Abstract: A pin point corer for collecting samples from a seabed of a sea, having a control unit to be positioned on a vessel or similar remote position, a top lift unit, which can be attached to a lifting and lowering unit of a vessel via an cable, such that it can be lifted and lowered relative to the seabed, a corer unit, releasable attached to the top lift unit by a fixation unit and arranged for being at least partly driven into layers of the seabed to collect the samples from there, e.g. when released from the top lift unit, wherein the top lift unit comprises a positioning unit bi-directionally communicating with the control unit for controlling the position of the corer unit. The invention also relates to a respective system and a method for collecting samples by use of such a pin point corer.

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: The present invention provides a five-component marine natural gas hydrate intelligent sensing node, comprising a titanium alloy compartment, an information acquisition unit, an integrated control chip, and a power module; the integrated control chip comprises an intelligent computing unit and a transmission unit; the intelligent computing unit is configured for acquiring quality monitoring indicators of marine natural gas hydrates by feature extraction and transmitting reduced represented features to a monitoring device on the sea surface via the transmission unit.

Abstract: A method for use in surveying a subsurface region beneath a body of water by detecting compressional, P, waves propagating through the body of water includes locating one or more sensor systems in the water at or close to the subsurface region, using the or each sensor system to detect P waves in the water, and translating all or a portion of the data representing the detected P waves to a higher level above the subsurface region. In the method, the effects of S waves, propagating in the subsurface and converted at the water/subsurface interface into P waves propagating in the water or along the seabed interface, in the translated data is reduced.

Abstract: A seabed object detection system is provided. The system can include a receiver array including streamers. The system can include a plurality of receivers coupled with the streamers. The system can include a receiver array cross-cable to couple with the first streamer and to couple with the second streamer. The receiver array cross-cable can be disposed at a first depth of a body of water. The system can include a first diverter and a second diverter coupled with the receiver array cross-cable. The system can include a source array including a first source and a second source. The source array can be coplanar to the receiver array. The system can include a source array cross-cable to couple with the first source and to couple with the second source, the source array cross-cable disposed at a second depth of the body of water.

Abstract: The invention discloses a method for exploring passive source seismic frequency resonance, which includes the following steps: Step 1: collecting, with a detector, a response signal of underground medium to form seismic time series data; Step 2, transforming the data collected in step 1 into frequency domain data, via Fourier transformation; Step 3, performing frequency domain superposition on the data at a same detection point processed through step 2, to form frequency domain amplitude superposition data; Step 4, converting, through a correction with a standard well parameter, frequency domain data processed through step 3 into depth data; Step 5, processing the data obtained in step 4 to obtain imaging data Image(d), where the imaging data Image(d) is apparent wave impedance ratio or apparent wave impedance changing as depth. The method can perform spatial and attribute imaging of the underground medium by using the seismic wave resonance principle.

Abstract: 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.

Abstract: The present invention provides a multi-mode dispersion energy imaging device and method for a four-component marine interface wave of an ocean bottom seismometer, belonging to the technical field of marine seismic exploration. The method includes the following steps: designing an marine interface wave artificial seismic observation system, designing a reasonable observation system according to the geological condition of the operation area to ensure the resolution of the imaging to perform the marine artificial source seismic operation carrying out the data preprocessing of the seafloor surface wave, and then carrying out the three-component seismometer Scholte wave and the acoustic guided wave dispersion energy imaging, and the one-component hydrophone acoustic guided wave dispersion energy imaging; superposing and normalizing the three-component Scholte wave dispersion energy spectrum and the one-component acoustic guided wave dispersion energy spectrum. The device is implemented based on the method above.

Abstract: Techniques are disclosed relating to deblending of sources in multi-source geophysical survey data, including marine or land-based data. Recorded data may be aligned to a primary source. A deblending procedure may be iteratively applied to produce a residual term and deblended estimates for the primary source and one or more secondary sources. Following an iteration of the deblending procedure, the resultant data may be sorted according to a domain that renders the one or more secondary sources incoherent with respect to the primary source. The domain used for sorting may be different from a domain used to sort during an immediately prior iteration. In embodiments, the deblending procedure may use coherency filtering, and the coherency filtering may be weighted according to a signal-to-noise metric generated from the data being deblended.

