Entries |
Document | Title | Date |
20080219095 | Technique and System to Cancel Noise from Measurements Obtained from a Multi-Component Streamer - A technique includes receiving a pressure measurement and a particle motion measurement from at least towed seismic sensor. The pressure measurement contains signal and noise. The technique includes estimating the signal in the pressure measurement and based at least on the estimated signal in the pressure measurement, estimating a noise in the pressure measurement. Noise in the particle motion measurement is predicted based on at least the estimated noise in the pressure measurement, and the particle motion measurement is processed to remove noise based on at least the predicted noise. | 09-11-2008 |
20080259726 | Mitigation of Noise in Marine Multicomponent Seismic Data through the Relationship between Wavefield Components at the Free Surface - A method and apparatus implementing a technique for mitigating noise in seismic data are presented. The technique includes estimating a noise component in a set of multicomponent seismic data representing a recorded wavefield from the relationship at the free surface of an upgoing component and a downgoing component decomposed from the recorded wavefield; and removing the estimated noise component from the seismic data. The noise component can be estimated by decomposing a recorded wavefield into an upgoing component and a downgoing component and isolating a noise component in the recorded wavefield from the relationship of the decomposed upgoing and downgoing components at the free surface. | 10-23-2008 |
20090040872 | Removing Vibration Noise from Multicomponent Streamer Measurements - A technique includes obtaining a particle motion measurement and a pressure gradient measurement, which were acquired by seismic sensors while in tow. The technique includes removing noise from one of the measurements, which includes scaling the measurements relative to each other and subtracting one of the measurements from the other measurement. | 02-12-2009 |
20090067285 | 3D DEGHOSTING OF MULTICOMPONENT OR OVER / UNDER STREAMER RECORDINGS USING CROSS-LINE WAVENUMBER SPECTRA OF HYDROPHONE DATA - A technique includes obtaining pressure data that was acquired by seismic sensors towed as part of a three-dimensional spread of streamers and obtaining particle motion data, which are indicative of particle motion at locations of the sensors. The technique includes estimating cross-line spectra of the pressure data based at least in part on the pressure data, and the technique includes deghosting the particle motion data based at least in part on the estimated cross-line spectra. | 03-12-2009 |
20090073805 | METHODS AND APPARATUS OF BOREHOLE SEISMIC SURVEYS - Methods and apparatus for borehole seismic survey are disclosed comprising a first seismic source under water at a first location and a second seismic source at a second, deeper location. Seismic signals from the seismic sources are recorded with synchronized sensors located in a borehole and source signature data are obtained by combining the recorded seismic signals such that low and high frequency content of the combined source signature data is extended relative to the source signature of the first seismic source and the second seismic source. | 03-19-2009 |
20090097356 | PROCESSING OF COMBINED SURFACE AND BOREHOLE SEISMIC DATA - Methods and related systems are described for processing surface seismic data. Surface seismic data representing seismic signals detected at a plurality of surface locations is wavefield deconvolved using a combination of direct wave travel times estimated from borehole seismic data, and wavefield energy estimated from the surface seismic data. | 04-16-2009 |
20090129202 | FAST 3-D SURFACE MULTIPLE PREDICTION - A method and apparatus for predicting a plurality of surface multiples for a plurality of traces in a record of seismic data. In one embodiment, the method includes providing a plurality of target traces at a nominal offset and a nominal azimuth; selecting a plurality of pairs of input traces, wherein the midpoints of the input traces in each pair are separated by half the nominal offset and the azimuth of a line connecting the midpoints of the input traces in each pair is equal to the nominal azimuth; convolving the selected pairs of input traces to generate a plurality of convolutions; and applying a three dimensional operator to the convolutions. | 05-21-2009 |
20090147621 | Method of attenuating noise in marine seismic streamers utilizing varied sensor spacing and position-dependent band-pass filters - 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. | 06-11-2009 |
20090161487 | TECHNIQUE AND SYSTEM TO CANCEL NOISE IN MEASUREMENTS PROVIDED BY SENSORS OF A MULTI-COMPONENT STREAMER - A technique includes determining a displacement of an acoustic sensor while in tow. Based on the determined displacement of the sensor, a measurement that is acquired by the sensor is compensated to remove noise from the measurement. | 06-25-2009 |
20090185444 | Method for wavefield separation in 3D dual sensor towed streamer data with aliased energy in cross-streamer direction - Pressure records and vertical particle velocity records from dual sensor towed streamer data are transformed to the inline wavenumber domain. A series of scaling filters are applied to the transformed vertical particle velocity records at each inline wavenumber, wherein each of the series of scaling filters is calculated for a different cross-streamer wavenumber range and in blocks of inline traces in which all seismic events are approximately linear. The pressure spectrum and the scaled vertical particle velocity spectrum are combined to separate upgoing and downgoing wavefield components. The separated upgoing and downgoing wavefield components are inverse-transformed back to the time-space domain. | 07-23-2009 |
20090238036 | DETERMINING DIRECTIONAL PROPAGATION ATTRIBUTES OF A SEISMIC EVENT - A technique includes obtaining seismic data acquired by at least one seismic sensor. The technique includes processing the seismic data to determine a value that is indicative of a three-dimensional directional propagation attribute of a seismic event based on the seismic data. | 09-24-2009 |
20090245022 | DUAL-WAVEFIELD MULTIPLE ATTENUATION - Method for attenuating surface multiple reflections in dual-wavefield seismic data. In one implementation, the method may include: (a) performing wavefield separation on dual-wavefield seismic data to separate events in the seismic data into data sets according to ghost characteristics; (b) applying a multidimensional Surface-Related Multiple Elimination (SRME) to two or more of the data sets to yield an SRME result in a manner that retains surface reflection information affecting surface multiple reflections; and (c) repeating step (b) one or more times. | 10-01-2009 |
20090251992 | Method for deghosting marine seismic streamer data with irregular receiver positions - Seismic data are obtained for each seismic source activation in a marine streamer and for each frequency, after being transformed to a spectral domain. An iterative conjugate gradient scheme, using a physically-based preconditioner, is applied to the transformed seismic data, to provide a least squares solution to a normal set of equations for a deghosting system of equations. The solution is inverse-transformed back to a space-time domain to provide deghosted seismic data. | 10-08-2009 |
20090296521 | NOISE REDUCTION IN PARTICLE MOTION SENSING SEISMIC STREAMER - An apparatus includes particle motion sensors and a streamer that contains the particle motion sensors. The streamer is to be towed in connection with a seismic survey, and the towing of the streamer produces a turbulent flow. The streamer includes an inner cable that contains the particle motion sensors and a fluid containing layer to surround the inner cable to reduce noise otherwise sensed by the particle motion sensors due to the turbulent flow. | 12-03-2009 |
