Noise can be attenuated in marine seismic data from a marine seismic survey. A first near-continuous measurement of a wavefield and a second near-continuous measurement of the wavefield recorded from a marine seismic survey can be equalized, a coherent portion of the equalized second near-continuous measurement can be collapsed, and a noise model can be derived. The noise model can be subtracted from the second near-continuous measurement.

A dip angle-steering median filtering method based on a niche differential evolution algorithm, comprising the following steps: dividing a data to be processed into a series of overlapping time-space windows; obtaining an event energy curve in a time-space window and obtaining an event position according to a local maximum value of the event energy curve; obtaining event dip angles and coherence values of the event dip angles through the niche differential evolution algorithm at the event position; filtering the event dip angles according to the event dip angles and the coherence values of the event dip angles; and performing a median filtering sequentially along a filtering dip angle. The disclosure can simultaneously obtain all dip angles of intersecting events and a true three-dimensional feature enable the present disclosure to obtain a better filtering effect.

A system includes a first instrumented bridge plug positionable in a downhole wellbore environment. The first instrumented bridge plug includes an acoustic source for transmitting an acoustic signal. The system also includes a second instrumented bridge plug positionable in the downhole wellbore environment. The second instrumented bridge plug includes an acoustic sensor for receiving a reflected acoustic signal originating from the acoustic signal. The reflected acoustic signal being usable to interpret wellbore formation characteristics of the downhole wellbore environment.

Seismic data are obtained by recording simultaneously in seismic streamer, acquired by activating approximately simultaneously two or more seismic sources towed at two positions in the vicinity of seismic streamers. A residual is updated iteratively for an inversion solution for the activations of the two or more seismic sources. The iterative updating of the residuals utilizes a sequence of overlapping temporal windows containing reflection events and utilizes normal moveout corrections based on largest reflection events in each temporal window. A final updated residual is added to a final updated model result.

A non-blended dataset related to a same surveyed area as a blended dataset is used to deblend the blended dataset. The non-blended dataset may be used to calculate a model dataset emulating the blended dataset, or may be transformed in a model domain and used to derive sparseness weights, model domain masking, scaling or shaping functions used to deblend the blended dataset.

A method of identifying events includes obtaining an acoustic signal from a sensor, determining one or more frequency domain features from the acoustic signal, providing the one or more frequency domain features as inputs to a plurality of event detection models, and determining the presence of one or more events using the plurality of event detection models. The one or more frequency domain features are obtained across a frequency range of the acoustic signal, and at least two of the plurality of event detection models are different.

In the field of seismic data collection and analysis, the problem of data compression is considered. It is desired to reduce the storage and transmission requirements of seismic data, such as associated with microseismic monitoring and processing, VSP (vertical seismic profile) surveys, and the like, for instance using a distributed acoustic sensor (DAS), which can generate in excess of 50 GB of data per hour on a survey that lasts days. A method and system for data compression that separates the data collected into additive signal and noise components, and compresses the estimated signal component for transmission, storage, and analysis, is described. The idea is that the signal component, which exhibits clear structure across the traces, may be accurately described with relatively few parameters, and therefore may be significantly compressed without loss of important information.

A long-term in-situ observation device for the deep sea bottom supported engineering geological environment is provided, including: a sediment acoustic probe, a sediment pore water pressure probe, a three-dimensional resistivity probe, a water observation instrument, a long-term observation power supply system, a probe hydraulic penetration system, a general control and data storage transmission system, an acoustic releaser, an underwater acoustic communication apparatus, and an instrument platform. The observations include the engineering properties, physical properties, mechanical properties, and biochemical properties of a seawater-seabed interface-sediment. The engineering properties and the physical and mechanical indexes of seafloor sediments are comprehensively determined by three-dimensional measurement of seafloor resistivity and acoustic wave measurements. The physical and biochemical properties of seawater are expected to be acquired by sensors. The observation probe penetrates into the sediments following the hydraulic method.

A sonic tool is activated in a well having multiple casings and annuli surrounding the casing. Detected data is preprocessed using slowness time coherence (STC) processing to obtain STC data. The STC data is provided to a machine learning module which has been trained on labeled STC data. The machine learning module provides an answer product regarding the states of the borehole annuli which may be used to make decision regarding remedial action with respect to the borehole casings. The machine learning module may implement a convolutional neural network (CNN), a support vector machine (SVM), or an auto-encoder.

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.