipes (such as magnetic permeability and electrical conductivity) may need to be known with fair accuracy; (5) inversion may be a non-unique process, which means that multiple solutions to the same problem may be obtained and a solution which may be most physically reasonable may be chosen. Due to these complications, an advanced algorithm or workflow may be used to accurately inspect pipe features, for example when more than two pipes may be present in pipe string 138.

[0040] During logging operations as EM logging tool 100 traverses across pipe 300 (e.g., referring to Figures 3 A-3E), an EM log of the received signals may be produced and analyzed. The EM log may be calibrated prior to running inversion to account for the deviations between measurement and simulation (forward model). The deviations may arise from several factors, including the nonlinear behavior of the magnetic cores, magnetization of pipes, mandrel effect, and inaccurate well plans. Multiplicative coefficients and constant factors may be applied, either together or individually, to the measured EM log for this calibration. As discussed above, there may be any number of arrangements and spacing between transmitters 102 and / or receivers 104. Additionally, transmitters 102 and / or receivers 104 may be created and / or arranged to add deep azimuthalAtorney Docket No. 1560-198621[2024-INV-l 12502-W003] sensitivity. The circuitry used to power and / or operate EM logging tool 100 may allow for the control and operation of transmitters 102 and / or receiversl04.

[0041] Figure 4 illustrates four subsystems, an EM transmitter drive circuitry 400, an EM transmitter multiplexing and control circuitry 402, a signal conditioning and data acquisition circuitry 404, and an information handling system 144, that together, may be utilized with transmitters 102 and / or receivers 104 for taking measurements of pipe string 138 and / or pipes 300 to quantify the metal loss at pipe string 138 and / or pipes 300. Each subsystem described below may comprise a drive circuitry and its distinctive characteristics, the control circuitry and its distinctive characteristics, the data acquisition circuitry and its distinctive characteristics, the information handling system 144 and its distinctive characteristics. Generally, an EM transmitter drive circuitry is a power amplifier with current and voltage control modes designed to drive EM fields / waves when used along one or more EM transmitter elements. With the use of information handling system 144 (e.g., referring to Figure 1) signal conditioning and data acquisition circuitry, which may comprise signal preamplifiers, one or more amplifiers, analog filters, and digital filters, may be utilized to visualize EM measurements from measurement operations of EM logging tool 100. The information handling system 144 may filter and select different data visualizations and processing algorithms. As described herein, information handling system 144 may be configured to apply a different digital filters on a raw digitized data, demodulate a received signal, perform a down sampling or an interpolation on a raw digitized data, generate a log image of a well scanned with an electromagnetic azimuthal tool, and / or receive and one or more digital commands to change a data sampling rate and a compression rate.

[0042] EM transmitter drive circuitry 400 may comprise one or more power amplifiers 406 that may be used to drive one or more transmitter 102 with pulsed current signal (waveform) or pulsed voltage signal (waveform) in a wide range of frequencies, from 0.01 Hz up to 10 kHz. This may be performed by drive circuitry in a current drive mode or a voltage drive mode, using one or more waveform generators. During operations, the frequency change is implemented using information handling system 144 (e.g., referring to Figure 4). As noted above, information handling system 144 may be connected to / and / or in communication with EM transmitter drive circuitry 400. Thus, information handling system 144 may instruct for the generation of the power amplifier input signal and read back the output voltage and current. Thus, a small signal (originally digital, converted to analog domain with an DAC - digital to analog converter) generated by a computer board (which forms at least a part of information handling system 144) is amplified by EM transmitter drive circuitry 400. Therefore, any modification in frequency or signal waveform shape occurs in the main computer, originally in the digital domain. The time domain operation (pulseAtorney Docket No. 1560-198621[2024-INV-l 12502-W003] generation) may use waveform modification in the main computer board, however, some additional routing of the signal may be needed. The time domain power signal may use a different power amplifier than the one used for the frequency domain. In examples, EM transmitter drive circuitry 400 may be driven with a single frequency or a combination of frequencies, using different waveforms such as sinusoidal, square, and triangular. Further, EM transmitter drive circuitry 400 may also be driven by pulsed voltage signals (waveforms) and / or current voltage signals (waveforms).

