An apparatus, method, and system for determining body wave slowness from guided borehole waves. The method includes selecting a target axial resolution based on the size of a receiver array, obtaining a plurality of waveform data sets corresponding to a target formation zone and each acquired at a different shot position, computing a slowness-frequency 2D dispersion semblance map for each waveform data set, stacking the slowness-frequency 2D dispersion semblance maps to generate a stacked 2D semblance map, and determining a body wave slowness from the extracted dispersion curve. The method may also include generating a self-adaptive weighting function based on a dispersion model and the extracted dispersion curve, fitting the weighted dispersion curve and the dispersion model to determine a body wave slowness that minimizes the misfit between the weighted dispersion curve and the dispersion model. The method can be applied to both frequency-domain and time-domain processing.

A model is used to generate corrections to mitigate ideal condition artifacts in acoustic property values of an annular material in a cased wellbore. A mathematical model that generates acoustic property values at ideal conditions introduces artifacts into the acoustic property values. Acoustic measurements of an annular material are used to generate features that represent wellbore conditions and are not accounted for in the mathematical model that generates acoustic property values. A model will generate corrections for acoustic property values of an annular material with the features to yield a more accurate acoustic property profile for the annular material of a cased hole.

A method includes receiving well log data for a plurality of wells. A flag is generated based at least partially on the well log data. The wells are sorted into groups based at least partially on the well log data, the flag, or both. A model is built for each of the wells based at least partially on the well log data, the flag, and the groups.

A detection system includes a drill bit where electro-acoustic transducers operate as a transmitter and/or receiver, are integrated; electronic circuits; a control unit associated with a data storage unit and is powered by an electrical supply system, the processing and control unit for generating driving signals sent to the electro-acoustic transducer acting as a transmitter by the analogue driving electronic circuits, for acquiring signals received from the transducer and for processing the received signals to determine discontinuity interfaces and/or anomalies in pore pressures in geological formations; wherein each of the electro-acoustic transducers is in contact with a pressurised fluid and includes: a tubular body with two end portions opposed to each other longitudinally, internally a first chamber with the first end portion and a second chamber on one side adjacent and in fluid communication with the first chamber and, on the other side ending with the second end portion.

Reducing casing wave effects on sonic logging data by positioning two or more receivers in a borehole in a subsurface formation; receiving, at two or more receivers in a borehole in a subsurface formation, a first signal associated with a first acoustic signal originating from a first transmitter position; receiving, at the two or more receivers, a second signal associated with a second acoustic signal originating from a second transmitter position; creating a dataset based on the first signal and the second signal; identifying casing wave signals in the dataset based at least in part on the second signal; calculating inverse-phase casing wave signals based at least in part on the casing wave signals and the second signal; and reducing effects of the casing wave signals on the dataset using the inverse-phase casing wave signals.

An acoustic logging system includes a first transducer in contact with or in close proximity to a sound barrier configured to emit a beam of acoustic energy according to a first mode of operation or a second mode of operation. The system also includes one or more second transducers in contact with or in close proximity to the sound barrier, positioned axially away from the first transducer, configured to receive acoustic energy from a wellbore environment responsive to the beam. The first mode of operation is a transmit-receive mode of operation where the beam is steerable to interact with one or more wellbore components at a first angle and the second mode of operation is a pulse echo mode of operation where the beam interacts with the one or more wellbore components at a second angle different from the first angle.

Methods and systems are disclosed for determining a material property transition within a wellbore. In some embodiments, a method includes determining a material transition profile for each of a plurality of test points within a linear measurement path including, for each test point, determining an acoustic response for a first location within the linear measurement path, and determining an acoustic response for a second location within the linear measurement path. The test point is between the first and second locations. The method further includes generating a material transition profile for the test point based, at least in part, on a difference between the acoustic response at the first location and the acoustic response at the second location.

Methods, systems, devices, and products for well logging. Methods include conveying a logging tool in the borehole on a carrier; obtaining a borehole image over at least one interval of borehole depth from well logging measurements with a downhole imaging instrument; obtaining acoustic information representative of acoustic reflections from a far-field region of the formation; obtaining quantitative borehole fluid information indicative of properties of a formation fluid in a near-field region of the borehole; generating a borehole connectivity fracture model of the formation in dependence upon the borehole image, the quantitative borehole fluid information, and the acoustic information. Methods may include identifying near-field fractures from the borehole image, and/or identifying far-field fractures from the acoustic information. Methods may include generating a fracture interpretation correlating the near-field fractures with the far-field fractures, and generating the borehole connectivity fracture model of the formation in dependence upon the fracture interpretation.

A method and system for locating a reflector in a formation. The method may comprise broadcasting a sonic waveform as a shear formation body wave or a compressional formation body wave into the formation, recording a reflected wave from a reflector with the one or more receivers as dipole data by the dipole receiver and quadrupole data by the quadrupole receiver, and processing the dipole data and the quadrupole data with an information handling system to determine a location of the reflector from the borehole sonic logging tool. The system may comprise a borehole sonic logging tool and an information handling system. The borehole sonic logging tool may comprise one or more transmitters configured to transmit a sonic waveform into a formation and one or more receivers configured to record a reflected wave as a dipole receiver for dipole data and a quadrupole receiver for quadrupole data.

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.