Abstract: A system, method, and sensor tool for enhancing sensor effectiveness. A wave is received utilizing multiple sensors in a downhole tool. Hodogram analysis of the wave is performed in response to measurements from the multiple sensors. A direction associated with the wave is determined. The multiple sensors are rotated to best sense the wave in response to the direction associated with the wave.

Abstract: Seismic pulses are emitted are emitted with consecutive time intervals that follow a pattern described by several Golomb rulers, wherein at least two of the Golomb rulers have at least four marks, such that pair-wise time intervals between seismic pulse emissions are different, to distinguish seismic reflections stemming from different seismic pulses and/or seismic sources from each other. This allows executing seismic surveys with several simultaneously operated seismic source arrays, thereby reducing the survey cost. In a marine environment the seismic sources may be air-gun arrays towed by one or more vessels, and the method can be also applied onshore.

Abstract: A method for seismic data acquisition can include near-continuously recording seismic data received from a number of seismic receivers and triggering a plurality of source elements, based upon time and not based upon position, at a predefined sequence of times relative to a start of a near-continuous recording.

Abstract: A method for seismic data processing can include obtaining seismic data acquired based upon trigger times and not based upon positions of triggered source elements. The seismic data can include near-continuously recorded seismic data in split records. The split records can be spliced together into a single near-continuous record to produce a trace with seismic data from a single acquired line. The seismic data can be processed by performing a spatial shift for each of a number of time samples to correct for motion of a number of seismic receivers.

Abstract: Methods, systems, and apparatuses are disclosed for sensing acoustic waves in a medium. One example system includes a first elongated member, a first motion sensor sensitive to vibrations of the first elongated member, a second motion sensor spaced apart from the first motion sensor and also sensitive to vibrations of the first elongated member, and a first vibration source operably coupled to the first elongated member and configured to vibrate the first elongated member.

Abstract: Determination of an impulse response at a subsurface image level can include extrapolation of an up-going pressure wavefield to a subsurface image level, extrapolation of a down-going velocity wavefield to the subsurface image level, and determination of the impulse response at the subsurface image level from a hypothetical seismic source by spectral division of the extrapolated up-going pressure wavefield by the extrapolated down-going velocity wavefield.

Abstract: A system and method of processing seismic data obtained using a plurality of towed single-component receivers in a marine environment is described, the towed single-component receivers configured to measure compressional P waves. The method comprises retrieving seismic data from a storage device, the seismic data comprising P-P data and shear mode data, wherein the P-P data and shear mode data were both received at the towed single-component receivers configured to measure compressional P waves to generate the seismic data. The method further comprises processing the seismic data to extract SV-P shear mode data and generating shear mode image data based on the extracted shear mode data.

Abstract: Provided is a method for swell effect and mis-tie correction in high-resolution marine seismic data using multi-beam echo sounder data, and more particularly, a method for swell effect and mis-tie correction in high-resolution marine seismic data using multi-beam echo sounder data capable of acquiring the high-resolution marine seismic data having the swell effect and the mis-tie effectively corrected by using the multi-beam echo sounder data including water depth data of a sea-bottom having high precision.

Abstract: Methods and systems for separating seismic data acquired using a plurality of substantially simultaneously fired sources are described. The sources use sweep sequences having low cross correlation levels to generate seismic waves, and their source signatures are determined. Using the source signatures, the wave fields associated with each of the sources are extracted from the seismic data by, for example, performing a time domain deconvolution.

Abstract: A sensor streamer stretch section. At least some of the example embodiments are methods including measuring at least one parameter related to noise while towing the sensor streamer through a body of water with a towing vessel, and adjusting at least one of a spring constant and a damping coefficient of a stretch section disposed proximate the sensor streamer such that the measured parameter is minimized.