[0043] EM transmitter multiplexing and control circuitry 402 is a signal flow controller that may connect EM transmitter drive circuitry 400 to transmitters 102, which may be transceivers as illustrated or any other transmitter 102 described above. Control circuitry 402 may achieve code division multiple access (CDMA) or BPSK modulation (e.g., signal flow, modulation depth, or timing) with information handling system 144 (e.g., referring to Figure 4). It is an additional piece of firmware that implements the power amplifier input signal (the input signal in 400) with this specific characteristic of being modulated. This may allow for the ability to drive multiple transmitters at the same time and independently recover the receiver information by decoding the measured receiver signal using the modulation key applied to each transmitter signal. This enables faster logging, as each transmitter 102 does not need to be driven one at a time. To inject energy 408 into pipe string 138 and / or pipes 300, EM transmitter multiplexing and control circuitry 402 connects transmitters 102 to EM transmitter drive circuitry 400. Subsequently, to allow EM logging tool 100 to read response signal 410 from pipe string 138 and / or pipes 300, EM transmitter multiplexing and control circuitry 402 connects the transceivers and / or receiver 104 to signal conditioning and data acquisition circuitry 404. The aforementioned commutations generate voltage spikes that may deteriorate or permanently damage the switches and drive circuits. Therefore, a protection circuit may also be disposed within EM logging tool 100.

[0044] During operations EM transmitter drive circuitry 400 has a single output 412 that may be delivered for all transmitters 102. Then, EM transmitter multiplexing and control circuitry 402 illustrated as circuit 500, as illustrated in Figure 5, may be expansible to accommodate the n elements in EM logging tool 100 (e.g., referring to Figure 4). Further EM transmitter drive circuitry 400 may be connected to PAINI and PAIN2 nodes (e.g. referring to Figure 12, below), transmitters 102 and / or receivers 104 (e.g. referring to Figure 4) may be connected to the ETX / ERXHX and ETX / ERXLXarrows 502, and signal conditioning and data acquisition circuitry 404 (e.g., referring to Figure 4) may be connected to the ASuxand ASLXarrows 504. Additionally, filtering and antialiasing techniques may be utilized in conjunction with data acquisition circuitry 404 for signal conditioning and noise reduction. For filtering and anti-aliasing techniques, acquisition circuitryAtorney Docket No. 1560-198621[2024-INV-l 12502-W003]404 may be configured to sample an EM receivers’ voltage or an EM receiver’s current waveform simultaneously or sequentially. The signal from EM transmitter drive circuitry 400 is multiplexed by a matrix of switches, which allows the signal to be delivered individually to each transmitter 102 and / or receiver 104, multiplexed in time, as illustrated in Figure 6, or distributed to all transmitters 102 simultaneously, as illustrated in Figure 7. In this operation mode, switches SMxx 700 and SSxx 702 are connected on position 1, and switches Si to Sn706 are commuted to activate the desired transmitter 102. A TVS 704 may be used as protection circuit to provide a path for the leakage current in transmitters 102, preventing voltage surges. Then, when a switch is turned off the EM leakage current flows through TVS 1504, as illustrated in Figure 8.

[0045] Additionally, in measurement operations, the signal from transmitter 102 may be modulated. For example, EM transmitter multiplexing and control circuitry 402 may be capable of modulating the transmission signal with an EM transmitter element, for instance, by employing binary phase shift keying (BPSK) modulation, code division multiple access (CDMA), digitally modulates the analog transmitted signal using any pseudorandom codes (such as Hadamard codes), one or more amplitudes, one or more offsets, or one or more frequencies. In this operational mode, referring to Figure 9, switches SMxx 700 may modulate the transmission signal. The SMHX and SMLX switches are both connected in position 1 (direct polarization) or both connected in position 2 (reverse polarization) and are commuted at same time. Consequently, it is possible to invert the current flow through transmitters 102 and / or receivers 104 and modulate the transmission signal with a phase shift of 180°, as shown in Figure 10, where the first branch is 180° shifted with respect to the others.

