Abstract: In at least one embodiment, a well inspection method and system enables transmission of an acoustic signal from a well inspection tool into a well structure and reception of return signals from the well structure at an array of receivers on the well inspection tool. The method and system enable performing of Short-Term Fourier Transform (STFT) on the return signals to generate spectrogram data that is used to determine short-term power spectra of the return signals. Time-dependent frequency response and location-dependent waveform propagation patterns are identified from the short-term power spectra. Cement bonding conditions is determined based on pattern matching using the time-dependent frequency response patterns and using the location-dependent waveform propagation patterns.

Abstract: The invention relates to a carrier (5) for transporting seismic nodes (9) to and from a sea floor (4), comprising an interior (8) for storing the nodes and a node transfer position (10) for transferring nodes (9) to and from the carrier (5); a support (14) for supporting the nodes (9) in a row (33) between the interior (8) of the carrier (5) and the node transfer position (10); and an endless driven belt or chain (11) with pushers (19) for pushing the row (33) of nodes (9). The invention also relates to a seismic node (9) adapted to use in the carrier (5). Further the invention relates to a method for loading seismic nodes (9) into the carrier (5), and a method for unloading seismic nodes (9) from the carrier (5).

Abstract: Downhole telemetry systems and related methods adaptively compensate for channel non-linearity effects. To compensate for channel non-linearity, the optimum signal generation parameters are determined that produce the desired modulated pressure variation at the surface. The signal generation parameters are optimized to minimize the discrepancy between the surface detected pressure signal and the intended signal. The mud propagation channel is first estimated in light of the known modulation scheme under an ideal linear-time-invariant channel assumption. The estimated channel is used to synthesize the modulated pressure signal undergoing the mud propagation given the initial signal generation parameters. The method then varies the synthesized signal generation parameters to search for the optimal signal generation parameters. The optimal signal generation parameters are then sent over downlink channel to the downhole pulser, which is ultimately used to generate the pulse waveform.

Abstract: Certain aspects and features relate to a system that includes a well tool configured to transmit an acoustic signal, detect a reflection signal, and transmit data representing the reflection signal. A processor analyzes the data to identify a pulse portion of the reflection signal, which is distinct from a reverberation portion. The processor determines a value for an attribute of the reflection signal, and executes a model to generate a first set of synthetic values for the attribute of the reflection signal and a second set of synthetic values for an impedance of a cement casing. The processor can then generate a lookup table that correlates the first set of synthetic values to the second set of synthetic values. By referencing the lookup table, processor can determine the impedance of the cement casing and alter a drilling plan or a completion plan based on the impedance of the cement casing.

Abstract: A method and systems for performing a borehole operation with a borehole fluid that includes applying an amplitude oscillation deformation force to a sample of the borehole fluid over a period of time, measuring the deformation force from the sample, determining a storage modulus of the borehole fluid over the period of time based on the measured deformation force, determining a gel strength of the borehole fluid by correlation with the storage modulus, comparing the gel strength with a desired gel strength and if the gel strength is outside of an acceptable range of the desired gel strength, adjusting a drilling parameter, a composition of the borehole fluid, or a combination thereof, and using the borehole fluid in the borehole operation. Determining the storage modulus and the gel strength may be done using a processor and the force may be applied using a piezoelectric device.

Abstract: Methods of mapping a subterranean formation using imploding particles are described. In some cases, the particles contain a material that generated a gas which passes through a water-insoluble coating to create a void within the particle. In some aspects, the implosive particles have a coating that dissolves in the subterranean formation.

Abstract: Techniques are described for utilizing far offset impulsive source activations in various contexts, including when performing marine seismic surveys, when manufacturing a geophysical data product in conjunction with such surveys, or when generating an image of geological features of a subsurface. According to some embodiments, near offset impulsive source activations are caused in a body of water at each of a plurality of near offset shot points, and composite far offset impulsive source activations are caused in the body of water at each of a plurality of far offset shot points. Each of the composite far offset impulsive source activations comprises a succession of component impulsive source activations occurring over a far offset shot length. The far offset shot length is short enough to satisfy a stationary source assumption for frequencies at or below a maximum frequency of interest for the far offset shot points.

