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 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.

In some embodiments, a method includes conveying a downhole tool in a tubing, positioned in a casing which forms an annulus between the casing and a wellbore formed in a subsurface formation, the downhole tool having a rotatable transmitter and a receiver array. The method includes performing the following until an acoustic transmission has been emitted for each of a number of defined azimuthal positions: rotating the rotatable transmitter to one of the number of defined azimuthal positions, emitting the acoustic transmission, and detecting, by the receiver array and without rotation of the downhole tool beyond a rotation threshold, an acoustic response of a number of acoustic responses that is derived from the acoustic transmission. The method further includes computationally rotating, by a processor and after detecting, data of each of the number of acoustic responses in a pre-determined direction to generate a computationally rotated multipole response.

In some embodiments, a method includes conveying a downhole tool in a tubing, positioned in a casing which forms an annulus between the casing and a wellbore formed in a subsurface formation, the downhole tool having a rotatable transmitter and a receiver array. The method includes performing the following until an acoustic transmission has been emitted for each of a number of defined azimuthal positions: rotating the rotatable transmitter to one of the number of defined azimuthal positions, emitting the acoustic transmission, and detecting, by the receiver array and without rotation of the downhole tool beyond a rotation threshold, an acoustic response of a number of acoustic responses that is derived from the acoustic transmission. The method further includes computationally rotating, by a processor and after detecting, data of each of the number of acoustic responses in a pre-determined direction to generate a computationally rotated multipole response.

Systems and methods are provided for determining a formation body wave slowness from an acoustic wave. Waveform data is determined by logging tool measuring the acoustic wave. Wave features are determined from the waveform data and a model is applied to the wave features to determine data-driven scale factors The data-driven scale factors can be used to determine a body wave slowness within a surrounding borehole environment and the body wave slowness can be used to determine formation characteristics of the borehole environment.

A method and downhole tool is provided that uses beamforming to localize acoustic energy at a desired zone-of-interest within a wellbore traversing a subterranean formation. The tool has an array of transmitter elements configured to emit guided mode acoustic signals at variable amplitude and variable time delay, which are individually controlled by an amplitude factor and time delay assigned to respective transmitter elements. A set of amplitude factors and time delays can be assigned to the transmitter elements of the transmitter array such that the transmitter elements produce a focused acoustic beam at the desired zone-of-interest by combination of guided mode acoustic signals transmitted by the transmitter elements.

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.

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.

A Transducer in a downhole environment with an increased amplitude of the transducer output at lower frequencies. A transducer may include a bender bar, wherein the bender bar may include a first piezoelectric layer disposed on one surface of the bender bar, a second piezoelectric layer disposed on the opposite surface of the bender bar, and a metallic substrate disposed between the first piezoelectric layer and the second piezoelectric layer. The transducer may further include a first fixed end is attached to the bender bar and connects the bender bar to a base, a second fixed end opposite the first fixed end that attaches the bender bar to the base, and a compartment disposed within the base.

A Transducer in a downhole environment with an increased amplitude of the transducer output at lower frequencies. A transducer may include a bender bar, wherein the bender bar may include a first piezoelectric layer disposed on one surface of the bender bar, a second piezoelectric layer disposed on the opposite surface of the bender bar, and a metallic substrate disposed between the first piezoelectric layer and the second piezoelectric layer. The transducer may further include a first fixed end is attached to the bender bar and connects the bender bar to a base, a second fixed end opposite the first fixed end that attaches the bender bar to the base, and a compartment disposed within the base.