An innovative apparatus and computer implemented methods to obtain values for a set of scalars corresponding to each force and displacement, which may be obtained from acoustical signals captured by sensors of a drill bit while drilling, in a material of known mechanical properties, such as a cement from casing the well, such that the application and use of the scalars in relation to measurements of the mechanics while drilling, such as the acceleration of the bit and motion of the bit captured by sensors such as accelerometers, allow for absolute values of mechanical rock properties to be obtained in rock formations, being drilled through, with otherwise unknown mechanical properties prior to drilling.

Acoustic imaging tools and methods use refracted wave amplitudes to generate borehole images, thereby providing a method and tool that is highly sensitive to borehole discontinuities.

Systems and methods for detecting faults in the active damping of a logging tool are disclosed herein. A wellbore logging tool system comprises a processor, a memory, a wellbore logging tool comprising an acoustic transmitter, and a logging tool control module. The logging tool control module is operable to receive sensor signals from one or more sensors coupled to the wellbore logging tool after a damping control signal has been transmitted to the acoustic transmitter. The logging tool control module is also operable to determine one or more expected sensor signals, determine error values using the expected sensor signals and the sensor signals received from the one or more sensors, and compare the error values with one or more thresholds.

A system includes at least one processing unit and a bottomhole assembly (BHA) that includes or communicates with the at least one processing unit. The BHA includes at least one drilling component and at least one acoustic transducer to convert drilling noise into one or more electrical signals. The at least one processing unit analyzes the one or more electrical signals or related data to categorize different components of the drilling noise as rock contact noise and mechanical noise. The at least one processing unit derives a data log, a plan, or a control signal based on the categorized drilling noise components.

A system for looking ahead of a drill bit includes a plane wave generator (PWG) tool deployed downhole inside a wellbore for formation evaluation and generation of reflection data, a power source providing electric power to the PWG tool for the formation evaluation and the generation of the reflection data, a surface control system receiving the reflection data from the PWG tool and generating image data of a subsurface rock formation based on the received reflection data, and a wireline that electrically couples the PWG tool to the power source and communicatively couples the PWG tool to the surface control system. The PWG tool includes a beam forming network (BFN) architecture and a plurality of antenna elements mounted to a base of the PWG tool to transmit and receive electromagnetic signals.

A rock breaking seismic source and active source three-dimensional seismic combined detection system uses a tunnel boring machine for three-dimensional seismic combined detection by active seismic source and rock breaking seismic source methods. Long-distance advanced prediction and position recognition of a geological anomalous body are realized using the active source seismic method. Machine construction is adjusted and optimized according to the detection result; real-time short-distance accurate prediction of the body is realized using the cutter head rock breaking vibration having weak energy but containing a high proportion of transverse wave components as seismic sources and adopting an unconventional rock breaking seismic source seism recording and handling method. An area surrounding rock quality to be excavated is represented and assessed. A comprehensive judgment is made to the geological condition in front of the working face with the results of active source and rock breaking seismic source three-dimensional seismic advanced detection.

A portion of an anisotropy formation through which a wellbore is formed can be identified. An estimate of an elastic anisotropy parameter for the portion can be adjusted based on a first quality control analysis using the elastic anisotropy parameter for the portion. The first signal representing the elastic anisotropy parameter for the portion. The estimate of the elastic anisotropy parameter for the portion can be adjusted based on a second quality control analysis using estimates for the elastic anisotropy parameters for two or more portions of the anisotropy formation.

Apparatus, methods, and systems for determining acoustic velocity behind casing or tubing in a subterranean wellbore. A method may include obtaining a plurality of waveform data sets corresponding to a plurality of propagation path regimes and obtaining a total wavefield across the receiver array. The method may also include determining a Green's function representing each of the plurality of propagation path regimes and determining a noise wavefield by convolving the Green's functions and a known transmitted pressure signal corresponding to the plurality of waveform data sets. The method may also include generating a reduced-noise wavefield by subtracting the noise wavefield from the total wavefield and estimating the acoustic velocity of a formation behind the casing or tubing from the reduce-noise wavefield.

A method including selecting a forward model based on a modeled well structure and including a single modeled acoustic source located in a modeled wellbore and a plurality of modeled acoustic sensors located in a modeled source area, simulating an acoustic signal generated by the single modeled acoustic source and received by each modeled acoustic sensor, calculating phases of the simulated acoustic signals received at each modeled acoustic sensor, obtaining with a principle of reciprocity a plurality of modeled acoustic sources in the modeled source area and a single modeled acoustic sensor in the modeled wellbore, calculating phase delays of the simulated acoustic signals between each modeled acoustic source and the single modeled acoustic sensor, detecting acoustic signals generated by a flow of fluid using acoustic sensors in a wellbore, and processing the acoustic signals using the phase delays to generate a flow likelihood map.

A sensor system for use in a wellbore is provided that can include a piezoelectric transducer for transmitting an acoustic wave into a fluid medium positioned in the wellbore by repeatedly bending between two positions in response to an actuation signal. The piezoelectric transducer can include at least four piezoelectric layers stacked on top of one another. Each of the four piezoelectric layers can be coupled to an adjacent layer via a bonding material. Each of the four piezoelectric layers can include a piezoelectric material, a top electrode coupled to a top surface of the piezoelectric material, and a bottom electrode coupled to a bottom surface of the piezoelectric material. The sensor system can also include a hydrophone for detecting a reflection or a refraction of the acoustic wave off an object in the wellbore and transmitting an associated signal to a processing device.