[0046] As mentioned above, transmitters 102 and / or receivers 104 may be transceivers. A transceiver is a device that may act as transmitter 102 and / or receiver 104. Thus, switching may occur to change operation of the transceiver from operating as either as transmitter 102 or receiver 104. When the transceivers elements are operating as transmitters 102, the transceiver may be connected to EM transmitter drive circuitry 400 (e.g., referring to Figure 4). In this case, the switches SSxx 702 are set to position 1 as illustrated in Figures 6, Figure 7, and Figure 9. When the transceivers elements are operating as receivers 104, the transceiver may be connected to signal conditioning and data acquisition circuitry 404. In this case, switches SSxx 702 are set to position 2, as shown in Figure 11.

[0047] When transmitters 102 are being powered by an electrical current waveform, the voltage on power amplifier output 412 (e.g., referring to Figure 4) may be significantly increased if all switches are closed. Therefore, a protection circuit (TVS 704) is added to prevent damage to the power amplifier and switches. Figure 12 shows the protection circuit (TVS 704) that is usedAtorney Docket No. 1560-198621[2024-INV-l 12502-W003] between EM transmitter drive circuitry 400 and an EM transmitter multiplexing and control circuitry 402. As all the switches used in the transmitter multiplexing and control circuitry require a power supply a first protection is an electromagnetic relay 1300 (RLi) that provides a close path for the power amplifier current in case of a power supply failure, as shown in Figure 13. When the power supply is working properly, RLi 1300 is switched to position 3 and then the power flow between power amplifier output and the EM bus is controlled by two complementary solid-state relays 1302, SERi and SER2. SER2 provides a return path to the current when all other switches are off, as illustrated in Figure 14, and SERi communicates power to the EM bus, as shown in Figure 15.

[0048] In order to avoid high dv / dt and di / dt, which may be problematic for time domain operation and also may damage power amplifiers and switches, the switching between operating modes must be smooth. For this reason, the SSRs used are thyristors and a zero-crossing detection circuit. The thyristor turns off the SSR when the current is zero and the zero-crossing detection turns on the SSR when the voltage is close to zero, ensuring noiseless operation. Finally, TVSs 704 may clamp any other voltage surge from switch commutation. These components and circuits in Figures 5-15 may allow for transmission of a signal from transmitter 102 that may energize pipe string 138 and / or pipes 300 (e.g., referring to Figure 12) to create an eddy current. That eddy current may create a second signal that may then be sensed by EM logging tool 100.

[0049] During operations, signal conditioning and data acquisition circuitry 404 may prepare the signal sensed by receivers 104. Its function is to select the interest frequency range and adjust the voltage levels to ensure compatibility with the acquisition circuitry. The data acquisition circuitry is capable of sampling the receiver waveforms simultaneously or sequentially with a discretization ranging from 12 to 24 bits, according to the operation mode. Furthermore, the number of analog- to-digital converter (ADC) channels may be reduced by multiplexing the n channels. The control of transmission and recording of sensed signals may be performed at least in part by information handling system 144. In examples, information handling system 144 may preprocess the data digitized from the acquisition circuitry as subsystem of the electronic system. Then send the data to a second information handling system 144, as discussed above.

[0050] The proposed system is designed to accommodate a flexible number of transmitters 102, receivers 104, and transceivers for EM logging tool 100. This flexibility enables different modes of operation (which transmitter 102 and which receiver 104 should be used at a time and at which order) either for time domain or frequency domain. Thus, the systems and methods may allow for well logs to be generated in real time. The well logs generated may show anomalies 200 (e.g., referring to Figure 2) that may be found and identify their location respective to a well plan.Atorney Docket No. 1560-198621[2024-INV-l 12502-W003]

[0051] Improvements over current technology may be found in the control, drive, and data acquisition circuitry used with the EM logging tool. Specifically, four sub systems are presented that are an electromagnetic transmitter drive circuitry, an electromagnetic transmitter multiplexing and control circuitry 402, a signal conditioning and data acquisition circuitry, and / or a data processing system. As disclosed above, methods and systems describe the EM transmitter drive circuitry as a power amplifier with current and voltage control modes designed to drive EM fields / waves when used along one or more EM transmitter elements. Further, signal conditioning and data acquisition circuitry is an electronic data acquisition circuitry with signal preamplifiers, analog and digital filters, which is connected to a computer or has an embedded computer. The data processing system (information handling system 144) is a computer / software unit used by the end user to visualize the data logged. The data processing system has the option to filter and select different data visualizations and processing algorithms. The combination of the listed subsystems enables full control over an EM logging tool with one or more transmitting elements and one or more receiving elements. Its use can be extended to operate with EM azimuthal tools wherein one or more of its elements is a transceiver. The described system enables an azimuthal EM tool to generate angular sector data for nested pipes by utilizing multiple operating modes. By combining information from these modes, the system produces highly accurate pipe images. As a result, localized metal losses can be distinguished from intact areas — an advancement over current technologies, which only provide images without azimuthal resolution for nested pipes.