Abstract: Apparatus and techniques are disclosed relating to a two-axis sensing element. In various embodiments, a two-axis sensing element includes a mounting plate that includes a first pair of mounting slots oriented in a first direction and a second pair of mounting slots oriented in a second, different direction. Further, in various embodiments, the two-axis sensing element may include a first pair of bender elements and a second pair of bender elements. The first pair of bender elements may be mounted through the first pair of mounting slots such that the first pair of bender elements is oriented in the first direction and the second pair of bender elements may be mounted through the second pair of mounting slots such that the second pair of bender elements is oriented in the second, different direction. In various embodiments, the mounting plate may transect each of the bender elements into two cantilever portions.

Abstract: Techniques for processing of seismic data. A seismic data set is received, wherein the seismic data set comprises a first data subset associated with a first seismic source and a second data subset associated with a second seismic source. An input is received indicating that a distance between the first seismic source and the second seismic source is greater than or equal to a threshold value. The second data set is filtered from the seismic data set to remove the second data subset from seismic data set to generate a filtered seismic data set in response to receiving the input and a coherence volume is generated based on the filtered seismic data set.

Abstract: Computing device, computer instructions and method for processing energy at a free-surface reflection relating to an air-water interface. The method includes receiving input seismic data recorded with seismic sensors; receiving wave-height data that describes an actual shape of a top surface of a body of water; processing up-going energy at a receiver and down-going energy following a reflection at the sea-surface, using the input seismic data and a linear operator modified to take into account the wave-height data; and generating an image of the subsurface based on the up-going energy or the down-going energy or a combination of the input seismic data and one of the up-going or down-going energy.

Abstract: A system and method are disclosed for predicting, and optionally removing surface multiples from acquired seismic data that lacks surface consistency, such as seismic data acquired using an Ocean Bottom Cable (OBC) or Ocean Bottom Node (OBN) system where the sources are located at or near the water's surface and the receivers are located at or near the ocean's floor. By processing the acquired seismic data using seismic interferometry, source side and/or receiver side operators can be generated which satisfy the surface consistency requirement of techniques such as Surface Related Multiple Elimination (SRME) so that SRME or the like can be used to predict the surface multiples.

Abstract: A method for processing seismic data includes receiving, by a seismic data processing system, signals representing seismic data recorded at a remote location. In addition, the method includes receiving, by the seismic data processing system, identification of a sensor via which the signals were acquired. Further, the method includes retrieving, by the seismic data processing system, a sensor transfer function that corresponds to the sensor and relates the motion of the sensor to the signals. The method also includes generating, by the seismic data processing system, based on the sensor transfer function and a reference transfer function, an inverse filter that when applied to the signals changes parameters of the signals to correspond to the reference transfer function. Moreover, the method includes applying, by the seismic data processing system, the inverse filter to the signals to conform the parameters of the signals to the reference transfer function.

Abstract: A method for deghosting marine seismic streamer data includes receiving the marine seismic data recorded from a single streamer. A representation of an upgoing wavefield in the marine seismic data is defined. The representation of the upgoing wavefield includes a first wave component in a plane and a second wave component that is perpendicular to the plane. A linear system is built that models a wavefield using the representation. The wavefield includes the upgoing wavefield and a downgoing ghost wavefield. The upgoing wavefield is estimated, within the representation, by inverting the linear system.

Abstract: Providing real-time prediction and mitigation of seismically-induced effects comprises receiving measured seismic data; pre-processing to transform to a uniform format; inputting the preprocessed data into a predictive model; training the predictive model to learn hidden patterns in recorded seismic data, and extract underlying relations between the received measured seismic data and a predicted response at a location of interest at further time instance, as described by the equation: uIpred(t+?)=model(uI(t), uM1(t), uM2(t), . . .