Abstract: A marine streamer spread for acquiring seismic data, the spread including a streamer having a first portion and a second portion; the first portion including both first pressure sensors and pressure derivative sensors for acquiring the seismic data; and the second portion including second pressure sensors. The first portion imparts ghost diversity to the seismic data by having a variable-depth profile and the pressure derivative sensors impart polarity diversity to the seismic data.

Abstract: This disclosure is directed to wavefield separation methods and systems. In one aspect, methods and systems compute an approximate vertical particle velocity wavefield based on a measured pressure wavefield and knowledge of free-surface when the pressure wavefield was measured. The measured pressure wavefield is used to compute an approximate frozen free-surface profile. The approximate frozen free-surface profile and the measured pressure wavefield are used to compute an approximate vertical particle velocity wavefield. The approximate vertical particle velocity wavefield and measured pressure wavefield may be used to compute separate up-going and down-going pressure, or vertical particle velocity, wavefields.

Abstract: The present invention generally relates to marine seismic prospecting, and in particular to seismic prospecting using multiple vessels. During acquisition of seismic data, a distance between a first seismic vessel and a second seismic vessel may be adjusted according to a predefined function such that data is collected at a variety of offsets.

Abstract: The invention discloses a multi-beam bathymetric chart construction method based on submarine digital depth model feature extraction. The method comprises the steps of: constructing a DDM (Digital Depth Model) based on raw multi-beam echo soundings; establishing a slope and second derivative composite model based on the DDM; extracting feature points based on DDM sub-blocks; querying the multi-beam depth based on the feature points; constructing the multi-beam bathymetric chart based on layers.

Abstract: Methods and systems for synchronizing clocks used in underwater devices is described. All clocks have some drift due to frequency accuracy and this disclosure provides a method for periodically synchronizing clocks to an accurate master clock to remove long term drift. A synchronization device can use an accurate clock and hardware to transmit both a sound wave and light pulse at the same point in time. Remote slave clocks can detect the light first, and later the sound, allowing them to calculate the distance the pulse had to travel. The clocks can then synchronize their time to the master clock canceling out any drift. The synchronization device can be packaged in a waterproof housing and can be moved around on a periodic basis between the clock on an underwater robot or any other means.

Abstract: There is a method for finding a best distribution of source elements that form a vibratory source array. The method includes inputting plural constraints for the source elements; generating plural distributions of the source elements that fulfill the plural constraints; calculating for each distribution a performance index characterizing the source array; and selecting the best distribution from the plural distributions based on a value of the performance index.

Abstract: A method for uncertainty estimation for nonlinear inverse problems includes obtaining an inverse model of spatial distribution of a physical property of subsurface formations. A set of possible models of spatial distribution is obtained based on the measurements. A set of model parameters is obtained. The number of model parameters is reduced by covariance free compression transform. Upper and lower limits of a value of the physical property are mapped to orthogonal space. A model polytope including a geometric region of feasible models is defined. At least one of random and geometric sampling of the model polytope is performed in a reduced-dimensional space to generate an equi-feasible ensemble of models. The reduced-dimensional space includes an approximated hypercube. Probable model samples are evaluated based on data misfits from among an equi-feasible model ensemble determined by forward numerical simulation.

Abstract: A method for detecting hydrocarbons including obtaining seismic trace data for a region of interest; processing, using a processor, the seismic trace data to calculate a signal spectrum for each of a plurality of locations in the region of interest; calculating a dominant frequency of the signal spectrum; calculating at least one measure of energy decay above the dominant frequency, calculating at least one measure of energy decay below the dominant frequency, and calculating at least one measure spectral shape of the signal spectrum, and locating a hydrocarbon reservoir in the region of interest using the at least one measure of energy decay below the dominant frequency, the at least one measure of energy decay above dominant frequency and the dominant frequency; or locating a hydrocarbon reservoir in the region of interest using the at least one measure of energy decay below the dominant frequency and the at least one measure of energy decay above dominant frequency; or and locating a hydrocarbon reservoir

Abstract: Method and controller for finding a best distribution of source elements that form a vibratory source array. The method includes inputting plural constraints for the source elements; generating plural distributions of the source elements that fulfill the plural constraints; calculating for each distribution a first attribute characterizing the source array; and selecting the best distribution from the plural distributions based on a value of the first attribute.