Abstract: A method and system for generating an acoustic log. The method may comprise disposing an acoustic logging tool in a wellbore, broadcasting a shaped signal with the acoustic logging tool such that the shaped signal interacts with a boundary of a casing and a material, recording a result signal from the boundary with the acoustic logging tool, and decomposing the result signal into a resonance mode. The method may further comprise applying a bandpass filter to the resonance mode to form a filtered signal, selecting a baseline signal from the filtered signal, removing the baseline signal from the filtered signal, and generating a log from the filtered signal. The system may comprise an acoustic logging tool. The acoustic logging tool may comprise at least one transmitter and at least one receiver. The system may further comprise a conveyance and an information handling system communicatively connected to the acoustic logging tool.

Abstract: A method for evaluating a sealing material positioned between a casing of a wellbore and a subsurface formation in which the wellbore is formed includes emitting an acoustic waveform outward from a position within the casing and detecting a return waveform that is generated in response to the acoustic waveform interacting with a region of interest that includes at least a portion of the sealing material. The method includes determining a first time window of the return waveform associated with the region of interest and trimming the return waveform based on the first time window. The method further includes determining a first spectral power density for the first time window of the trimmed return waveform and determining a composition ratio for the region of interest based on the first spectral power density.

Abstract: Methods for performing a marine survey of a subterranean formation using a hybrid combination of ocean bottom seismic (“OBS”) receivers, wide towed sources, and moving streamers are described herein. In one aspect, a sail line separation in a crossline direction is determined based on an average streamer separation and number of streamers. An array of OBS receivers are deposited on a surface of a subterranean formation with an OBS receiver separation that is based on the sail line separation. Wide towed sources and streamers are towed above the array of OBS receivers behind a survey vessel that travels sail lines separated by the sail line separation. The wide towed sources may be activated above the array of OBS receivers. Wavefields reflected from the subterranean formation are recorded at the OBS receivers and receivers located in the streamers as seismic data.

Abstract: Systems and methods for retrieving seismic data acquisition units from an underwater seismic survey are provided. The system includes an underwater vehicle with a base and an underwater vehicle interlocking mechanism. The underwater vehicle receives environmental information and identifies a seismic data acquisition unit located on an ocean bottom. The underwater vehicle obtains an indication to perform a non-landing retrieval operation. The underwater vehicle sets a position of the underwater vehicle interlocking mechanism to extend away from the base of the underwater vehicle. The underwater vehicle retrieves the seismic data acquisition unit by coupling the underwater vehicle interlocking mechanism with a seismic data acquisition unit interlocking mechanism. The underwater vehicle stores the seismic data acquisition unit and then sets the underwater vehicle interlocking mechanism in a second position to perform the non-landing retrieval operation for a second seismic data acquisition unit.

Abstract: Embodiments relate to a system, to methods, and to a processing module for detecting one or more objects in the seabed, wherein the detection of the one or more objects is based on the scattering of the at least one acoustic signal at the one or more objects. The system comprises an attachment structure (10). The attachment structure is intended to mechanically couple a signal source (20) and a plurality of receivers (30) to a vessel or to a propulsion unit. The system comprises the signal source (20) configured to emit at least one acoustic signal towards the seabed. A wavelength of the acoustic signal is adapted to an expected size of the one or more objects. The system comprises the plurality of receivers (30). A distance between adjacent receivers is at most half the wavelength of the acoustic signal. The plurality of receivers is configured to generate a receiver signal based on a scattering of the at least one acoustic signal at the one or more objects.

Abstract: Methods and systems for detecting marine mammals. Acoustic data can be received from one or more hydrophones. The acoustic data can be sampled, and the sampled acoustic data can be transformed to time-frequency image data. The image data can be processed to transform the data for input to a model. The model can be trained to detect the presence or absence of marine mammal vocalizations in the acoustic data. The model can output a prediction of whether or not a mammal is present.

Abstract: The present invention concerns a system for marine seismographic data acquisition, in particular for use in survey design. The invention provides a method for marine seismographic acquisition whereby subsea data and information can be collected using sea floor receivers and suspended receivers simultaneously. This is achieved by aligning the geometries of the two acquisition techniques and utilizing a system of wide-towed seismic sources that produce seismic energy on all the source point locations required to fulfil both acquisition methods.