20090316527 | IDENTIFICATION AND SUPPRESSION OF MULTIPLES IN OCEAN BOTTOM SEISMIC DATA - A method for identifying and suppressing water column reverberations (“multiple reflections”) in two-component ocean bottom seismic data is disclosed. The method involves processing the hydrophone (P) data and the geophone (Z) data separately to produce two stacked images of the subsurface. Analyzing the stacked P-image and the stacked Z-image together can be used to identify multiple reflections. Analyzing the stacked P-image and the stacked Z-image together with an image of the subsurface created from hydrophone and geophone data combined in the usual way (PZ-image) can be used to identify residual multiples in the PZ image. The stacked P and Z images can be combined using an existing PZ combination technique to suppress multiples. The efficiency of the PZ combination technique at suppressing multiples is increased because of the higher signal-to-noise ratio of stacked data. | 12-24-2009 |
20090323469 | TECHNIQUE AND SYSTEM TO INCREASE THE LENGTH OF A SEISMIC SHOT RECORD - A system includes an interface and a processor. The interface receives seismic datasets, which are associated with multiple firings of a set of at least one seismic source. Each dataset is acquired by seismic sensors during a different time period of a sequence of time periods that are limited by times at which the set of seismic source(s) are fired. The processor, for each of the firings of the set of seismic source(s), generates an associated shot record based on information contained at least two of the datasets. | 12-31-2009 |
20090323470 | Method for attenuation of multiple reflections in seismic data - A method for attenuating multiple reflections in seismic signals includes coherency filtering the seismic signals. The seismic signals are low pass filtered and high pass filtered seismic signals at a frequency selected such that substantially only multiple reflections exist in the seismic signals above the frequency. A mask is generated having unity value where the high pass filtered signal amplitude exceeds a selected threshold. The mask has unity zero value for all other filtered signals. The mask value is multiplied by the low pass filtered signals. The multiplied signals are added to the high pass filtered signals and a coherency filter is applied to remove remaining primary energy to generate a model of the multiple reflections. The multiple reflection model is subtracted from the coherency filtered seismic signals. | 12-31-2009 |
20100008186 | FLEXURAL WAVE ATTENUATION - A seismic information processing method and apparatus includes attenuating flexural wave noise information from seismic information. Flexural wave information removal includes receiving the seismic information using an information processing device interface, the seismic information having a plurality of directional components acquired using a multi-axis motion sensor coupled to ice floating on a body of water, the seismic information including desired seismic information and the flexural wave information. A noise model of the flexural wave information may be generated using at least one of the plurality of seismic information directional components using an information processing device. The noise model is improved using an adaptive correction filter, and the improved noise model is applied to at least one directional component of the received seismic information to attenuate the flexural wave information wave in the seismic information. | 01-14-2010 |
20100039891 | Attenuating seismic interference noise using a dual sensor recording system - A method for attenuating noise in marine seismic signals includes cross ghosting pressure responsive marine seismic signals and contemporaneously acquired motion responsive marine seismic signals. A difference is determined between the cross ghosted signals. The difference is used to attenuate noise in at least one of the pressure responsive signals and the motion responsive signals. | 02-18-2010 |
20100054080 | Determining Seismic Streamer Array Geometry And Seismic Sensor Response Using Dual Sensor Seismic Streamer Arrays - A method for marine seismic surveying includes determining at least an initial depth of a plurality of spaced apart seismic sensors in a body of water. The sensors each include a substantially collocated pressure responsive sensor and motion responsive sensor. A ghost time delay is determined for each sensor based on the at least an initial depth. Seismic signals detected by each motion responsive sensor and each pressure responsive sensor are cross ghosted. The at least initial depth is adjusted, and the determining ghost time delay and cross ghosted seismic signals are repeated until a difference between the cross ghosted motion responsive signal and the cross ghosted pressure responsive signal falls below a selected threshold. | 03-04-2010 |
20100054081 | Method of summing dual-sensor towed streamer signals using cross-ghosting analysis - A merged particle velocity signal is generated by combining a recorded vertical particle velocity signal, scaled in an upper frequency range using a time-dependent arrival angle as determined by cross-ghosting analysis, with a simulated particle velocity signal, calculated in a lower frequency range from a recorded pressure signal using a time-varying filter based on the time-dependent arrival angle. Combined pressure and vertical particle velocity signals are generated from the recorded pressure and merged particle velocity signals. | 03-04-2010 |
20100091610 | Method for imaging a sea-surface reflector from towed dual-sensor streamer data - A pressure wavefield and a normal velocity wavefield measured on a smoothly shaped acquisition surface by towed dual-sensor marine seismic streamers are decomposed into up-going and down-going pressure and particle velocity components on an observation level between the acquisition surface and a sea surface of undetermined shape. The up-going and down-going pressure and particle velocity components are extrapolated iteratively in steps from the observation level toward the sea surface. An image point and a reflection coefficient of the sea surface at the image point are determined from the iteratively extrapolated up-going and down-going pressure and particle velocity components. | 04-15-2010 |
20100097886 | Method for determining formation quality factor from dual-sensor marine seismic signals - A method for estimating formation quality factor includes determining an upgoing pressure wavefield of seismic signals recorded using a collocated pressure responsive sensor and motion responsive sensor deployed in a body of water The upgoing wavefield has spectral effect of water surface ghosting attenuated by combining the pressure responsive signals and motion responsive signals. The quality factor is determined by determining a difference in amplitude spectra between a first seismic event and a second seismic event in the upgoing pressure wavefield. | 04-22-2010 |
20100118647 | Method for optimizing energy output of from a seismic vibrator array - A method for generating seismic energy for subsurface surveying includes operating a first seismic vibrator and operating at least a second seismic vibrator in a body of water substantially contemporaneously with the operating the first seismic vibrator. Each vibrator has a different selected frequency response, and the vibrators each are operated at a depth in the water such that a surface ghost amplifies a downward output of each vibrator within a selected frequency range. A signal used to drive each vibrator has a frequency range corresponding to the frequency range of each vibrator. | 05-13-2010 |
20100124148 | Method for optimum combination of pressure and particle motion sensors for a 3-D spread of dual-sensor marine seismic streamers - A method for determining upgoing pressure components of seismic signals from signals detected by combined pressure responsive sensors and motion responsive seismic sensors disposed in a plurality of laterally spaced apart streamers includes determining a threshold time at which angle of incidence error in the motion responsive signals in the cross-line direction falls below a selected threshold. Below the threshold time, the motion responsive signals are corrected for angle of incidence in the in-line and cross-line directions. Above the threshold time, the motion responsive signals are corrected for angle of incidence only in the in-line direction. Both sets of incidence corrected measured motion responsive signals, and the pressure responsive signals are used to determine upgoing or downgoing pressure components or upgoing or downgoing motion components of the measured motion responsive and pressure responsive seismic signals. | 05-20-2010 |