Abstract: Operation of a marine vessel is disclosed. A marine vessel may be operated so as to determine that an end of a first sail line is approaching. Once determined, a turn path from the end of the first sail line to the beginning of a second sail line may be determined. The turn path may be determined based on at least one of current direction and current magnitude.

Abstract: Source signature of a source array is measured using an autonomous underwater vehicle which is not physically connected to surface equipment and uses acoustic signals for communication and/or location. Such measurements may be performed while the source array is towed, the AUV then moving in tandem with the source array.

Abstract: Embodiments of systems and methods for deploying and retrieving a plurality of autonomous seismic nodes from the back deck of a marine vessel using an overboard node deployment and retrieval system are presented. The overboard system may comprise one or more overboard wheels that are actively powered to move in response to changes in movement of the deployed cable. The overboard system may comprise a first overboard wheel with a plurality of rollers and a second overboard wheel configured to detect movement and/or changes in a position of the deployment line. The overboard system may be configured to move the first overboard wheel in response to movement of the second overboard wheel. In addition, the first overboard wheel may comprise at least one opening or pocket configured to hold a node while the node passes across the wheel. Other seismic devices may also pass through the overboard system, such as transponders and weights attached to the deployment cable.

Abstract: Method for estimating fluid heterogeneity in a subsurface region from seismic wave attenuation or velocity dispersion that is either measured or extracted from geophysical data (210). A rock physics model in the form of a mathematical relationship is selected that relates attenuation or velocity to frequency and to physical properties that are related to fluid heterogeneity (220). The model, or asymptotes (230) representing the model's behavior at frequency extremes, is inverted (240) and that relationship is used to obtain (250) one or more of the physical properties related to fluid heterogeneity, such as characteristic length scale for fluid saturation heterogeneities (270) and relative volume fractions of the fluids saturating the pore space (280).

Abstract: In voice processing, a first distribution generation unit approximates a distribution of feature information representative of voice of a first speaker per a unit interval thereof as a mixed probability distribution which is a mixture of a plurality of first probability distributions corresponding to a plurality of different phones. A second distribution generation unit also approximates a distribution of feature information representative of voice of a second speaker as a mixed probability distribution which is a mixture of a plurality of second probability distributions. A function generation unit generates, for each phone, a conversion function for converting the feature information of voice of the first speaker to that of the second speaker based on respective statistics of the first and second probability distributions that correspond to the phone.

Abstract: Systems and methods for detecting swell noise in geophysical data are disclosed. In particular, the systems and methods receive seismic data as input and iteratively generate a signal mask from the seismic data. The seismic data can be generated by hydrophones or geophones. The signal mask can be used to identify traces in the seismic data that are contaminated with swell noise and identify frequencies of the contaminated traces that are contaminated with swell noise.

Abstract: Computational systems and methods to be carried out by the computational systems for determining streamer-depth bias during exploration-seismology experiments are disclosed. An exploration-seismology vessel tows a number of streamers that form a smoothly varying data acquisition surface located beneath a fluid surface. In one aspect of this disclosure, the method determines a set of image points that represent a profile of the fluid surface above each streamer. The image points are determined based on pressure and velocity wavefields measured at dual sensors of the streamer. The method then determines an elevation parameter of the image points that minimizes DC offset in a spectral domain of the image points. The elevation parameter corresponds to the streamer-depth bias and can be used to correct for the streamer-depth bias in subsequent calculations of a fluid-surface profile.