Abstract: Processes and systems for deblending blended seismic data with attenuated source signatures and free-surface effects are described. The blended seismic data may have been recorded in a marine survey in which multiple sources are activated in the body of water above a subterranean formation. Receivers record overlapping pressure and vertical velocity wavefield responses from the subterranean formation as corresponding blended pressure wavefield and blended vertical velocity wavefield. Processes and systems compute an upgoing pressure wavefield and a downgoing vertical velocity wavefield based on the blended pressure wavefield and blended vertical velocity wavefield. Deblended primary pressure wavefields are computed based on the upgoing pressure and downgoing vertical velocity. The deblended primary pressure wavefields may be used to generate images of the subterranean formation that are substantially free of source signatures and free-surface effects.

Abstract: A seismic streamer includes an outer sheath that forms an interior region of the seismic streamer of which a portion is filled with a gel or liquid. The streamer also includes at least one stress member placed off-center in the interior region, and multiple sensors mounted proximate to a center of the interior region, where the sensors include a pressure sensor and a motion sensor. The streamer further includes multiple tilt sensors mounted along the interior region. A method of manufacturing a seismic streamer includes placing at least one stress member off-center along a first direction, mounting multiple spacers along the stress member, and affixing sensors to respective spacers, where the sensors include a pressure sensor and a motion sensor. The method further includes mounting tilt sensors along the first direction and affixing an outer sheath to the streamer that forms an interior region of the seismic streamer.

Abstract: A method according to one aspect for deghosting seismic data includes determining wave heights in an area wherein marine seismic data have been acquired by actuating a seismic energy source in a body of water and detecting seismic energy at each of a plurality of spaced apart seismic receivers deployed in the water. A reflectivity distribution function of the water surface is determined using the determined wave heights. A ghost function is determined from the reflectivity distribution function. The ghost function is applied to the marine seismic data to deghost the marine seismic data. In other embodiments, the reflectivity distribution function may be used to invert notional source signatures from near field seismic energy or modeling/attenuation free-surface multiples for both land and marine seismic data.

Abstract: The present disclosure relates to piezoelectric detection circuits, methods and display devices. A piezoelectric detection circuit is provided that may comprise: a piezoelectric device to convert a pressure into a direct current (DC) signal and to convert a sound wave into an alternating current (AC) signal; a comparison circuit configured to output the direct current signal to a signal processor in a case where the piezoelectric device outputs DC signal, and to output the alternating current signal to the mixer in a case where the piezoelectric device outputs AC signal; the mixer configured to perform a mixing process on the AC signal to generate a mixed signal; and the signal processor configured to process the mixed signal output from the mixer or the direct current signal output from the comparison circuit, to detect the pressure or the sound.

Abstract: Effects of time variability of water velocities in seismic surveys are addressed. Traveltime discontinuities in the input seismic data which are associated with the time-variable water velocities are determined. The input seismic data is transformed from a data space that contains the traveltime discontinuities into a model space which does not contain the traveltime discontinuities. Then the transformed seismic data is reverse transformed from the model space back into the data space.

Abstract: The present disclosure relates to Target-Enclosing Extended Image deconvolution. In a first aspect, the present disclosure provides methods to construct, from surface seismic reflection data, extended image gathers, i.e. time- and space-varying fields corresponding to virtual sources and receivers inside a subsurface volume, to retrieve both local reflection and local transmission responses corresponding to two datums at depth: an original observation datum and a second datum completely enclosing a chosen target subsurface volume away from the original observation datum (e.g., enclosing a target reservoir at depth). The methods of the present disclosure retrieve responses that are devoid of interference due to structures that may exist both above and below the target volume, i.e., the retrieved responses correspond only to the properties of the medium within or inside of the target volume.

Abstract: The presently disclosed seismic acquisition technique employs a receiver array and a processing methodology that are designed to attenuate the naturally occurring seismic background noise recorded along with the seismic data during the acquisition. The approach leverages the knowledge that naturally occurring seismic background noise moves with a slower phase velocity than the seismic signals used for imaging and inversion and, in some embodiments, may arrive from particular preferred directions. The disclosed technique comprises two steps: 1) determining from the naturally occurring seismic background noise in the preliminary seismic data a range of phase velocities and amplitudes that contain primarily noise and the degree to which that noise needs to be attenuated, and 2) designing an acquisition and processing method to attenuate that noise relative to the desired signal.