20100124149 | Method of wavefield extrapolation for single-station, dual-sensor towed streamer signals - A time-dependent arrival angle is determined at a single receiver station in a towed streamer. Up-going and down-going pressure wavefields are calculated from pressure and vertical particle velocity wavefields measured at the receiver station. Extrapolated up-going and down-going pressure wavefields are generated from the up-going and down-going pressure wavefields displaced by a time delay based upon the time-dependent arrival angle. | 05-20-2010 |
20100135114 | WAVEFIELD EXTRAPOLATION MODELING FOR INTERNAL MULTIPLE PREDICTION - Methods for attenuating multiple reflections in seismic data by predicting the multiples using wavefield extrapolation modeling, which uses one-way wavefield propagation in both the up and down directions to predict internal multiples up to a specified order. | 06-03-2010 |
20100202251 | USING A ROTATION SENSOR MEASUREMENT TO ATTENUATE NOISE ACQUIRED BY A STREAMER-DISPOSED SENSOR - A technique includes receiving data indicative of a first measurement acquired by a rotation sensor on a seismic streamer and based on the first measurement, estimating a torque noise present in a measurement acquired by a second sensor on the streamer. The technique includes attenuating the torque noise based on the estimate. | 08-12-2010 |
20100246324 | MULTIPLE ATTENUATION FOR OCEAN-BOTTOM SEISMIC DATA - Multiple Modeling, wherein the wavefield is separated into up/down wavefield on either source-side or receiver-side; wherein WEMM is used to extrapolate and predict multiples, which are attenuated from OBC seismic data. | 09-30-2010 |
20110038228 | METHOD OF MARINE TIME-LAPSE SEISMIC SURVEYING - A method of marine time-lapse seismic surveying of a subsurface formation, comprises providing a baseline survey, providing a monitor survey that includes information about changes in the subsurface relative to the baseline survey, recording a repeat survey so closely in time to one of either the baseline survey or the monitor survey that changes in the subsurface can be ignored but under different near-surface conditions from said one survey, computing a short-time survey difference between the repeat signals and signals comprising said one of either the baseline survey or the monitor survey, computing a monitor survey difference, matching the short-time survey difference and the monitor survey difference to derive a matched noise survey difference, subtracting the matched noise survey difference from the monitor survey difference, and outputting a noise suppressed survey difference based on the result of the subtraction. | 02-17-2011 |
20110051551 | Sensor grouping for dual sensor marine seismic streamer and method for seismic surveying - A method for marine seismic surveying includes towing a streamer in a body of water. The streamer includes a plurality of spaced apart sensor groups, each including a plurality of longitudinally spaced apart pressure sensors and particle motion responsive sensors. Signals are detected at each of the sensors in response to actuation of a seismic energy source. Components of the sampled motion signals in each group above a selected frequency are combined to generate respective group motion signals. Components of the motion responsive signals below the selected frequency are velocity filtered. The velocity filtered signals are combined with the group motion signals to generate full bandwidth motion responsive signals corresponding to each sensor group. | 03-03-2011 |
20110058450 | Method for deghosting and water layer multiple reflection attenuation in marine seismic data - A method is disclosed for deghosting and water surface multiple reflection attenuation in marine seismic data. The method includes decomposing data acquired at two water depths with sensors that measure the same parameter into upgoing and downgoing wavefield components. The decomposing includes, in one embodiment, transforming the data into the spatial Fourier domain and separating the upgoing and downgoing wavefield components in the transformed data. A substantially multiple-free wavefield is then determined from the decomposed wavefield components. | 03-10-2011 |
20110063948 | Method for combining signals of pressure and particle motion sensors in marine seismic streamers - A cross-line slowness is determined for each sample in the signals in towed marine seismic streamers. A range of assumed cross-line slownesses is selected. Vertical wavenumbers are determined using the range of assumed cross-line slowness determined for samples in the signals of pressure sensors and particle motion sensors in the towed marine seismic streamers. The determined vertical wavenumbers are used to correct the particle motion sensor signals for angle of incidence along the direction of the seismic streamers and transverse thereto to generate a corrected particle motion sensor signal. The corrected particle motion sensor signals are combined based on the determined cross-line slowness for the samples. The corrected particle motion sensor signal and the pressure sensor signal are used to determine at least one of upgoing and downgoing pressure components and upgoing and downgoing particle motion components of the particle motion sensor and pressure sensor seismic signals. | 03-17-2011 |
20110085414 | Flexural Wave Attenuation - A seismic information processing method and apparatus includes attenuating flexural wave noise information from seismic information. Flexural wave information removal includes receiving the seismic information using an information processing device interface, the seismic information having a plurality of directional components acquired using a multi-axis motion sensor coupled to ice floating on a body of water, the seismic information including desired seismic information and the flexural wave information. A noise model of the flexural wave information may be generated using at least one of the plurality of seismic information directional components using an information processing device. The noise model is improved using an adaptive correction filter, and the improved noise model is applied to at least one directional component of the received seismic information to attenuate the flexural wave information wave in the seismic information. | 04-14-2011 |
20110103181 | System and Technique to Suppress the Acquisition of Torque Noise on a Multi-Component Streamer - A technique includes distributing particle motion sensors along the length of a seismic streamer. Each particle motion sensor is eccentrically disposed at an associated angle about an axis of the seismic streamer with respect to a reference line that is common to the associated angles. The sensors are mounted to suppress torque noise in measurements that are acquired by the particle motion sensors. This mounting includes substantially varying the associated angles. | 05-05-2011 |
20110103182 | Removing Noise from a Seismic Measurement - A technique includes spatially filtering a signal that is derived from a seismic acquisition. The filtering is associated with a filter length, and the filtering includes varying the filter length with frequency. The filtering may be used in connection with adaptive noise attenuation, which is applied to decomposed subbands. Furthermore, the filtering may be applied during the reconstruction of the signal from the subbands. | 05-05-2011 |
20110103183 | System and Technique to Increase the Spacing of Particle Motion Sensors on a Seismic Streamer - A technique includes receiving data indicative of non-uniformly spaced samples of particle motion wavefield acquired by particle motion sensors while in tow. The samples are spaced apart by an average spacing interval, which is not small enough to prevent vibration noise from being aliased into a signal cone for a first signal formed from samples of the particle motion wavefield having a uniform spacing at the average spacing interval. The technique includes processing the data to generate a second signal that is indicative of the particle motion wavefield and does not have aliased vibration noise in the signal cone. | 05-05-2011 |