Abstract: A technique includes receiving sensor acquired data, which includes pressure data representative of at least one pressure measurement of a wavefield and particle motion data representative of at least one particle motion measurement of the wavefield. The technique includes filtering the pressure data and the particle motion data with a plurality of directional filters to provide a plurality of filtered datasets. The filtered datasets are associated with different directional ranges. The technique includes estimating an angle of incidence for at least one of the directional ranges based at least in part on at least one of the filtered datasets; and processing the acquired data to determine at least one of an upgoing component of the wavefield and a downgoing component of the wavefield based at least in part on the at least one estimated angle of incidence.

Abstract: A method for generating a seismic image, comprising the steps of providing an input trace corresponding to seismic signals received at a receiver at a known receiver depth, using the input trace to generate a series of angle traces, each having a known time dip, for each angle trace, determining a filter H, for each angle trace, correcting the data by using the inverse of the filter H to generate a plurality of deghosted angle traces, copying each deghosted angle trace to a plurality of output locations and applying in each case the time dip for that angle trace so as to generate a plurality of corrected angle traces, at each output location summing a plurality of the corrected angle traces at that output location so as to generate a replacement trace; and using the replacement trace, preferably in combination with other replacement traces, to generate a seismic image.

Abstract: A system, method and computer-readable medium for developing an earth formation is disclosed. A tool conveyed in a borehole induces a stress in the earth formation proximate a borehole. A sensor assembly obtains a measurement of a physical property of the borehole at a plurality of azimuthal locations in the borehole. The values of the physical property are indicative of the induced stress in the formation. A processor forms an image of the borehole using the obtained measurements of the physical property, estimates an azimuthal variation with borehole depth of the induced stress in the formation from the formed image, and alters an operational parameter of a device for developing the earth formation using the estimated azimuthal variation with depth of the induced stress in the formation.

Abstract: A technique is designed for conducting a seismic survey. The technique utilizes a plurality of vibrator arrays employed to conduct a seismic survey utilizing low frequency and high frequency vibrators in each vibrator array. The plurality of vibrator arrays continuously sweeps low frequency signals via low frequency vibrators. While sweeping low frequency signals, high-frequency vibrators emit high-frequency signals in an alternating pattern between vibrator arrays to enhance the seismic survey.

Abstract: A technique facilitates the use of seismic data. The technique utilizes an autonomous underwater vehicle to obtain data on water column characteristics in a seismic survey area. The data can be used to adjust aspects of the seismic survey data and/or the seismic survey technique.

Abstract: A user interface display method that facilitates setting of various setting parameters for controlling an application program and preserving past values of the setting parameters as historical snapshots. When a setting panel is displayed and the user modifies setting parameter values in the setting panel and saves the new values, the pre-modified setting parameter values are saved as a historical snapshot, and the modified values are saved as the current setting parameters for controlling the program. Historical snapshots of setting panels that have been saved in the past can be displayed simultaneously with the current setting panel in a manner that visually simulates a stack of panels. The user can select any one of the historical panels in the stack, modify the setting values in that panel, and save the modified values as the current settings while keeping the historical snapshot.

Abstract: Methods, apparatuses, and systems are disclosed that assist in determining a location to acquire seismic data. In one embodiment, a method includes modeling acquisition of seismic data in a first location based on a first factor that impacts acquisition of seismic data in the first location. The method also includes generating a modeled attribute based on the modeling, and determining whether to acquire seismic data in the first location based on the modeled attribute or the first factor.

Abstract: Divergence data is received from a divergence sensor and seismic data is received from seismic sensors, where the divergence sensor and seismic sensors are part of a sensor assembly. A calibration term is computed based on combining the divergence data and the seismic data, where the calibration term includes a first parameter that is related to a characteristic of the sensor assembly, and a second parameter that is related to a characteristic of a near-surface subterranean medium.

