A measurement device intended to be immersed in water, includes a set of arms and a reference axis, the measurement device being able to be in a deployed configuration, the measurement device comprising a set of measurement units borne by arms of the set of arms and each comprising an acoustic-waves sensor, the set of measurement units being configured and arranged in such a way as to generate a torque on the measurement device about the reference axis upon a vertical translational movement of the measurement device in the deployed configuration, the measurement device comprising compensation means configured and arranged in such a way as to generate another torque on the measurement device about the reference axis during the vertical translational movement, the other torque being directed in the opposite direction to the torque and having an intensity less than twice that of the torque.

A method for verticalizing recorded seismic data, the method including recording first data with a particle motion sensor, wherein the particle motion sensor is located on a streamer, and the particle motion sensor is configured to be insensitive to a direct current, recording second data with a gravity motion sensor, wherein the gravity motion sensor is also located on the stream, and the gravity motion sensor is configured to be sensitive to the direct current and temporally synchronous to the particle motion sensor, selecting a cost function that associates corresponding values of the first data and the second data, determining a misalignment angle from maximizing the cost function, wherein the misalignment angle describes a misalignment between corresponding axes of the particle motion sensor and the gravity motion sensor, and correcting seismic data recorded by the particle motion sensor based on the misalignment angle so that the corrected seismic data is verticalized with regard to gravity.

A plurality of sensors and a controller are disposed in a marine seismic streamer. Each of the sensors comprises an enclosure having two opposing interior walls, first and second piezoelectric elements disposed on the opposing interior walls, a third piezoelectric element disposed on a flexible substrate within the enclosure between the opposing interior walls, a pressure signal output node and an acceleration signal output node disposed on the exterior surface of the enclosure. A combined pressure signal derived from the pressure signal output nodes of the plural sensors is coupled to a pressure signal input of the controller. A combined acceleration signal derived from the acceleration signal output nodes of the plural sensors is coupled to an acceleration signal input of the controller. The streamer may be towed, and the combined pressure and acceleration signals may be recorded in a computer-readable medium.

An ocean bottom node for collecting seismic data, the ocean bottom node including a compounded housing including an electronics housing and a pinger housing, electronics located inside the electronics housing, and a battery pack configured to supply electrical power to the electronics. The pinger housing is permanently open to an ambient water while the electronics housing is sealed from the ambient water, and the pinger housing is configured to selectively and directly attach to the electronics housing.

An acoustic vector sensor (“AVS”) includes one or more sensitive elements arranged in an orthogonal configuration to provide high-sensitivity directional performance. The one more sensitive elements may be seismometers arranged in a pendulum-type configuration. The AVS further includes a hydrophone.

An inversion method for a multilayer seabed geoacoustic parameter in a shallow sea, includes: establishing a plurality of seabed models, different seabed models corresponding to different layer numbers, randomly generating a value of each geoacoustic parameter based on a preset change range corresponding to each geoacoustic parameter, then calculating to obtain a theoretical sound pressure value, and comparing the theoretical sound pressure value with an actual sound pressure value, adjusting and updating the value of each geoacoustic parameter according to the comparison result until the obtained theoretical sound pressure value is matched with the actual sound pressure value, and obtaining a target geoacoustic parameter value; calculating to obtain a BIC value corresponding to each seabed model; and taking the seabed model with the minimum BIC value as a target seabed model, and taking a target geoacoustic parameter value corresponding to the target seabed model as a target inversion parameter value.

A seismic attenuation quality factor Q is determined for seismic signals at intervals of subsurface formations between a seismic source at a marine level surface and one or more receivers of a well. Hydrophone and geophone data are obtained. A reference trace is generated from the hydrophone and geophone data. Vertical seismic profile (VSP) traces are received. First break picking of the VSP traces is performed. VSP data representing particle motion measured by a receiver of the well are generated. The reference trace is injected into the VSP data. A ratio of spectral amplitudes of a direct arrival event of the VSP data and the reference trace is determined. From the ratio, a quality factor Q is generated representing a time and depth compensated attenuation value of seismic signals between the seismic source at the marine level surface and the first receiver.

A hydrophone may include a first piezoelectric cable including alternating sections of positive polarity and negative polarity, and a second piezoelectric cable including alternating sections of negative polarity and positive polarity. At least a portion of each section of positive polarity of the first piezoelectric cable may be bonded or adhered to at least a portion of a section of negative polarity of the second piezoelectric cable. A method of manufacturing a hydrophone may include winding or coiling a first piezoelectric cable and a second piezoelectric cable at the same time to create a series of wound sections including cables, the wound sections alternating with a series of not wound sections including the cables.

A well tool can be used in a wellbore that can measure characteristics of an object in the wellbore. The well tool includes an ultrasonic transducer for generating an ultrasonic wave in a medium of the wellbore. The ultrasonic transducer includes a front layer, a rear layer, backing material coupled to the rear layer, and piezoelectric material coupled to the front layer and to the backing material. The rear layer can improve signal-to-noise ratio of the transducer in applications such as imaging and caliper applications.

A horizontal acoustic vector sensor system described herein includes a housing which has a gimbal assembly therein which is attached to a sensor assembly which has multiple pairs of seismometers that arranged orthogonally to one or more neighboring pairs of seismometers, along an approximately horizontal axis. The gimbal assembly with sensor assembly are enclosed within the housing by an endcap which includes an electronics assembly. The multiple pairs of seismometers are wired to the electronics assembly through a slip-ring which allows for movement of the gimbal assembly without entangling the wires. The horizontal acoustic vector sensor system further includes at least one omni-directional hydrophone integrated into the endcap.