20110110189 | Method for full-bandwidth deghosting of marine seismic streamer data - Seismic data recorded in a marine streamer are obtained, with the seismic data being representative of characteristics of subsurface earth formations and acquired by deployment of a plurality of seismic receivers overlying an area of the subsurface earth formations to be evaluated, the seismic receivers generating at least one of an electrical and optical signal in response to seismic energy. A complex Laplace frequency parameter is used to transform the seismic data from a space-time domain to a spectral domain. An iterative conjugate gradient scheme, using a physically-based preconditioner, is applied to the transformed seismic data, to provide a least squares solution to a normal set of equations for a deghosting system of equations. The solution is inverse-transformed back to a space-time domain to provide deghosted seismic data, which is useful for imaging the earth's subsurface. | 05-12-2011 |
20110134718 | Method for full-bandwidth source deghosting of marine seismic streamer data - Seismic data recorded in a marine streamer are obtained, sorted as a common receiver gather. A complex Laplace frequency parameter is used to transform the seismic data from a space-time domain to a spectral domain. An iterative conjugate gradient scheme, using a physically-based preconditioner, is applied to the transformed seismic data, to provide a least squares solution to a normal set of equations for a source deghosting system of equations. The solution is inverse-transformed back to a space-time domain to provide source deghosted seismic data, which is useful for imaging the earth's subsurface. | 06-09-2011 |
20110176385 | DUAL-SENSOR NOISE-REDUCTION SYSTEM FOR AN UNDERWATER CABLE - A system and a method for rejecting noise in an underwater sensor cable, such as a towed streamer or an ocean-bottom cable. An adaptive hydrodynamic model of the cable produces an estimated sensor signal from a raw sensor signal from a particle-motion sensor, such as an accelerometer. The estimated sensor signal represents an estimate of the response of the underwater cable to cable motion absent seismic events. A noise-reduced response to particle motion alone is produced by subtracting the estimated sensor signal from the raw sensor signal to reject cable motion and other noise effects in the raw sensor signal. A seismic event detector uses a hydrophone signal from an acceleration-canceling hydrophone to disable the adapting of the hydrodynamic model during seismic events. The hydrophone signal is combined with the response to particle motion by PZ summation to produce a deghosted seismic response signal. | 07-21-2011 |
20110182139 | INTERPOLATION AND DEGHOSTING OF SEISMIC DATA ACQUIRED IN THE PRESENCE OF A ROUGH SEA - A technique for processing seismic data acquired in a seismic survey conducted in the presence of a rough sea includes receiving a first dataset that is derived from data acquired by a first set of seismic sensors generally towed at a first depth in the seismic survey and receiving a second dataset that is derived from data acquired by a second set of seismic sensors generally towed at a second depth that is different than the first depth in the seismic survey. The first dataset is indicative of at least pressure measurements, and the second dataset is indicative of at least crossline particle motion measurements. The technique includes determining crossline particle motion measurements in the presence of a relatively flat sea surface based at least in part on the crossline measurements that are indicated by the second dataset and the pressure measurements that are indicated by the first dataset. | 07-28-2011 |
20110182140 | SEISMIC SYSTEM WITH GHOST AND MOTION REJECTION - An underwater seismic system for reducing noise due to ghost reflections or motion through the water from seismic signals. The system includes two motion sensors. One sensor has a first response and is sensitive to platform-motion-induced noise as well as to acoustic waves. The other sensor has a different construction that isolates it from the acoustic waves so that its response is mainly to motion noise. The outputs of the two sensor responses are combined to remove the effects of motion noise. When further combined with a hydrophone signal, noise due to ghost reflections is reduced. | 07-28-2011 |
20110292762 | Deghosting Seismic Data - A technique includes receiving seismic data acquired by seismic sensors; and processing the seismic data on a machine to deghost the data. The processing includes deghosting the seismic data using a first deghosting technique that relies on a ghost model; deghosting the seismic data using a second deghosting technique that is independent from any modeling of the ghost; and selectively combining the results of the deghosting using the first and second deghosting techniques. | 12-01-2011 |
20110305108 | DEGHOSTING USING MEASUREMENT DATA FROM SEISMIC SENSORS - 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. | 12-15-2011 |
20110305109 | METHOD AND APPARATUS FOR DEGHOSTING SEISMIC DATA - 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. | 12-15-2011 |
20120026830 | METHODS AND SYSTEMS TO ELIMINATE UNDESIRABLE VARIATIONS IN TIME-LAPSE SEISMIC SURVEYS - Device and method for processing 4-dimensional (4-D) seismic traces. The method includes receiving at least two vintages of seismic traces recorded by seismic receivers for a same subsurface area, wherein said seismic receivers are located at the ocean floor; applying up-down deconvolution to each of said vintages of seismic traces to obtain a representation of a reflectivity of said subsurface area from each vintage of seismic traces; and redatuming the up-down deconvolution result of each vintage from the ocean floor to a desired water depth of the ocean to reduce one or more changes in said seismic traces associated with water layer variations between recordings of said series of seismic traces. The redatumed seismic data is used to generate one or more images representing characteristics of said subsurface area. | 02-02-2012 |
20120033527 | FAST 3-D SURFACE MULTIPLE PREDICTION - A method and apparatus for predicting a plurality of surface multiples for a plurality of traces in a record of seismic data. In one embodiment, the method includes providing a plurality of target traces at a nominal offset and a nominal azimuth; selecting a plurality of pairs of input traces, wherein the midpoints of the input traces in each pair are separated by half the nominal offset and the azimuth of a line connecting the midpoints of the input traces in each pair is equal to the nominal azimuth; convolving the selected pairs of input traces to generate a plurality of convolutions; and applying a three dimensional operator to the convolutions. | 02-09-2012 |
20120039149 | Method for separating seismic sources in marine seismic surveys - An operator is applied in a frequency domain to multiple source seismic data acquired in a marine survey, with multiple sources substantially horizontally collocated and at different depths, to generate an estimate of a primary source wavefield, the operator constructed to compensate for time delays between and for different depths of the primary and secondary sources. The primary source wavefield estimate is adaptively subtracted from the multiple source seismic data to generate secondary source wavefield estimates. Another operator is applied in the frequency domain to the secondary source wavefield estimates to generate another primary source wavefield estimate, the operator constructed to compensate for time delays between and for different depths of the primary and secondary sources. The primary and secondary source estimates are used, after further iterative refinements to remove noise, to generate upgoing and downgoing wavefield components of the multiple source seismic data. | 02-16-2012 |
20120044782 | Method for swell noise detection and attenuation in marine seismic surveys - Spatial data sequences are extracted in a frequency-space domain at selected frequencies in selected data windows in seismic data. A signal model and residuals are iteratively constructed for each extracted spatial data sequence. Each data sample in each extracted spatial data sequence is assessed to determine if the data sample is noisy. Each noisy data sample in each data sequence is replaced by a corresponding signal model value. The earth's subsurface is imaged using the noise-attenuated seismic data. | 02-23-2012 |