Abstract: An ultrasound imaging system includes a transducer array with a plurality of transducer elements configured to transmit an ultrasound signal, receive echo signals produced in response to the ultrasound signal interacting with structure, and generate electrical signals indicative of the echo signals. The system further includes a beamformer configured to process the electrical signals and generate radio frequency data, an in-phase quadrature processor configured to process the radio frequency data and generate in-phase quadrature data, and a frame processor configured to envelope detect and log compress the in-phase quadrature data, producing compressed envelope data. The system further includes a time gain compensation controller configured to continuously process the in-phase quadrature data and the compressed envelope data and continuously and automatically apply time gain compensation data to an envelope data image.

Abstract: Marine seismic surveys, including ocean bottom surveys, utilizing marine vibrator arrays that are capable of being driven in anti-phase to produce a directional source gradient. Marine seismic surveys may include activating the vibrator array to emit a plurality of radiation patterns with at least a first radiation pattern that has a first notch at a take-off angle that is not dose to vertical. Some marine seismic surveys included emitting directive wavefields from two or more simultaneous seismic source arrays, where the two or more seismic source arrays have a phase that changes from shot-to-shot to allow simultaneous source separation of the directive wavefields.

Abstract: A method for calculating a velocity vp(f, Topt) of a spatially aliased wave that propagates along a cable includes tensioning the cable, wherein plural sensors are distributed along the cable; measuring with the plural sensors a parameter that is associated with vibrations that propagate along the cable; calculating a phase velocity vp(f) of the spatially aliased wave that propagates along the cable, as a function of a time frequency fin a spatial-temporal frequency domain FK; calculating a model-based velocity vp(f, T) of the spatially aliased wave as a function of the time frequency f and a tension T in the cable; and calculating the velocity vp(f, Topt) of the spatially aliased wave using a model-guided regression, which is based on the phase velocity vp(f) and the model-based velocity vp(f, T). The velocity vp(f, Topt) is a function of the temporal frequency f.

Abstract: The invention relates to a method for seismic survey by autonomous seismic nodes (1) at a sea floor (2), comprising: —attaching the seismic nodes (1) to a rope (3); —loading the rope (3) with the seismic nodes into a node deployer (4); —lowering the node deployer (4) into the sea (5); —towing the node deployer (4) above the sea floor (2); —deploying the rope (3) with the seismic nodes (1) at the sea floor (2); —collecting seismic data by the seismic nodes (1); —retrieving the rope (3) with the seismic nodes (1) from the sea floor (2), and —unloading seismic data from the seismic nodes (1). The invention also relates to a node deployer (4) for deploying a rope (3) with seismic nodes (1) at the sea floor (2), comprising a magazine (7) for the rope (3) with the seismic nodes (1).

Abstract: Disclosed is a submersible buoy device and a control method thereof. The submersible buoy device includes an encapsulated housing, a watertight penetration socket, an underwater acoustic communication body, a data acquisition body, a control body and a mounting bracket. By integrally integrating the watertight penetration socket, the underwater acoustic communication body, the data acquisition body and the control body on the encapsulated housing, different types of multi-sensor data in the submersible buoy device can be automatically collected and processed. Adaptive scheduling and linkage control are carried out by the control body to the unity of each functional module, thereby achieving one-stop automatic operation of all measurement data to acoustic transmission communication.

Abstract: A surface wave prospecting method for jointly extracting Rayleigh wave frequency dispersion characteristics in a seismoelectric field. A surface wave prospecting method includes following steps of: acquiring jointly acquired data, where the jointly acquired data includes seismic wave data and electric field data; carrying out jointly imaging processing on jointly acquired data to obtain a superposed frequency dispersion spectrum; carrying out extraction processing on superposed frequency dispersion spectrum to obtain a frequency dispersion curve, outperforming inversion processing on frequency dispersion curve to obtain a stratum structure profile. As seismic wave data and electric field data are adopted to carry out combined imaging processing to obtain superposed frequency dispersion spectrum, multi-mode frequency dispersion curve is extracted, multiplicity of solutions of inversion is greatly reduced during inversion, precision and stability of surface wave prospecting are greatly improved.