Abstract: Implementations of various technologies for a method for generating a seismic image of a subsurface are described herein. Seismic data may be received from two sensors in a seismic survey. The seismic data below and equal to a predetermined frequency may be classified as low-frequency seismic data. The low-frequency seismic data may be re-sampled based on the predetermined frequency. A set of low-frequency Green's functions may be calculated using interferometry on the re-sampled low-frequency seismic data. High-frequency seismic data of the seismic data may be processed to create a set of high-frequency Green's functions at one or more source locations of the seismic survey. The set of high-frequency Green's functions may be merged with the set of low-frequency Green's functions to create a set of broad-band Green's functions. The seismic image may be generated using the set of broad-band Green's functions at the source locations.

Abstract: Measurement data acquired by at least one sensor in a cable structure towed through a body of water is received. A torsional vibration noise component in the measurement data is estimated. The torsional vibration noise component is used to estimate a rotation angle of the at least one survey sensor with respect to a reference coordinate system of the cable structure.

Abstract: Measurement data is received from first and second seismic sensors, where the first and second seismic sensors are oriented in opposite directions. Each of the first and second seismic sensors has a sensing element responsive to pressure and particle motion. The signals can be combined to remove the particle motion component of the measurement data and obtain pressure-only data. Alternatively, the signals can be combined to deghost the received measurement data.

Abstract: The invention comprises a system for attenuating noise in seismic signals detected in a marine seismic streamer. In a particular implementation the system may comprise seismic detectors positioned in the streamer and interconnected to form a plurality of wavenumber filters, with each of the wavenumber filters attenuating signals within a range of wavenumbers. The output signals from the wavenumber filters are operatively connected to a plurality of band-pass filters, and the output signals of the band-pass filters are combined by summation means. The range of wavenumbers attenuated by the wavenumber filters and the passbands of the band-pass filters are selected so that in the output signal of the summation means, signals within a selected frequency range of interest propagating along the cable within a selected velocity range are attenuated and signals within the selected frequency range of interest having a velocity range outside the selected velocity range are preserved.

Abstract: There is provided herein a system and method of seismic exploration that produces improved locations and timings for ocean bottom seismometers. The instant method utilizes linearized inversion in conjunction with a conventionally accurate clock to provide both time and positioning for each OBS unit with high accuracy as compared with the prior art approach. Inversion is one mathematical tool that effectively performs the requisite triangulation. Furthermore, the clock drift can be accounted for in the inversion scheme. The inversion not only determines the OBS position and shot timing errors, but also estimates the accuracy of the position and timing determination.

Abstract: The various embodiments of the present invention provide a method for removing a Scholte waves and similar ground roll type waves from a seismic sea bottom data in a shallow water. The method comprises acquiring seismic sea bottom data in a shallow waters, applying a time-frequency-wave number (t-f-k) transform on the acquired seismic sea bottom data, identifying a time-frequency relationship of a surface wave based on a specific wave number, identifying a frequency-wave number relationship of a surface wave based on a specific time, designing a time varying frequency-wave number filter in the time-frequency-wave number domain to separate the surface wave, applying a time varying frequency-wave number filtering process to remove an undesired energy and inversing a filtered record by applying an inverse S-Transform operation and an inverse Fourier Transform operation.

Abstract: Systems and methods for determining the far field signature of a source in wide azimuth surveys are disclosed. The method includes determining a position of a first sensor and a source. The first sensor is attached to a first vessel and the source is attached to a second vessel. The method further includes calculating a reflected incidence angle between the first sensor and the source, determining a position for a second sensor based on a direct incidence angle between the second sensor and the source approximating the direct incidence angle. The method also includes determining a far field signature for the source based on the direct incidence angle.

Abstract: A disclosed subsurface imaging method begins by obtaining initial signals from a geophysical survey that has been acquired with multiple geophysical energy sources actuated in a plurality of firing sequences, each sequence having a known time delay between the firing times of each source. The initial signals are grouped into gathers of signals acquired from multiple firing sequences. For each gather, initial estimates of the first and second source wave fields are determined. Quieted signals for the first source are then generated to represent the initial signals minus a current estimate of the second source wave field. A coherent energy separation operation is applied to the quieted signals to obtain a refined estimate for the first source wave field.