20120057430 | MULTI-COMPONENT, ACOUSTIC-WAVE SENSOR AND METHODS - A multi-component sensor of a fluid-borne acoustic wave that senses pressure and up to three orthogonal particle motion components. The sensor is unresponsive to motion of the sensor mount. Furthermore, the sensor is substantially unresponsive to the turbulent flow of the acoustic medium past the sensor. | 03-08-2012 |
20120081999 | Interferometric Seismic Data Processing for a Towed Marine Survey - A method for processing seismic data. The method includes receiving the seismic data acquired at two or more sensors on a towed marine survey and regularizing the received seismic data into a spatial domain. After regularizing the seismic data, the method includes classifying the regularized seismic data below and equal to a predetermined frequency as low-frequency seismic data. The method then calculates a set of low-frequency Green's functions using interferometry on the low-frequency seismic data described above. The method then processes high-frequency seismic data of the seismic data to create a set of high-frequency Green's functions at one or more source locations of the towed marine survey. After creating the set of high-frequency Green's functions, the method merges the set of low-frequency Green's functions and the set of high-frequency Green's functions to create a set of broad-band Green's functions at the source locations. | 04-05-2012 |
20120082000 | System and Technique to Suppress the Acquisition of Torque Noise on a Multi-Component Streamer - A technique includes receiving particle motion data acquired by particle motion sensors while in tow. The particle motion data are indicative of a seismic signal and a torque noise, and the particle motion sensors are oriented to modulate a wavenumber of a first component of the torque noise away from a signal cone that is associated with the seismic signal. The technique includes estimating the first component of the torque noise and based at least in part on the estimated first component, estimating a second component of the torque noise inside the signal cone. The technique includes suppressing the second component of the torque noise based at least in part on the estimated second component. | 04-05-2012 |
20120082001 | Monitoring the Quality of Particle Motion Data During a Seismic Acquisition - A technique includes acquiring particle motion data from a plurality of particle motion sensors while in tow during a seismic survey. During the seismic survey, the particle motion data are processed without deghosting the particle motion data to determine whether at least some portion of the particle motion data is inadequate for an application that relies on the particle motion data. | 04-05-2012 |
20120140592 | 3D DEGHOSTING OF MULTICOMPONENT OR OVER/UNDER STREAMER RECORDINGS USING CROSS-LINE WAVENUMBER SPECTRA OF HYDROPHONE DATA - A technique includes obtaining pressure data that was acquired by seismic sensors towed as part of a three-dimensional spread of streamers and obtaining particle motion data, which are indicative of particle motion at locations of the sensors. The technique includes estimating cross-line spectra of the pressure data based at least in part on the pressure data, and the technique includes deghosting the particle motion data based at least in part on the estimated cross-line spectra. | 06-07-2012 |
20120163122 | Removing Noise from a Seismic Measurement - A technique includes decomposing a signal that is derived from a seismic acquisition into a plurality of signals such that each signal is associated with a different frequency band. For each signal of the plurality of signals, the technique includes performing the following: decomposing the signal into subbands in successive stages, where the subbands are associated with at least different frequency ranges of the signal; selectively applying adaptive noise attenuation in between the successive stages such that the stages decompose noise-attenuated subbands; and reconstructing the signal from the subbands resulting from the decomposition. The technique includes combining the reconstructed signals. | 06-28-2012 |
20120213032 | METHOD FOR PZ SUMMATION OF 3-DIMENSIONAL WIDE AZIMUTH RECEIVER GATHERS AND DEVICE - Apparatus, computer instructions and method for de-pegging seismic data related to a subsurface of a body of water. The method includes receiving as input recorded seismic data (H, G), wherein the recorded seismic data is recorded with a receiver having at least three components; extracting a three-dimensional (3D) gather from the recorded seismic data (H, G); separating up-going and down-going components (U, D) from the 3D gather using a 3D calibration operator (G | 08-23-2012 |
20120213033 | METHOD AND APPARATUS FOR DEGHOSTING SEISMIC DATA - 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. | 08-23-2012 |
20130021873 | METHOD AND DEVICE FOR WAVE FIELDS SEPARATION IN SEISMIC DATA - Apparatus, computer instructions and method for processing seismic data related to a subsurface of a body of water. The method includes receiving input data for a vertical direction and radial direction and/or from a hydrophone, applying a radon transform to the input data, separating primary signals from ghosts signals based on the vertical and radial components, applying an inverse radon transform to determine up-going and down-going wave fields in a time-distance domain, and separating interfering up-going and down-going wave fields that are recorded by the same receivers. | 01-24-2013 |
20130028049 | METHOD FOR HANDLING ROUGH SEA AND IRREGULAR RECORDING CONDITIONS IN MULTI-SENSOR TOWED STREAMER DATA - Rough sea elevation is estimated from a high-frequency portion of recorded pressure data and recorded vertical velocity component data. Generalized deghosting and datuming operators are constructed, which take into account the estimated rough sea elevation and irregular recording depth conditions. A low-frequency portion of the recorded pressure data is decomposed into up-going and down-going wavefields on a horizontal reference plane, using the generalized datuming and deghosting operators. A low-frequency portion of the vertical velocity component data is reconstructed from the decomposed up-going and down-going wavefields on the horizontal reference plane, using the generalized datuming and deghosting operators. | 01-31-2013 |
20130028050 | DETERMINING AN ORIENTATION ANGLE OF A SURVEY SENSOR - 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. | 01-31-2013 |
20130077436 | DEVICE AND METHOD TO DETERMINE SHAPE OF STREAMER - A method for determining a shape of a streamer to be towed under water for collecting seismic data. The method includes receiving a velocity model for the subsurface; selecting a first profile for a streamer to be used to survey the subsurface; calculating ghosts and/or residual ghosts and/or residual ghost spectra for a plurality of reflectors of the subsurface; and determining that the first profile is appropriate for surveying the subsurface when at least one criterion, related to the ghosts, residual ghosts and/or residual ghost spectra is met. | 03-28-2013 |
20130083625 | DEMODULATING A WAVEFIELD - A technique includes demodulating a wavefield; generating spatial samples of the demodulated wavefield; and processing the samples to extract spectral components of the wavefield based at least in part on the demodulating. | 04-04-2013 |
20130100767 | SEISMIC ACQUISITION USING SOLID STREAMERS - An embodiment of the disclosed invention includes a method for attenuating noise during acquisition of marine seismic date. The method includes placing a seismic streamer in a body of water. The seismic streamer includes a streamer body having a length and a channel, a seismic sensor disposed within the channel, and a gel disposed within the channel. The gel has a complex viscosity of at least 50 Pascals and includes a concentration of a polymer between the range of about 5% and about 25% by weight. The method also includes placing a source in the body of water. The seismic streamer and the source are towed through the body of water and the source is fired while being towed through the body of water. Data is collected from the seismic streamer as it is towed through the body of water. | 04-25-2013 |
