Methods, systems, and program products are disclosed for implementing acoustic logging and determining wellbore material characteristics. In some embodiments, a method may include determining a polar differential signal for each of one or more pairs of azimuthally offset acoustic measurements within a wellbore. A reference azimuth is identified based, at least in part, on comparing the polar differential signals to a modeled bonding differential signal within a target response window. The method further includes determining differences between an acoustic measurement at the reference azimuth and acoustic measurements at one or more other azimuths and determining a wellbore material condition based, at least in part, on the determined differences.

Methods, systems, and program products are disclosed for implementing acoustic logging and determining wellbore material characteristics. In some embodiments, a method may include determining a polar differential signal for each of one or more pairs of azimuthally offset acoustic measurements within a wellbore. A reference azimuth is identified based, at least in part, on comparing the polar differential signals to a modeled bonding differential signal within a target response window. The method further includes determining differences between an acoustic measurement at the reference azimuth and acoustic measurements at one or more other azimuths and determining a wellbore material condition based, at least in part, on the determined differences.

The present disclosure discloses a method of obtaining a seismic while drilling signal. The method comprises the following steps: arranging geophones by using a first observation method to obtain a first seismic reference signal and a second seismic reference signal; arranging geophones by using a second observation method to obtain first seismic data; arranging geophones by using a third observation method to obtain second seismic data; comparing the first seismic reference signal with the second seismic reference signal to obtain a first output reference signal, and optimizing the first output signal to obtain a second output reference signal. The present disclosure obtains square matrix and near-wellhead seismic while drilling data through the combination of geophone square matrix combined observation, near-wellhead observation, and survey line observation, the data acquisition efficiency is relatively high, the signal-to-noise ratio is high, and thus, the problem of near-surface noise interference is effectively solved.

Downhole measurement systems and methods include deploying a bottomhole assembly having a multipole transmitter into a formation and transmitting acoustic signals into the formation. The multipole transmitter is of order n ≥ 2. Acoustic signals are received at respective receivers that are circumferentially aligned with the multipole transmitter, and are axially offset from the multipole transmitter, and axially offset from each other. The order of the first and second multipole receivers are equal to the order of the multipole transmitter. A controller is used to obtain first and second acoustic multipole data from the first and second multipole receivers at one or more azimuthal angles of a rotation of the bottomhole assembly in a formation during a drilling operation. Acoustic azimuthal anisotropy of the formation is determined from the first acoustic multipole data and the second acoustic multipole data.

Methods and systems for removing tool mode waveforms. The method may include disposing a bottom hole assembly (BHA) into a wellbore. The BHA may comprise at least one transmitter configured to transmit a pressure pulse and at least one receiver configured to record one or more waveforms. The method may further comprise performing a logging-while-drilling (LWD) operation in which the one or more waveforms are recorded with the at least one receiver, transmitting the one or more waveforms to an information handling system, removing one or more tool mode waveforms from the one or more waveforms to form an updated set of waveforms, and forming differential phase time semblance map based at least in part on the updated set of waveforms. The system may comprise the BHA and information handling system configured to remove one or more tool mode waveforms.

A system and methods for electrolysis of saline solutions are provided. An exemplary method provides simulating temperature gradients of reservoir fluids at different well conditions in a well, wherein the reservoir fluids include oil and water. A total flow rate of the reservoir fluids is quantified based on the simulated temperature gradients, and a water flow rate of water in the reservoir fluids is calculated based on, at least in part, a pulsed neutron log. An oil flow rate is calculated from the total flow rate of the reservoir fluids and the water flow rate.

A system and methods for electrolysis of saline solutions are provided. An exemplary method provides simulating temperature gradients of reservoir fluids at different well conditions in a well, wherein the reservoir fluids include oil and water. A total flow rate of the reservoir fluids is quantified based on the simulated temperature gradients, and a water flow rate of water in the reservoir fluids is calculated based on, at least in part, a pulsed neutron log. An oil flow rate is calculated from the total flow rate of the reservoir fluids and the water flow rate.

The disclosed embodiments include devices and methods to perform inversion processing of well log data. In one embodiment, a method to perform inversion processing of well log data includes obtaining an initial model of an earth formation based on a plurality of modeling parameters that includes formation parameters of the earth formation and calibration factors associated with orientations of antennas of a logging tool utilized to measure raw measurements of the earth formation. The method also includes performing a forward modeling of the modeling parameters to obtain a modeling response, and performing a joint cost function of the first modeling response and raw measurements obtained by the logging tool. The method further includes readjusting the initial model if a result of the joint cost function is not below a threshold, and providing the modeling response if the result of the joint cost function is below the threshold.

The disclosed embodiments include devices and methods to perform inversion processing of well log data. In one embodiment, a method to perform inversion processing of well log data includes obtaining an initial model of an earth formation based on a plurality of modeling parameters that includes formation parameters of the earth formation and calibration factors associated with orientations of antennas of a logging tool utilized to measure raw measurements of the earth formation. The method also includes performing a forward modeling of the modeling parameters to obtain a modeling response, and performing a joint cost function of the first modeling response and raw measurements obtained by the logging tool. The method further includes readjusting the initial model if a result of the joint cost function is not below a threshold, and providing the modeling response if the result of the joint cost function is below the threshold.

The subject technology relates to synthetic aperture to image leaks and sound sources. Other methods and systems are also disclosed. The subject technology includes drilling a wellbore penetrating a subterranean formation. The subject technology includes logging the wellbore using the stationary acoustic sensor and the moving acoustic sensor of the logging tool to obtain logged measurements, and obtaining an actual acoustic signal associated with a leak source in the wellbore using logged measurement data. The subject technology also includes determining a synthetic acoustic signal indicating an estimated leak source in the wellbore, and determining a correlation between the synthetic acoustic signal and the actual acoustic signal. The subject technology also includes generating a probability map from the determined correlation, in which the probability map indicates a likelihood of the leak source being located at a given location in the wellbore based on the probability map.