Abstract: Techniques are disclosed relating to the operation of a source umbilical cable without functioning power cables from the source umbilical cable. Techniques are disclosed relating to a source umbilical cable without a power cable (e.g., a cable configured or operable to supply electrical power), and an apparatus that includes a geophysical signal source (e.g., a seismic signal source) with an electrical power generating component. The apparatus may, in one embodiment, include a geophysical signal source with a local generator configured to supply electrical power to electrical components of the geophysical signal source. In another embodiment where the geophysical signal source is being towed behind a vessel, a generator of the geophysical signal source may generate and supply electrical power based on motion of the generator through a body of water.

Abstract: A method for surveying, may include receiving, by a processor, first survey data from a first source, the first source comprising a first signal generated by a subsurface earth formation in response to a passive-source electromagnetic signal, wherein the electromagnetic signal is generated by an electroseismic or seismoelectric conversion of the passive-source electromagnetic signal. The method may also include receiving, by the processor, second survey data from a second source and processing the first survey data and the second survey data to determine one or more properties of a subsurface earth formation.

Abstract: The disclosure presents computational systems and methods for attenuating noise in seismic data. The seismic data may be recorded by distributed sensors in response to acoustic signals emanating from one or more sources activated at approximately the same location with a time delay between activations of the one or more sources. The system and methods form an initial gather of traces from the seismic data and generate time-shifted gathers based on the initial gather and the time delays between activation of the sources. A realization gather is formed from traces selected from the initial gather and the time-shifted gathers. Noise in the seismic data is attenuated in the realization gather and may be removed. The realizations gathers may be used to generate high-resolution seismic images of the subterranean formation and enable quantitative seismic interpretation and improved reservoir monitoring.

Abstract: Method for acquiring, at reduced acquisition cost, seismic data using simultaneous, field-encoded sources in the field (702), and then constructing pseudo source-records (703) that better meet the requirements for using additional simultaneous computer-encoded sourcing for computer simulations or forward modeling (706) as part of (707) iterative FWI (Full Wavefield Inversion) or RTM (Reverse Time Migration), with additional reduction in computational costs. By better meeting the requirements of simultaneous sourcing for FWI or RTM (701), artifacts and crosstalk are reduced in the output. The method can be used for marine streamer acquisition and other non-fixed spread geometries to acquire both positive and negative offsets and to mitigate the “missing data” problem for simultaneous-source FWI. It can also be used for land data to overcome issues with moving spreads and long continuous records.

Abstract: A technique includes obtaining multi-component seismic data acquired by two or more seismic sensors while in tow. The multi-component seismic data is indicative of a pressure wavefield and particle motion. The technique includes based on the data, determining at least one high order (i.e., second order or higher) spatial derivative of the pressure wavefield.

Abstract: Method for acquiring zero offset data from a marine seismic survey. Seismic data are recorded using source signature monitor receivers located very near the air guns or other sources (81). The recorded data are sorted into common-source gathers (82). A common trace is computed that is common to each gather (83). The common trace is subtracted from each trace in each gather (84), resulting in approximately zero-offset data.

Abstract: Described are methods for obtaining seismic signals representative of properties of the earth's interior, including the steps of obtaining near-field acoustic signals recorded in the vicinity of a seismic source (13), muting from the near-field acoustic signals at least partly signals representing direct arrivals from the seismic source (13), and using a remaining part of the obtained signals as estimate of a zero-offset data set. The zero-off set data set can then be used to interpolate data from conventional acquisition location, such as streamers (11), to locations closer to the source (13).

Abstract: A method for processing seismic data. The method includes receiving the seismic data acquired by at least two receivers that are disposed at different depths. The method may then time-align the seismic data, collect a portion of the time-aligned seismic data into a gather and sum the collected time-aligned seismic data in the gather. After summing the collected time-aligned seismic data in the gather, the method may widen a spectrum of the summed seismic data and generate an image of subsurface formations in the earth based on the widened spectrum.