Abstract: Techniques are disclosed relating to the determination of a warping attribute related to a difference between an up-going pressure wavefield and a down-going pressure wavefield received from a seismic data acquisition system. The warping attribute is used to determine a pseudo up-going or down-going pressure wavefield. The pseudo pressure wavefield is used to generate a modified record of geophysical data, which is stored in a non-transitory memory medium as a geophysical data product.

Abstract: The present disclosure is related to methods, systems, and machine-readable media for interference attenuation of a residual portion of seismic data, such as may be recorded in a marine seismic survey. Recorded seismic data can be separated into a portion attributed to a source and a residual portion. Seismic interference attenuation can be performed on the residual portion.

Abstract: An automatic filtering method includes: a step of analyzing an input signal so as to obtain a frequency spectrum of the input signal; and a step of selecting, on the basis of the frequency spectrum, at least one filter from among a plurality of preset filters and filtering the input signal. The step of selecting includes determining, on the basis of the frequency spectrum of, a signal type in the input signal; selecting, on a basis of the signal type, a corresponding filter corresponding to the signal type; filtering the input signal with use of a first parameter of the corresponding filter and setting a second parameter for the corresponding filter on a basis of a result of the filtering; and filtering the input signal with use of the second parameter set for the corresponding filter. The method may ensure a filtering effect against noise.

Abstract: A method for estimating a time variant signal representing a seismic source obtains seismic data recorded by at least one receiver and generated by the seismic source, the recorded seismic data comprising direct arrivals and derives the time variant signal using an operator that relates the time variant signal to the acquired seismic data, the operator constrained such that the time variant signal is sparse in time.

Abstract: Wavefield reconstruction may include reconstructing a wavefield at a location away from a seismic receiver based on seismic data sampled from the seismic receiver, a vector of model coefficients comprising a scattering potential, and at least one of a mapping matrix comprising a dictionary of Green's functions and an operator defined by a combination of a number of functions.

Abstract: Methods for processing seismic data are described. The method includes: obtaining seismic data; solving a series of partial differential wave equations, wherein a first partial differential wave equation describes propagation of a seismic wave going from a first reflector to a second reflector, wherein a second partial differential wave equation describes propagation of a seismic wave going from a second reflector to a third reflector, and wherein a third partial differential wave equation describes propagation of a seismic wave going from a third reflector to a seismic receiver, wherein outputting predicted internal multiples for further imaging or attenuation.

Abstract: A technique includes receiving seismic data indicative of measurements acquired by seismic sensors. The measurements are associated with a measurement noise. The technique includes estimating at least one characteristic of the measurement noise and deghosting the seismic data based at least in part on the estimated characteristic(s) of the measurement noise.

Abstract: Denoising seismic data can include extracting a first plurality of overlapping patches corresponding to a respective seismic data window selected from a plurality of seismic data windows, reshaping the first plurality of overlapping patches into patch vectors, and determining sparse approximations of the patch vectors based on a dictionary and a sparse coefficient vector. Denoising seismic data can also include reshaping the sparse approximations into a respective second plurality of overlapping patches, and constructing a denoised version of at least one of the plurality of seismic data windows using the respective second plurality overlapping patches.

Abstract: A computer-implemented method for testing a modulation transfer function or spatial frequency response of an imaging system includes, on a computing device, generating a plurality of accumulation cells running along an accumulation line. A boundary delineation divides a first segment of a digital test image captured by the imaging system from a second segment, and the plurality of accumulation cells collectively comprise a one-dimensional accumulation array. For each of the accumulation cells, a projection ray is generated that extends through the accumulation cell and through the digital test image Each accumulation cell is loaded with an accumulated pixel value based on pixel values sampled from each of a plurality of sampling locations along the projection ray. The modulation transfer function or spatial frequency response of the imaging system is derived from the one-dimensional accumulation array.

