Abstract: Disclosed are acoustic logging systems and methods that involve correlating broadband acoustic signals acquired by a plurality of acoustic sensors at multiple depths within a wellbore to compute covariance matrices and their eigenvalues in the frequency domain for a plurality of frequency bins. In accordance with various embodiments, acoustic sources are detected and located based on the eigenvalues viewed as a function of depth and frequency.

Abstract: A broadband ultrasonic transducer device (UTD) is disclosed that utilizes a plurality of narrow-band piezo electric elements grouped into single-frequency sub-arrays to provide a relatively simple, highly-reliable deterrent unit (DU) capable of emitting ultrasonic energy over a wide coverage area and at a sound pressure level that meets or exceeds other DU approaches. In an embodiment, the broadband UTD includes a housing portion configured to couple to a plurality of piezo sub-array plates. Each piezo sub-array plate includes a plurality of pockets or cavities to receive respective narrow-band (e.g., 1-3 kHz) piezo electro transducer elements with characteristics, e.g., geometries and material composition, that cause each to emit ultrasonic energy at a particular resonant frequency. A controller of the UTD implements a control scheme to emit ultrasonic energy in a plurality of output modes including a white noise node and a single-frequency mode for deterrence applications.

Abstract: An extremely low frequency hydrophone includes a housing forming an interior space comprising a backchamber. The housing includes an opening to the interior space, and a side of the housing comprises a diaphragm plate. A backplate is disposed inside the housing adjacent the diaphragm plate, and an electronics unit including a preamplifier is disposed in the interior space. The hydrophone further includes dielectric liquid substantially filling the interior space. A passageway permits inert gas to be introduced into the dielectric liquid in the interior space of the housing.

Abstract: A method of free-field broadband calibration of hydrophone sensitivity based on pink noise, relating to the field of free-field underwater acoustic measurement, and is mainly used for broadband measurements of hydrophone sensitivity in free-field. The method of the present disclosure is to transmit a broadband pink noise signal by controlling the signal source, and to perform the synchronous processing and FFT to the transmitted current signal and the received voltage signal, such as interception and zero padding, and finally obtain the transfer function in the frequency domain; by analyzing the direct wave and the reflected wave in the water tank, the transfer function is averaged by a rectangular window to eliminate the influence of the reverberation of the reflected wave in the water tank, so as to obtain the broadband transfer function of the free-field between the transmitting transducer and the hydrophone.

Abstract: A seabed object detection system is provided. The system can include a source array. The source array can include a first source and a second source. The system can include a data processing system including one or more processors. The data processing system can determine a position of the first source and can identify a first firing time of the second source. The data processing system can initiate a first source shot of the first source at a known position and the second source at a known time. The data processing system can determine a target position and estimated position for the first source. The data processing system can determine a second position of the first source based on a difference between the target position and the estimated position. The data processing system can initiate a second source shot of the first source at a known position.

Abstract: A hydrophone fairing, including: an airfoil-shaped streamline structure having a first half-shell and a second half-shell; a roof plate; and a base plate. The roof plate and the base plate are disposed on two ends of the airfoil-shaped streamline structure, respectively. The first half-shell includes an inner wall provided with a first stiffener, a first support, a second support, a first division plate, and a second division plate which are successively disposed on the inner wall along the direction from the roof plate to the base plate. The altitudes of the first support and the second support are identical relative to the roof plate or the base plate. The roof plate includes a first end and a second end, and the first end includes a first hole to which a rope is attached.

Abstract: A method for determining the location of a leak within a tubular having tubular components by sending an acoustic signal from an acoustic tool, receiving reflective signals from the acoustic signal, correlating the reflective signals with known tubular components, identifying an unexpected reflective signal and determining the location of a leak by correlating the location of the unexpected reflective signal with the known tubular components.

Abstract: An outer tubular is imaged by a pad assembly disposed within an inner tubular inserted within the outer tubular. The pad assembly is in contact with the inner tubular, and includes an acoustic pressure source, a backing mounted to a side of the acoustic pressure source, and an intervening layer between the acoustic pressure source and inner tubular. Signals generated by the pad assembly propagate radially outward from the inner tubular and reflect from the outer tubular. The generated and reflected signals travel through a medium between the inner and outer tubulars. An estimate of the distance between the inner and outer tubulars is based on the time from generation of the signal to when the reflected signal is sensed.

Abstract: Embodiments may be directed to marine geophysical surveying and associated methods. At least one embodiment may be directed to incorporation of a lock mechanism in a sensor streamer that interlocks the outer jacket with one or more of the spacers to prevent relative rotation between the outer jacket. An embodiment may provide a sensor streamer that includes an outer jacket, a plurality of spacers, and a locking mechanism. The outer jacket may be elongated in an axial direction and comprise an outer jacket surface and an inner jacket surface. The plurality of spacers may be positioned in the outer jacket at spaced apart locations in the axial direction, wherein each of the plurality of spacers comprises a spacer body having an outer spacer surface. The locking mechanism may interlock the outer jacket with at least one of the plurality of spacers.

Abstract: A vessel system includes a hull configured to provide buoyancy, one or more seismic sources configured to generate seismic energy, and a deployment apparatus configured to deploy the seismic sources from the hull to a water body or water column. A control system can be configured to operate the deployment apparatus, in order to deploy the seismic sources.

