Abstract: Methods and apparatus for automatic recognition of environmental parameters with azimuthally distributed transducers. For example, a toolstring is disposed in a cased portion of a borehole penetrating a subsurface formation. The toolstring comprises a module comprising azimuthally distributed acoustic transducers each operable to emit and receive acoustic signals. The module is operated to emit an acoustic signal into fluid surrounding the module in the casing and record data indicative of receipt, by a plurality of the transducers, of acoustic waveforms resulting from interaction of the emitted acoustic signal with the casing, including at least a non-specular diffraction head wave excited by a guided wave that is excited by diffraction of the acoustic signal propagating in the casing metal. Acoustic velocity of the guided wave in the casing metal is determined utilizing the recorded data and geometric parameters of the module.

Abstract: Methods including determining a measurement plan, having acoustic measurements, and lowering in a borehole penetrating a subsurface formation a toolstring having phased array modules. Each phased array module includes acoustic transducers operable to emit an acoustic excitation signal and receive an echo signal, as well as a programmable circuit for setting one or more variables of the phased array module. The phased array modules are configured, including programming the programmable circuit to set variables of the phased array modules according to the measurement plan. The acoustic measurements of the measurement plan are performed using the configured phased array modules. One or more of the formation, a casing disposed in the borehole, and/or an annulus between the casing and the formation are characterized using results of the performed acoustic measurements.

Abstract: A system and method for detecting defects in a tubular structure installed in a wellbore extending into a subterranean formation. An input image of the tubular structure contains input data indicative of a characteristic of the tubular structure. A background image is determined based on the input image. The background image contains background data indicative of the characteristic of the tubular structure associated with manufacturing of the tubular structure. A defect image is determined based on a difference between the input image and the background image. The defect image contains defect data indicative of the characteristic of the tubular structure associated with defects in the tubular structure.

Abstract: A system for wireline service planning and advising includes a receiver, one or more computing system processors, and a transmitter. The receiver is configured to receive, from a user of the system, an objective parameter for interpreting a state of a well barrier. The one or more computing system processors is in communication with the receiver and configured to generate a plurality of candidate services based on the objective parameter and a model of the well barrier, each candidate service specifying sensor data to be acquired using wireline tools, select at least one wireline service from the wireline candidate services based on a selection logic or input by the user, and generate an execution plan specifying operational parameters of the selected wireline service. The transmitter is in communication with the one or more computing system processors and configured to transmit the execution plan to execute the selected wireline service at a wellsite.

Abstract: Systems and methods for identifying a potential third interface echo (TIE) using objective criteria are provided. A system includes an acoustic logging tool that obtains measurements in a wellbore and a data processing system that has a processor that receives the measurements from the acoustic logging tool. The data processing system may identify a third interface echo (TIE) using a neural network and/or by a signal analysis method based on the behavioral characteristics of the TIE signal.

Abstract: Systems and methods for identifying a potential third interface echo (TIE) using objective criteria are provided. A system includes an acoustic logging tool that obtains measurements in a wellbore and a data processing system that has a processor that receives the measurements from the acoustic logging tool. The data processing system may identify a third interface echo (TIE) using a neural network and/or by a signal analysis method based on the behavioral characteristics of the TIE signal.

Abstract: Methods and apparatus for automatic recognition of environmental parameters with azimuthally distributed transducers. For example, a toolstring is disposed in a cased portion of a borehole penetrating a subsurface formation. The toolstring comprises a module comprising azimuthally distributed acoustic transducers each operable to emit and receive acoustic signals. The module is operated to emit an acoustic signal into fluid surrounding the module in the casing and record data indicative of receipt, by a plurality of the transducers, of acoustic waveforms resulting from interaction of the emitted acoustic signal with the casing, including at least a non-specular diffraction head wave excited by a guided wave that is excited by diffraction of the acoustic signal propagating in the casing metal. Acoustic velocity of the guided wave in the casing metal is determined utilizing the recorded data and geometric parameters of the module.

Abstract: Methods including determining a measurement plan, having acoustic measurements, and lowering in a borehole penetrating a subsurface formation a toolstring having phased array modules. Each phased array module includes acoustic transducers operable to emit an acoustic excitation signal and receive an echo signal, as well as a programmable circuit for setting one or more variables of the phased array module. The phased array modules are configured, including programming the programmable circuit to set variables of the phased array modules according to the measurement plan. The acoustic measurements of the measurement plan are performed using the configured phased array modules. One or more of the formation, a casing disposed in the borehole, and/or an annulus between the casing and the formation are characterized using results of the performed acoustic measurements.

Abstract: Acoustic imaging waveforms are measured utilizing a downhole acoustic tool within a wellbore, and then aligned relative to a main echo of each waveform. The aligned waveforms are then subjected to a first low-pass filter. Residuals are extracted by determining differences between the aligned waveforms and the filtered waveforms. The residuals are aligned to corresponding acoustic firing pulses of the downhole acoustic tool. The aligned residuals are subjected to a second low-pass filter. The measured waveforms are aligned to the corresponding acoustic firing pulses. Noise associated with the downhole acoustic tool is removed from the pulse-aligned, measured waveforms utilizing the filtered residuals.

Abstract: Acoustic imaging waveforms are measured utilizing a downhole acoustic tool within a wellbore, and then aligned relative to a main echo of each waveform. The aligned waveforms are then subjected to a first low-pass filter. Residuals are extracted by determining differences between the aligned waveforms and the filtered waveforms. The residuals are aligned to corresponding acoustic firing pulses of the downhole acoustic tool. The aligned residuals are subjected to a second low-pass filter. The measured waveforms are aligned to the corresponding acoustic firing pulses. Noise associated with the downhole acoustic tool is removed from the pulse-aligned, measured waveforms utilizing the filtered residuals.

