Systems, devices, and methods for estimating a value of a parameter of interest of an earth formation intersected by a borehole. Methods include conveying a carrier in the borehole having disposed thereon an acoustic imaging tool including at least one convex linear phased array module, each of the at least one module comprising a rigid shell forming a compartment containing a piezoelectric component array; using the acoustic imaging tool to take acoustic measurements of the borehole; and using the acoustic measurements to estimate at least one parameter of interest. Each module may be self-contained. The tool may include a plurality of modules circumferentially arrayed about a portion of the acoustic tool. Methods include individually removing one selected module from the acoustic tool. Methods may include selecting an outer tool diameter the same as an inner borehole diameter borehole and selecting a maximum number of modules fitting the outer tool diameter.

Systems, devices, and methods for estimating a value of a parameter of interest of an earth formation intersected by a borehole. Methods include conveying a carrier in the borehole having disposed thereon an acoustic imaging tool including at least one convex linear phased array module, each of the at least one module comprising a rigid shell forming a compartment containing a piezoelectric component array; using the acoustic imaging tool to take acoustic measurements of the borehole; and using the acoustic measurements to estimate at least one parameter of interest. Each module may be self-contained. The tool may include a plurality of modules circumferentially arrayed about a portion of the acoustic tool. Methods include individually removing one selected module from the acoustic tool. Methods may include selecting an outer tool diameter the same as an inner borehole diameter borehole and selecting a maximum number of modules fitting the outer tool diameter.

Sensors for imaging boreholes via the detection of electrical and optical properties may be subject to harsh conditions downhole, such as from pressure and temperature. In addition, these sensors may be subject to impact, such as tension, elongation, and compression forces, along the wall of the borehole. The harsh conditions downhole and impacts on the sensor can lead to premature wear and even breaking. The present disclosure generally relates to an apparatus for measuring electrical and optical properties of the borehole and methods for manufacturing the apparatus.

In accordance with embodiments of the present disclosure, systems and methods for improving performance of ultrasonic transducers, particularly those used in borehole environments, are provided. The disclosed ultrasonic transducers all feature a backing element that is a ceramic backing material. The ceramic backing material may include a solid piece of ceramic material that is disposed on a back end of a piezoelectric element used in the ultrasonic transducer. The disclosed ceramic backing material may be used to mechanically match the backing element to the piezoelectric source element, while minimizing the amplitude of reflections of the ultrasonic pulse generated by the piezoelectric element and reflected at the far end of the backing element. This ceramic backing material may provide consistent performance regardless of the surrounding pressure and temperature, making it particularly useful in borehole applications.

In accordance with embodiments of the present disclosure, systems and methods for improving performance of ultrasonic transducers, particularly those used in borehole environments, are provided. The disclosed ultrasonic transducers all feature a backing element that is a ceramic backing material. The ceramic backing material may include a solid piece of ceramic material that is disposed on a back end of a piezoelectric element used in the ultrasonic transducer. The disclosed ceramic backing material may be used to mechanically match the backing element to the piezoelectric source element, while minimizing the amplitude of reflections of the ultrasonic pulse generated by the piezoelectric element and reflected at the far end of the backing element. This ceramic backing material may provide consistent performance regardless of the surrounding pressure and temperature, making it particularly useful in borehole applications.

A method comprising: conveying a downhole tool in a tubing that is positioned in a casing that is positioned to form an annulus between the casing and a wall of a wellbore formed in a subsurface formation, wherein a cement with unknown bonding condition exists in the annulus, wherein the downhole tool includes at least one transmitter and a receiver array physically positioned in different azimuthal directions; emitting, from the at least one transmitter, a first and second acoustic transmissions in a first and second azimuthal directions; detecting, by the receiver array, a first acoustic response and a second acoustic response that is derived from the first and second acoustic transmissions, wherein the second azimuthal direction is orthogonal to the first azimuthal direction; determining a dipole wellbore resonance based on the first and acoustic responses; and evaluating a property of the cement based on the dipole wellbore resonance.

Apparatus for acoustic measurement in a downhole environment to enable high quality measurements to be obtained in difficult logging conditions are disclosed. An example apparatus includes a downhole tool having a body with a plurality of transmitters located on the body. A receiver is located on the body a distance from the transmitters and an attenuator section is integrally formed on the body between at least one transmitter and the receiver.

Apparatus for acoustic measurement in a downhole environment to enable high quality measurements to be obtained in difficult logging conditions are disclosed. An example apparatus includes a downhole tool having a body with a plurality of transmitters located on the body. A receiver is located on the body a distance from the transmitters and an attenuator section is integrally formed on the body between at least one transmitter and the receiver.

Systems and methods for cement evaluation by determining a shear velocity of a shear wave (26) propagating within a medium (20) located between a formation (12) and a casing (13) in a borehole (11) are presented. The method can include positioning an ultrasonic transducer array (21) in the borehole inside the casing. The method can also include in a pushing mode, generating a shear wave in the medium with the ultrasonic transducer array inside the casing. The method can also include in an interrogation mode, measuring a shear velocity of the shear wave in the medium with the ultrasonic transducer array. The shear velocity may be used to determine whether the medium is solid or liquid.

Systems and methods for cement evaluation by determining a shear velocity of a shear wave (26) propagating within a medium (20) located between a formation (12) and a casing (13) in a borehole (11) are presented. The method can include positioning an ultrasonic transducer array (21) in the borehole inside the casing. The method can also include in a pushing mode, generating a shear wave in the medium with the ultrasonic transducer array inside the casing. The method can also include in an interrogation mode, measuring a shear velocity of the shear wave in the medium with the ultrasonic transducer array. The shear velocity may be used to determine whether the medium is solid or liquid.