[0052] The preceding description provides various examples of the systems and methods of use disclosed herein which may contain different method steps and alternative combinations of components.

[0053] Statement 1 : A system may comprise a transmitter, a drive circuitry, an EM transmitter multiplexing circuitry, a control circuitry, a protection circuitry, or a signal conditioning circuitry.

[0054] Statement 2: The system of statement 1, further comprising at least on power amplifier is configured to simultaneously drive, one or more EM transmitter elements with one or more amplitudes, one or more phases, one or more offsets, or one or more frequencies.

[0055] Statement 3: The system of any previous statements, further comprising at least one power amplifier is configured to drive the transmitter with a frequency voltage signal or with a composition of one or more voltage signals with one or more frequencies.

[0056] Statement 4: The system of any previous statements, further comprising at least one power amplifier is configured to drive the transmitter with a frequency current signal or with a composition of one or more current signals with one or more frequencies.Atorney Docket No. 1560-198621[2024-INV-l 12502-W003]

[0057] Statement 5: The system of any previous statements, further comprising at least one power amplifier is configured to drive the transmitter with a pulsed voltage signal or a pulsed current signal.

[0058] Statement 6: The system of any previous statements, further comprising at least one power amplifier is configured to drive the transmitter with a signal contained in a frequency range of 0.01 Hz up to 10 kHz.

[0059] Statement 7: The system of any previous statements, further comprising at least one waveform generator.

[0060] Statement 8: The system of any previous statements, wherein the control circuitry is configured to multiplex in time a transmitter signal from the transmitter.

[0061] Statement 9: The system of any previous statements, wherein the control circuitry is configured to modulate a transmitter signal using any code division multiple access (CDMA) and one or more pseudorandom codes.

[0062] Statement 10: The system of any previous statements, wherein the control circuitry is configured to connect a transceiver element to an acquisition circuitry or to the drive circuitry.

[0063] Statement 11 : The system of any previous statements, wherein the control circuitry is configured to operate the drive circuitry in a current drive mode or a voltage drive mode.

[0064] Statement 12: The system of any previous statements, further comprising an acquisition circuitry, wherein the acquisition circuitry comprises at least one analog-to-digital converters (ADC).

[0065] Statement 13: The system of any previous statements, further comprising an acquisition circuitry configured to condition one or more waveforms through one or more analog filters and one or more amplifiers.

[0066] Statement 14: The system of any previous statements, further comprising an acquisition circuitry configured to sample a voltage or a current of a waveform simultaneously or sequentially.

[0067] Statement 15: The system of any previous statements, further comprising an acquisition circuitry configured to sample a voltage or a current of a waveform by multiplexing an analog-to- digital converters (ADC’s) input with one or more channels.

[0068] Statement 16: The system of any previous statements, further comprising an acquisition circuitry configured to sample and digitize a voltage or a current of a waveform with a discretization ranging from 12 bits to 24 bits.

[0069] Statement 17: The system of any previous statements, further comprising an information handling system configured to apply one or more digital filters on a raw digitized data.Atorney Docket No. 1560-198621[2024-INV-l 12502-W003]

[0070] Statement 18: The system of any previous statements, further comprising an information handling system configured to demodulate a received signal.

[0071] Statement 19: The system of any previous statements, further comprising an information handling system configured to perform a down sampling or an interpolation on a raw digitized data.

[0072] Statement 20: The system of any previous statements, further comprising an information handling system configured to generate a log image of a well scanned with an electromagnetic azimuthal tool.

[0073] Statement 21 : The system of any previous statements, further comprising an information handling system configured to receive and one or more digital commands to change a data sampling rate and a compression rate.

[0074] It should be understood that, although individual examples may be discussed herein, the present disclosure covers all combinations of the disclosed examples, including, the different component combinations, method step combinations, and properties of the system. It should be understood that the compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of’ or “consist of’ the various components and steps. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the elements that it introduces.