20130107664 | PROCESSING MULTI-COMPONENT SEISMIC DATA | 05-02-2013 |
20130121109 | METHOD AND SYSTEM FOR SEPARATING SEISMIC SOURCES IN MARINE SIMULTANEOUS SHOOTING ACQUISITION - Seismic data are obtained by recording simultaneously in seismic streamers, 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 residual 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. | 05-16-2013 |
20130135966 | Acquisition and Processing of Multi-Source Broadband Marine Seismic Data - A method and a system of acquiring and processing multi-source broadband marine seismic data in such a way that at least a part of said acquired data is partially or fully de-ghosted on the receiver side and then partially or fully re-assembled to a pre-stack dataset. At least one non-uniformly horizontal streamer is towed and at least two seismic sources emit seismic signals at spaced apart positions. Further presented is a method of processing marine seismic data by using the thus resulting notch diversity in these two (or more) seismic records to de-ghost the dataset, gathering two or more recorded seismic signals having substantially the same source-sensor offset and substantially the same common mid-point at different sensor depths, the sensor depths at least different enough to enable identification of seismic signals originating from ghosting. The gather is de-ghosted, thus obtaining seismic data with significantly broader bandwidth. | 05-30-2013 |
20130155811 | WAVE-FIELDS SEPARATION FOR SEISMIC RECORDERS DISTRIBUTED AT NON-FLAT RECORDING SURFACES - Apparatus, computer instructions and method for separating up-going and down-going wave fields (U, D) from seismic data recorded within or beneath a body of water, or in general below the surface of the earth. The method includes a step of receiving seismic data (P | 06-20-2013 |
20130163376 | Device and Method for Deghosting Variable Depth Streamer Data - Computing device, computer instructions and method for deghosting seismic data related to a subsurface of a body of water. The method includes receiving seismic data recorded by seismic receivers that are towed by a vessel, wherein the seismic data is recorded in a time-space domain and the seismic receivers are located at different depths (z | 06-27-2013 |
20130163377 | DEVICE AND METHOD FOR DENOISING OCEAN BOTTOM DATA - Computing device, computer instructions and method for denoising marine seismic data recorded with first and second seismic sensors. The method includes receiving first seismic data recorded with the first sensor in a time-space domain; receiving second seismic data recorded with the second sensor in the time-space domain, calculating with a processor models of the first and second seismic data in a transform domain that is different from the time-space domain; calculating in the transform domain an energy related to a down-going energy based on the models of the first and second seismic data; determining a noise in the transform domain corresponding to the second seismic data based on the calculated energy; reverse transforming the noise from the transform domain into the time-space domain; and denoising the second seismic data by subtracting the noise in the time-space domain from the second seismic data. | 06-27-2013 |
20130163378 | DEVICE AND METHOD FOR DENOISING OCEAN BOTTOM DATA - Computing device, computer instructions and method for denoising marine seismic data recorded with first and second seismic sensors. The method includes receiving first seismic data recorded with the first sensor in a time-space domain; receiving second seismic data recorded with the second sensor in the time-space domain, wherein the first and second seismic data are recorded at the same locations underwater; calculating with a processor models of the first and second seismic data in a transform domain that is different from the time-space domain; performing a wavefield separation using the first and second datasets in the transform domain; determining a noise in the transform domain corresponding to the second seismic data based on the wavefield separation; reverse transforming the noise from the transform domain into the time-space domain; and denoising the second seismic data by subtracting the noise in the time-space domain from the second seismic data. | 06-27-2013 |
20130163379 | DEVICE AND METHOD FOR PROCESSING VARIABLE DEPTH STREAMER DATA - Computing device, computer instructions and method for deghosting seismic data related to a subsurface of a body of water. The method includes receiving seismic data recorded by seismic receivers that are towed by a vessel, wherein the seismic data is recorded in a time-space domain; modeling the seismic data in a shot or common midpoint domain as a function of operators to derive a model; using the derived model to remove the receiver ghost from the seismic data to obtain deghosted seismic data; and generating a final image of the subsurface based on the deghosted seismic data. | 06-27-2013 |
20130176818 | VARIABLE DEPTH STREAMER SRME - Methods and systems for variable wavelet correction are described. A variable depth dataset is deghosted before presentation to a multiples prediction step of multiples elimination model. In another aspect, the multiples prediction is reghosted before presentation to and adaptive subtraction step of the multiples elimination model. A source-side zero-phasing signature can be applied before deghosting and a predefined gain can be applied in the low and high frequency sides as part of deghosting and reghosting to compensate for the squaring effect produced by convolving wavelets. | 07-11-2013 |
20130182533 | ATTENTUATING NOISE ACQUIRED IN AN ENERGY MEASUREMENT - A technique includes receiving data corresponding to at least one measurement of energy produced by a shot of an energy source; and transforming the received data to a domain that is sensitive to event direction. The technique includes comparing the measurement(s) with a reference based at least in part on the transformation; and based at least in part on the comparison, attenuating noise from the measurement(s). | 07-18-2013 |
20130182534 | DEVICE AND METHOD FOR REMOVAL OF MULTIPLES FROM SEISMIC DATA VINTAGES - A method, an apparatus and a computer readable medium for generating an image of a subsurface based on seismic data corresponding to at least two different times, for a same surveyed area are provided. A cost function, which is a sum over the seismic data vintages of a norm of differences between data and model predicted multiples, is minimized subject to minimizing residual multiples that are differences of corresponding multiples belonging to different vintages among the seismic data vintages. | 07-18-2013 |
20130182535 | SEISMIC DATA PROCESSING INCLUDING INTERNAL MULTIPLE MODELING WITHOUT SUBSURFACE INFORMATION - A system and method are disclosed for substantially eliminating the influence of internal multiples when seismic mapping under-water geographical areas of interest without a priori knowledge of subsurface information. The system and method iteratively locate multiple-generating horizons for predicting internal multiples and uses a lower-higher-lower relationship between the multiple generating horizons. The system and method provide an appropriate and cost-effective means for internal multiple attenuation without subsurface information. | 07-18-2013 |
20130182536 | WAVEFIELD DEGHOSTING - 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. | 07-18-2013 |
20130201791 | METHOD AND SYSTEM FOR DETERMINING SOURCE SIGNATURES AFTER SOURCE GHOST REMOVAL - Seismic data are acquired using a seismic source comprising a plurality of seismic sub-sources disposed in a body of water at a plurality of depths and activated with different time delays. Far-field signatures are determined for the plurality of seismic sub-sources at each of the plurality of depths. A composite ghost-free far-field signature of the seismic source is determined from the far-field signatures for the plurality of seismic sub-sources at each of the plurality of depths and different time delays. A source response is removed from the seismic data using the far-field signatures of the seismic source | 08-08-2013 |