Abstract: The current document is directed to computational systems and methods carried out by the computational systems for propagating a combined source-and-receiver wavefield from a first level to a next, second level with respect to depth, time, or another dimension. The methods and systems, to which the current document is directed, apply an efficient complex, combined-source-and-receiver-wavefield propagation operator to a complex combined-source-and-receiver wavefield in order to propagate the complex combined-source-and-receiver wavefield to the next level. Real source and receiver wavefields at the next, second level can then be extracted from the complex combined-source-and-receiver wavefield at the next level.

Abstract: A method for a marine seismic survey can include towing streamers that are spaced apart in a cross-line direction by a streamer separation (L) and towing seismic source elements that are spaced apart in the cross-line direction by a source separation based on an integer (k), an inverse of a quantity of the seismic source elements (1/S), and the streamer separation as represented by (k+1/S)L. The seismic source elements can be actuated and seismic signals can be detected at each of a plurality of receivers on the streamers.

Abstract: Wavefield separation methods and systems that adjust near-continuous pressure and particle motion wavefields based on distance moved along a vessel track by the sensors when the wavefields were measured are disclosed. Methods and systems correct for the motion of the receivers in towed streamer seismic data in order to obtain a wavefield with approximately stationary-receiver locations. Wavefield separation may then be applied to the wavefield with approximately stationary-receiver locations.

Abstract: Computing systems, methods, and computer-readable media for noise mitigation in seismic multimeasurement data are disclosed.

Abstract: In order to use near-field measurements to obtain signature of a signal penetrating seafloor in a shallow water surveyed area, the water-bottom reflections' effect is removed. The removal is performed by obtaining first a far-field initial estimate from stacked primary pulses in the near-field measurements, and then estimating water-bottom reflection portions for different depths using differences between the near-field measurements and the far-field initial estimate. The signature of the air-gun for each shot is then deblended from the near-field measurement for the shot using the one of the water-bottom reflection portions according to a water-bottom depth associated with the shot location.

Abstract: A seismic sensor system includes a seismic sensor suspended in an acoustic medium, which is disposed between first and second sensor housings. The acoustic medium can be selected to preferentially transmit pressure wave energy, based on the acoustic impedance of the surrounding water column or other seismic medium. The acoustic medium can also be selected to preferentially dissipate or otherwise reduce the transmitted shear wave energy. The second housing can similarly be configured to dissipate shear wave energy, while transmitting pressure wave energy in the form of acoustic waves that propagate through the acoustic medium to the seismic sensor.

Abstract: Calculating hypocenters of microseismic events. At least some of the example embodiments are methods including: detecting seismic waves from a microseismic event, the detecting by a sensor array disposed on a seafloor, the microseismic event originating in a formation below the sensor array, and the detecting creates received data; separating the received data into up-going data and down-going data, the down-going data indicative of detected seismic waves after a first reflection of the seismic waves at a sea surface; and calculating a hypocenter of the microseismic event using both the up-going data and the first down-going data.

Abstract: Embodiments of dynamic gain adjustments in seismic surveys are described. One method of acquiring a seismic survey includes determining an arrival time at a seismic receiver of a downgoing seismic wavefield associated with a seismic source based at least in part on an estimated position of the seismic source, an estimated position of the seismic receiver, or combinations thereof. The method also includes adjusting a gain of the seismic receiver based at least in part on the determined arrival time of the downgoing seismic wavefield in order to, for example, help prevent overdriving or clipping of the seismic receiver when the downgoing seismic wavefield arrives at or passes by the seismic receiver.

Abstract: Controller and method for adapting a frequency sweep for a vibro-acoustic source element that is configured to generate acoustic waves during a seismic survey. The method includes driving a seismic source element to generate a current frequency sweep; recording seismic data with plural seismic sensors in response to the current frequency sweep; selecting, during the seismic survey, a data subset of the seismic data, wherein the data subset has a size less than 10% of the seismic data; calculating with a processing device an attribute based on the data subset; and calculating a new frequency sweep based on the attribute.