[0075] For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower limit may be combined with any upper limit to recite a range not explicitly recited, as well as, ranges from any lower limit may be combined with any other lower limit to recite a range not explicitly recited, in the same way, ranges from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. Additionally, whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range are specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values even if not explicitly recited. Thus, every point or individual value may serve as its own lower or upper limit combined with any other point or individual value or any other lower or upper limit, to recite a range not explicitly recited.

[0076] Therefore, the present examples are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular examples disclosed above are illustrative only and may be modified and practiced in different but equivalent manners apparentAttorney Docket No. 1560-198621 [2024-INV-l 12502-W003] to those skilled in the art having the benefit of the teachings herein. Although individual examples are discussed, the disclosure covers all combinations of all of the examples. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. It is therefore evident that the particular illustrative examples disclosed above may be altered or modified and all such variations are considered within the scope and spirit of those examples. If there is any conflict in the usages of a word or term in this specification and one or more patent(s) or other documents that may be incorporated herein by reference, the definitions that are consistent with this specification should be adopted.

Claims

Atorney Docket No. 1560-198621[2024-INV-l 12502-W003]CLAIMSWhat is claimed is:

1. A system comprising: a transmitter; a drive circuitry; an EM transmitter multiplexing circuitry; a control circuitry; a protection circuitry; and a signal conditioning circuitry.

2. The system of claim 1, further comprising at least on power amplifier is configured to simultaneously drive, one or more EM transmitter elements with one or more amplitudes, one or more phases, one or more offsets, or one or more frequencies.

3. The system of claim 1, further comprising at least one power amplifier is configured to drive the transmitter with a frequency voltage signal or with a composition of one or more voltage signals with one or more frequencies.

4. The system of claim 1, further comprising at least one power amplifier is configured to drive the transmitter with a frequency current signal or with a composition of one or more current signals with one or more frequencies.

5. The system of claim 1, further comprising at least one power amplifier is configured to drive the transmitter with a pulsed voltage signal or a pulsed current signal.

6. The system of claim 1, further comprising at least one power amplifier is configured to drive the transmitter with a signal contained in a frequency range of 0.01 Hz up to 10 kHz.

7. The system of claim 1, further comprising at least one waveform generator.

8. The system of claim 1, wherein the control circuitry is configured to multiplex in time a transmitter signal from the transmitter.

9. The system of claim 1, wherein the control circuitry is configured to modulate a transmitter signal using any code division multiple access (CDMA) and one or more pseudorandom codes.

10. The system of claim 1, wherein the control circuitry is configured to connect a transceiver element to an acquisition circuitry or to the drive circuitry.

11. The system of claim 1, wherein the control circuitry is configured to operate the drive circuitry in a current drive mode or a voltage drive mode.

12. The system of claim 1, further comprising an acquisition circuitry, wherein the acquisition circuitry comprises at least one analog-to-digital converters (ADC).Atorney Docket No. 1560-198621 [2024-INV-l 12502-W003]13. The system of claim 1, further comprising an acquisition circuitry configured to condition one or more waveforms through one or more analog filters and one or more amplifiers.

14. The system of claim 1, further comprising an acquisition circuitry configured to sample a voltage or a current of a waveform simultaneously or sequentially.

15. The system of claim 1, further comprising an acquisition circuitry configured to sample a voltage or a current of a waveform by multiplexing an analog-to-digital converters (ADC’s) input with one or more channels.

16. The system of claim 1, further comprising an acquisition circuitry configured to sample and digitize a voltage or a current of a waveform with a discretization ranging from 12 bits to 24 bits.

17. The system of claim 1, further comprising an information handling system configured to apply one or more digital filters on a raw digitized data.

18. The system of claim 1, further comprising an information handling system configured to demodulate a received signal.

19. The system of claim 1, further comprising an information handling system configured to perform a down sampling or an interpolation on a raw digitized data.

20. The system of claim 1, further comprising an information handling system configured to generate a log image of a well scanned with an electromagnetic azimuthal tool.

21. The system of claim 1, further comprising an information handling system configured to receive and one or more digital commands to change a data sampling rate and a compression rate.

Images