20130201792 | METHOD AND APPARATUS FOR PROCESSING SEISMIC DATA - Methods, apparatuses, and systems are disclosed for processing seismic data. In some embodiments, a set of vectorial measurements and a set of corresponding scalar measurements of a seismic wavefield may be obtained at a seismic receiver. An angle of incidence of the seismic wavefield at a first instance of time may be determined by calculating an incidence vector of the seismic wavefield at the seismic receiver at the first instance of time, with the incidence vector derived from a measure of correlation of at least one of the vectorial measurements. A component of a vectorial measurement may be corrected with the determined angle of incidence of the seismic wavefield at the first instance of time, and the corrected component may be combined with a scalar measurement that corresponds to the first instance of time. | 08-08-2013 |
20130208566 | METHOD FOR PROCESSING DUAL-SENSOR STREAMER DATA WITH ANTI-ALIAS PROTECTION - Dual-sensor seismic data are separated into aliased and unaliased parts in a frequency-wavenumber domain. The seismic data in the unaliased part are processed using a conventional vertical wavenumber. The seismic data in the aliased part are processed using an alternative vertical wavenumber additionally based on a Nyquist wavenumber for the seismic data. The processed unaliased seismic data and the processed aliased seismic data are combined. | 08-15-2013 |
20130242696 | PRIMARY ESTIMATION ON OBC DATA AND DEEP TOW STREAMER DATA - Method for correcting OBC or deep-towed seismic streamer data for surface-related multiple reflections. The measured pressure data, preferably after conditioning ( | 09-19-2013 |
20130250721 | MARINE SEISMIC SURVEYING EMPLOYING INTERPOLATED MULTICOMPONENT STREAMER PRESSURE DATA - It is described a method of interpolating and extrapolating seismic recordings, including the steps of deriving particle velocity related data from seismic recordings obtained by at least one streamer carrying a plurality of multi-component receivers and using the particle velocity related data to replace higher derivatives of pressure data in an expansion series. | 09-26-2013 |
20130279290 | DEVICE AND METHOD FOR DEGHOSTING VARIABLE DEPTH STREAMER DATA - Computing device, computer instructions and method for deghosting seismic data related to a subsurface of a body of water. The method may include receiving input seismic data recorded by seismic receivers that located at different depths (z | 10-24-2013 |
20130279291 | ACQUIRING NEAR-ZERO OFFSET SURVEY DATA - To acquire near-zero offset survey data, a survey source and a first streamer attached to the survey source are provided, where the first streamer has at least one survey receiver. A second streamer separate from the survey source and the first streamer includes survey receivers. Near-zero offset data is measured using the at least one survey receiver of the first streamer. | 10-24-2013 |
20130286777 | METHODS AND APPARATUS FOR GENERATING DEGHOSTED SEISMIC DATA - One embodiment relates to a method for deghosting seismic data from a marine seismic survey. The seismic data from the marine seismic survey is obtained, where the marine seismic survey was performed using multiple sub-sources towed at two or more different depths and fired at distinct time-delays. The seismic data is sorted into common receiver gathers, and the common receiver gathers are transformed from horizontal source coordinates to horizontal wavenumbers. For each selected frequency, a matrix operator is constructed, and an inversion procedure is applied to a system of equations based on the matrix operator to generate source-deghosted seismic data. Other embodiments, aspects and features are also disclosed. | 10-31-2013 |
20130301386 | METHOD, DEVICE AND PROCESSING ALGORITHM FOR MULTIPLE AND NOISE ELIMINATION FROM MARINE SEISMIC DATA - Computing device, computer instructions and method for simultaneously denoising and attenuating multiples in seismic data recorded with seismic receivers. The method includes receiving the seismic data, wherein the seismic data includes a pressure P component and a vertical Z component; separating the seismic data into up-going U wave-fields and down-going D wave-fields; calculating an up-down deconvolution R based on the up-going U and the down-going D wave-fields; generating a multiple model M based on the up-down deconvolution R; and adaptively subtracting the multiple model M from the pressure P component to obtain a corrected pressure P | 11-14-2013 |
20130322208 | METHODS AND SYSTEMS FOR IMAGING SUBTERRANEAN FORMATIONS WITH PRIMARY AND MULTIPLE REFLECTIONS - Systems and methods for imaging subterranean formations using primary and multiple reflections are described. An exploration-seismology vessel tows a seismic source, a receiver acquisition surface located beneath a free surface, and a source acquisition surface positioned at a depth below the source. The receiver acquisition surface is used to measure pressure and normal velocity wavefields and the source acquisition surface is used to measure direct, down-going, source pressure wavefields generated by the source. The down-going source pressure wavefields in combination with the down-going pressure wavefields and up-going pressure wavefields computed from the pressure and velocity wavefields are used to compute images of the subterranean formation associated with primary reflections and multiple reflections. | 12-05-2013 |
20130329520 | Surface-Related Multiple Elimination For Depth-Varying Streamer - Techniques are described for predicting surface-related multiples from measurements performed at varying depths. One or more operations, such as wavefield decompositions and/or extrapolations, may be performed on scattered wavefield data obtained by underwater sensors at different underwater depths to determine one or more surface-related multiple wavefield contributions at a selected depth or at the different underwater depths where the scattered wavefield data is collected from measurements. | 12-12-2013 |
20130329521 | VARIABLE DEPTH STREAMER SRME - Methods and systems for variable wavelet correction are described. A variable depth dataset is deghosted before presentation to a multiples prediction step of multiples elimination model. In another aspect, the multiples prediction is reghosted before presentation to and adaptive subtraction step of the multiples elimination model. A source-side zero-phasing signature can be applied before deghosting and a predefined gain can be applied in the low and high frequency sides as part of deghosting and reghosting to compensate for the squaring effect produced by convolving wavelets. | 12-12-2013 |
20130343154 | SEISMIC DATA PROCESSING INCLUDING COMPENSATING FOR SOURCE AND RECEIVER GHOST EFFECTS IN REVERSE TIME MIGRATION - Methods and systems for compensating for source and receiver ghost effects in a reverse time migration (RTM) equation are described. Boundary conditions associated with the RTM acoustic wave equations for the source and recorded wavefields are modified. The resultant modified RTM acoustic wave equations are solved to generate ghost compensated modeled seismic images. In another aspect an imaging condition is also modified and the resultant RTM acoustic wave equations are solved to generate velocity and impedance perturbation images. | 12-26-2013 |
20130343155 | SYSTEM AND TECHNIQUE TO SUPPRESS THE ACQUISITION OF TORQUE NOISE ON A MULTI-COMPONENT STREAMER - A technique includes distributing particle motion sensors along the length of a seismic streamer. Each particle motion sensor is eccentrically disposed at an associated angle about an axis of the seismic streamer with respect to a reference line that is common to the associated angles. The sensors are mounted to suppress torque noise in measurements that are acquired by the particle motion sensors. This mounting includes substantially varying the associated angles. | 12-26-2013 |