Abstract: Acoustic imaging waveforms are measured utilizing a downhole acoustic tool within a wellbore, and then aligned relative to a main echo of each waveform. The aligned waveforms are then subjected to a first low-pass filter. Residuals are extracted by determining differences between the aligned waveforms and the filtered waveforms. The residuals are aligned to corresponding acoustic firing pulses of the downhole acoustic tool. The aligned residuals are subjected to a second low-pass filter. The measured waveforms are aligned to the corresponding acoustic firing pulses. Noise associated with the downhole acoustic tool is removed from the pulse-aligned, measured waveforms utilizing the filtered residuals.

Abstract: Acoustic imaging waveforms are measured utilizing a downhole acoustic tool within a wellbore, and then aligned relative to a main echo of each waveform. The aligned waveforms are then subjected to a first low-pass filter. Residuals are extracted by determining differences between the aligned waveforms and the filtered waveforms. The residuals are aligned to corresponding acoustic firing pulses of the downhole acoustic tool. The aligned residuals are subjected to a second low-pass filter. The measured waveforms are aligned to the corresponding acoustic firing pulses. Noise associated with the downhole acoustic tool is removed from the pulse-aligned, measured waveforms utilizing the filtered residuals.

Abstract: Techniques involve obtaining acoustic data (including waves reflected from the casing, the annular fill material, the formation, and/or interfaces between any of the mud, the casing, and the annular fill material) from an acoustic logging tool. Techniques include normalizing the acoustic wave to result in a normalized wave having a comparable spectral shape with a reference wave, and comparing the normalized wave with the reference wave. The reference wave may be generated or modeled or produced from a look-up table or database, and may be estimated based on initial estimates of wellbore parameters. Based on the comparison of the normalized wave with the reference wave, a best-fit reference wave substantially matching the normalized wave may be identified. The best-fit reference wave may correspond with a thickness of the casing, an acoustic impedance of the annular fill material, and an acoustic impedance of mud.

Abstract: A method of determining properties of a wellbore in a formation includes obtaining from the acoustic logging tool, acoustic data comprising an acoustic wave reflected from the casing, the annular fill material, one or more interfaces between any of the mud, the casing, and the annular fill material, or combinations thereof. The method includes normalizing the acoustic wave in a frequency domain, resulting in a specular spectrum and removing spectral noise outside a region of interest in the specular spectrum. The method includes shaping the specular spectrum around a resonance frequency, converting the shaped specular spectrum into a time domain, resulting in a renormalized waveform, and subtracting from the renormalized waveform one or more of a specular noise, second interface echoes, resulting in a third interface echo signal.

Abstract: Methods and systems for identifying and locating fractures within a wellbore are described herein. One such method includes generating an acoustic wave. At least a first portion of the acoustic wave travels along a wall of the wellbore. The first portion of the acoustic wave interacts with a feature on the wall of the wellbore, such as a fracture, and generates a second acoustic wave. The second acoustic wave is detected to obtain acoustic data. A chevron pattern is identified within the acoustic data and a location for the feature is determined using the identified chevron pattern.

Abstract: Methods and systems for identifying and locating fractures within a wellbore are described herein. One such method includes generating an acoustic wave. At least a first portion of the acoustic wave travels along a wall of the wellbore. The first portion of the acoustic wave interacts with a feature on the wall of the wellbore, such as a fracture, and generates a second acoustic wave. The second acoustic wave is detected to obtain acoustic data. A chevron pattern is identified within the acoustic data and a location for the feature is determined using the identified chevron pattern.

Abstract: A method of determining properties of a wellbore in a formation includes obtaining from the acoustic logging tool, acoustic data comprising an acoustic wave reflected from the casing, the annular fill material, one or more interfaces between any of the mud, the casing, and the annular fill material, or combinations thereof. The method includes normalizing the acoustic wave in a frequency domain, resulting in a specular spectrum and removing spectral noise outside a region of interest in the specular spectrum. The method includes shaping the specular spectrum around a resonance frequency, converting the shaped specular spectrum into a time domain, resulting in a renormalized waveform, and subtracting from the renormalized waveform one or more of a specular noise, second interface echoes, resulting in a third interface echo signal.

Abstract: Techniques involve obtaining acoustic data from an acoustic logging tool, where the acoustic data includes waves reflected from the casing, the annular fill material, the formation, and/or interfaces between any of the casing, the annular fill material, one or more interfaces between any of the mud, the casing, and the annular fill material. Techniques include normalizing the acoustic wave to result in a normalized wave having a comparable spectral shape with a reference wave, and comparing the normalized wave with the reference wave. The reference wave may be generated or modeled or produced from a look-up table or database, and may be estimated based on initial estimates of wellbore parameters. Based on the comparison of the normalized wave with the reference wave, a best-fit reference wave substantially matching the normalized wave may be identified.

Abstract: A transducer configured to be used in a downhole tool includes a radiating face to emit or receive an acoustic signal, a front electrode, a central layer behind the front electrode, and a back electrode behind the central layer, having a back face coupled to a backing material. The central layer has a substantially constant thickness throughout and includes a piezo-composite body and an insulating material. A configuration between the piezo-composite body and the insulating material variably reduces the central layer to reduce generation of side lobes.