Abstract: The present disclosure relates to a method of processing seismic signals comprising: receiving a set of seismic signals, applying a wavelet transformation to the set of signals and generating transformed signals across a plurality of scales. Then for each scale determining coherence information indicative of the transformed signals and generating a comparison matrix comparing the transformed signals, then outputting seismic attribute information based on combined coherence information.

Abstract: A tool and a method for determining material quality of a hydrocarbon wellbore cross section, having one or more tubular elements having filling materials in between, is described. A tool includes a body and moveable assemblies, having multiple arms configured to be in contact with an inner wall of a downhole tubular element, that that are configured to move between a retracted position where the multiple arms of the moveable assemblies are within a housing located in the body of the tool and an extended position where the multiple arms of the moveable assemblies are protruding from the housing and are in contact with the inner wall of the downhole tubular element. The moveable assemblies comprise both an acoustic broad band source array that operates in the frequency range of 0-100 kHz and an acoustic broad band receiver array having a radially spaced acoustic broad band receiver.

Abstract: Techniques for determining a drill bit location includes identifying a plurality of acoustic energy signals received at a plurality of sets of acoustic receivers from a passive acoustic energy source that is part of a wellbore drilling system; processing the plurality of acoustic energy signals; determining a location of a drill bit of the wellbore drilling system based on the processed plurality of acoustic signals; and updating a geo-steering path of the drill bit based on the determined location of the drill bit.

Abstract: A seismic survey system is provided. The system can include a source array including a first sub-source array and a second sub-source array. The system can include a streamer coupled with the first sub-source array and a streamer coupled with the second sub-source array. The system can include a receiver array including a plurality of receivers. The system can include a lateral cable coupled with at least one of a first diverter or a second diverter and at least one of the first sub-source array or the second sub-source array. The system can include a positioning cable coupled with the first diverter and a positioning cable coupled with the second diverter. The system can include a power cable. The system can include a seismic data acquisition unit array including a plurality of seismic data acquisition units disposed on a seabed.

Abstract: A sensor suspension system for use in an underwater environment comprises a sensor (e.g., vector sensor) and a framework comprising a plurality of support structures, and a plurality of compliant devices that suspend the sensor within an inner volume of the framework. The plurality of compliant devices facilitate a symmetrical sensing response of the sensor in three degrees of freedom when deployed in the underwater environment. The framework is moveable from a collapsed position to an expanded position. A plurality of sensor suspension systems can be tethered together into a sensor array by a deployment control system operable to release a buoyant device, tethered to the sensor suspension systems, that vertically positions the plurality of sensor suspension systems into the sensor array. The buoyant device can cause each framework to expand via pulling force through the tethers upon release of the buoyant device.

Abstract: A method for identifying a shape of a borehole may comprise disposing a downhole tool into the borehole, wherein the downhole tool comprises at least one transducer, transmitting a pressure pulse from the at least one transducer, wherein the pressure pulse is reflected as an echo, recording the echo with the at least one transducer, producing data points based at least in part on the echo, each data point including a radial distance value and an azimuthal value corresponding to the radial distance value, performing a pre-selection, fitting a geometric shape to a plurality of data points within the borehole, and sorting out at least one of the plurality of data points based at least in part on the shape. A system for identifying shape of a borehole may comprise at least one transducer and an information handling system.

Abstract: An ultrasonic transmitter apparatus is configured to transmit an ultrasonic signal that communicates a binary identifier. The apparatus includes an ultrasound transmission system and is configured to transmit an ultrasonic signal that communicates the binary identifier according to an encoding in which each bit position in the binary identifier is associated with a respective pair of frequencies and with respective first and second time positions in the ultrasonic signal. The value of the bit position in the binary identifier determines which frequency of the pair of frequencies is transmitted at the first respective time position in the ultrasonic signal, with the other frequency of the pair of frequencies being transmitted at the second respective time position in the ultrasonic signal.

Abstract: Marine surveys carried out with multiple source arrays comprising three or more sources are discussed. Each source of a multiple source array is an array of source elements, such as air guns. The sources of a multiple source array may be arranged in particular type of configuration that is effectively maintained while the survey vessel travels a sail line. The sources of the multiple source array are activated to acoustically illuminate a subterranean formation with acoustic signals. Two or more sources of a multiple source array may be activated to create blended seismic data. Methods to deblend, source deghost, and attenuate noise in the blended seismic data obtained by using a multiple source array are also discussed.

Abstract: The present disclosure provides a method and a device for imaging diffracted waves based on azimuth-dip angle gathers and a storage medium, which relates to the technical field of seismic exploration, comprising firstly acquiring seismic data and generating target azimuth-dip angle gathers based on the seismic data, wherein the target azimuth-dip angle gathers are a set of all azimuth-dip angle gathers in which the Fresnel zones have been muted, and each of the azimuth-dip angle gathers represents a dip-angle gather corresponding to each azimuth angle; then detecting diffracted waves based on the target azimuth-dip angle gathers, and determining the type of the diffracted waves; and finally, imaging the diffracted waves based on the type of the diffracted waves to obtain a diffracted wave imaging result.

Abstract: The present invention discloses a submarine seismic monitoring apparatus and system based on the submarine Internet of things.