Abstract: Methods and systems to remove source wavefield and source ghost effects from marine seismic data are described. The methods and systems may be used to substantially remove source wavefield and source ghost effects from marine seismic data collected in rough weather conditions.

Abstract: A method for removing ocean bottom and/or geology related contamination. The method includes receiving first measurements corresponding to first seismic sensors mounted on a first source array; receiving second measurements corresponding to second seismic sensors mounted away from the first source array; processing the second measurements to determine a contamination model related to the ocean bottom and geology; removing the contamination model from the first measurements to obtain cleaned data; and calculating a source signature of the first source array based on the cleaned data.

Abstract: Method for performing simultaneous encoded-source inversion of geophysical data to estimate parameters of a physical property model (41), especially adapted for surveys without fixed-receiver acquisition geometry, such as marine seismic surveys with moving source and receivers. The encoding functions (32) used on the sources to generate one or more simultaneous encoded-source gathers of data (35), as well as to simulate the same (34), are orthogonal or pseudo-orthogonal with respect to cross-correlation. In addition, receivers are also encoded, with the receiver encoding being designed to make a given receiver less sensitive to sources to which it was not listening during the survey (38). The encoding functions may be temporal bandpass filters differing one from another by central frequency, phase, or both. Efficiency of the method may be further improved by grouping several sources into a super-source, grouping the corresponding gathers into a super-gather, and then applying the above encoding strategy.

Abstract: A technique includes determining an image of a subsurface geologic region of interest, where the image represents at least in part ghost energy that is attributable to reflections caused by a reflecting interface. The technique includes deghosting the image, which includes processing data representing the image in a processor-based machine to determine at least one impulse response of a modeling and migration of at least one point scatterer for the region and use the impulse response(s) to attenuate the ghost energy.

Abstract: Methods and systems that remove particle-sensor noise from measured vertical-velocity wavefield are presented. A approximate vertical-velocity data is computed from pressure data and vertical-velocity data at receiver coordinates of a seismic data acquisition system. The pressure data is composed of a pressure signal component and pressure-sensor noise and the vertical-velocity data is composed of a vertical-velocity signal component and particle-motion-sensor noise. A filter that gives a minimum difference between the vertical-velocity data and the approximate vertical-velocity data at each receiver coordinate is computed. Vertical-velocity data composed of the vertical-velocity signal component and approximate particle-motion-sensor noise based on the pressure-sensor noise is convolved with the filter at each receiver coordinate.

Abstract: This disclosure is directed to systems and methods of wavefield separation based on matching operators that represents the relationship between co-located pressure and particle motions sensors. A pressure wavefield and a particle motion wavefield emitted from a subterranean formation are measured using co-located pressure and particle motion sensors located along one or more streamers of a seismic data acquisition system. A matching operator that relates pressure sensor and particle motion sensor responses for co-located pressure and particle motion sensors is computed based on depth of the co-located pressure and particle motion sensors and on the measured pressure and particle motion wavefields. The matching operator and the measured pressure and particle motion wavefields may then be used to compute up-going and down-going wavefields.

Abstract: Marine seismic sources for exploring formations under the seafloor using reflection seismology include ghost attenuators for reducing or eliminating ghost signals. Such a ghost attenuator is located in the water above an individual source element and 5 water surface and is configured to dissipate energy of up-going signals and/or to redirect the up-going signals.

Abstract: The present disclosure is related to methods, systems, and machine-readable media for interference attenuation of a residual portion of seismic data, such as may be recorded in a marine seismic survey. Recorded seismic data can be separated into a portion attributed to a source and a residual portion. Seismic interference attenuation can be performed on the residual portion.

Abstract: Apparatus, computer instructions and method for deghosting seismic data related to a subsurface of a body of water. The method includes inputting data recorded by detectors that are towed by a vessel, the data being associated with waves travelling from the subsurface to the detectors; applying a migration procedure to the data to determine a first image of the subsurface; applying a mirror migration procedure to the data to determine a second image of the subsurface; joint deconvoluting the first image and the second image for deghosting a reflectivity of the subsurface; and generating a final image of the subsurface based on the deghosted reflectivity of the joint deconvoluting step.