20140016436 | METHODS AND SYSTEMS FOR RECONSTRUCTION OF LOW FREQUENCY PARTICLE VELOCITY WAVEFIELDS AND DEGHOSTING OF SEISMIC STREAMER DATA - Computational methods and systems for deghosting marine seismic streamer data are described. In particular, an exploration-seismology vessel tows a number of streamers that form a data acquisition surface located beneath a free surface. The methods computationally deghost or substantially remove receiver ghost signals from seismic data recorded by steamer receivers. The deghosting methods include low frequency compensation to recover vertical velocity wavefield information that is typically lost due to a low signal-to-noise ratio over a low frequency range independent of the free surface conditions or the shape of the data acquisition surface. | 01-16-2014 |
20140022860 | WAVE FIELD SEPARATION BY MIXED DOMAIN INVERSION - Methods, devices, and computer-readable media are provided for accessing seismic data that describes seismic energy that propagated through media, including water and optionally surface or subsurface layers, to measurement locations in the water. The seismic data includes pressure data that describes time-variant pressures at measurement locations in the water. The seismic data may also include velocity data that describes time-variant velocities of particles at measurement locations in the water. The seismic data is processed using wavefield decomposition to reduce an effect of a portion of the seismic energy that reflects off of the surface of the water. The processing is performed in a discrete domain that includes or is the measurement locations. The discrete domain may exclude certain locations or ranges of locations. The processed seismic data may be used to generate a map of any surfaces of the media through which the seismic energy propagated. | 01-23-2014 |
20140036626 | ESTIMATING AND USING SLOWNESS VECTOR ATTRIBUTES IN CONNECTION WITH A MULTI-COMPONENT SEISMIC GATHER - A technique includes determining at least one attribute of a slowness vector associated with a seismic gather based on pressure data and an indication of particle motion that is measured by at least one seismic sensor while in tow. | 02-06-2014 |
20140050049 | METHODS AND SYSTEMS FOR DEGHOSTING MARINE SEISMIC DATA - A method is provided for deghosting marine seismic data. Marine seismic data is provided. The marine seismic data has a total acoustic wavefield that includes an upgoing acoustic wavefield and a downgoing acoustic wavefield. A deghosting operation to determine a part of the total acoustic wavefield corresponding to one of the upgoing acoustic wavefield and the downgoing acoustic wavefield is performed. The deghosting operation accounts for a varying vertical distance between a detector of a streamer and a sea surface. One of the upgoing and downgoing acoustic wavefields in the total acoustic wavefield is identified based on a result of the deghosting operation. The downgoing acoustic wavefield is removed from the total acoustic wavefield. | 02-20-2014 |
20140064027 | HORIZONTAL STREAMER BROADBAND MARINE SEISMIC ACQUISITION CONFIGURATION AND PROCESSING - A method for de-ghosting marine seismic trace data is described. A reference seismic trace and a candidate seismic trace are selected from acquired seismic data. The acquired seismic data is gathered using a configuration wherein either a first streamer and a second streamer are disposed at different depths relative to one another and are laterally offset relative to one another, or using a configuration wherein a first source and a second source are disposed at different depths relative to one another and are laterally offset from one another. The reference seismic trace and the candidate seismic trace are processed, e.g., to perform normal moveout correction and/or vertical datum shifting, and the processed reference seismic trace is de-ghosted using the processed, candidate seismic trace. | 03-06-2014 |
20140140172 | DEGHOSTING MEASURED SURVEY DATA - Propagation of wavefields are simulated along paths in a survey environment, where the simulated propagation includes an influence of a reflection at an interface that causes ghost data in measured survey data. Deghosting of the measured survey data is performed using the simulated wavefields. | 05-22-2014 |
20140153363 | SYSTEMS AND METHODS FOR REMOVAL OF SWELL NOISE IN MARINE ELECTROMAGNETIC SURVEYS - Methods and systems for determining and removing swell noise from electric field data collected from streamers towed at different are disclosed. In one aspect, a first set of streamers called upper streamers is towed at a shallow depth, and the second set of streamers called lower streamers is towed below the upper streamers. Receivers located along the streamers measure surrounding electric fields and produce electric field signals. A proportionality parameter is calculated as a function of the electric field signals generated by vertically aligned receivers. The proportionality parameter can be used to calculate an approximate swell noise that is used to remove swell noise from electric field data measured by the receivers. | 06-05-2014 |
20140198612 | GHOST COMPENSATION IN BEAM MIGRATION - Methods and systems for ghost compensation which are embedded in beam migration are described. The ghost compensation is based on the fact that the beam migration is performed in the slant-stack domain. The trace data is transformed to a mid-point slant-stack frequency domain where a deghosting operator is applied and then the deghosted trace data is inverse transformed to a time domain. The time domain trace data can then be further processed as desired. | 07-17-2014 |
20140198613 | SYSTEM AND METHOD FOR THE REMOVAL OF SHALLOW WATER MULTIPLES USING A HYBRID MULTI-CHANNEL PREDICTION METHOD - A system and method are provided for determining shallow water multiples when seismically exploring a geographical area of interest under a body of water. The system and method estimate a multi-channel prediction operator F using a model of water layer related multiples with respect to received and stored seismic data, estimate a travel time of the transmitted seismic wavelets from the one or more sources to each of the plurality of receivers, and then generate water layer primary reflections models using the estimated travel time and Green's function. The system and method then merge the generated water layer primary reflections models with the multi-channel prediction operator F to create a hybrid multi-channel prediction operator F | 07-17-2014 |
20140219052 | SYSTEMS AND METHODS FOR DETECTING SWELL NOISE IN A SEISMIC GATHER - 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. | 08-07-2014 |
20140241124 | METHOD AND APPARATUS FOR MULTI-COMPONENT DATUMING - Methods, apparatuses, and systems are disclosed for datuming multi-component seismic data. In one example of such a method, a plurality of seismic traces are accessed, the plurality of seismic traces including data representative of amplitude and spatial gradient samples of a seismic wavefield at a plurality of recording locations in a medium. Using a computer-based processing unit, a wavefield propagation from the plurality of recording locations through a medium is initialized, using the amplitude and spatial gradient samples of the seismic wavefield. Seismic traces are generated that correspond to the propagated wavefield at defined locations within the medium. | 08-28-2014 |
20140269182 | SYSTEMS AND METHODS FOR REMOVING ACQUISITION RELATED EFFECTS FROM SEISMIC DATA - Systems and methods for operating a seismic source to attenuate shot generated noise, or residual energy from previous activation of the source, in recorded seismic data are described. In one aspect, methods operate a single seismic source towed through a body of water along a survey track. As the survey vessel travels along the survey track, the source is activated at the end of randomly selected time delays, resulting in attenuation of shot generated noise. The method also attenuates other forms of coherent noise that align from shot to shot. | 09-18-2014 |
20140269183 | SYSTEMS AND METHODS FOR FREQUENCY-DOMAIN FILTERING AND SPACE-TIME DOMAIN DISCRIMINATION OF SEISMIC DATA - Computational systems and methods that combine global frequency-wavenumber-domain (“f-k domain”) filters with localized eigenimage based event selection to generate a resulting wavefield with reduced filter imprints on gather edges, reduced noise, and correct treatment of aliased energy are disclosed. The methods are executed by applying filters to the full set of seismic gather data in the f-k domain in order to obtain a resulting wavefield from recorded pressure and/or particle velocity data. The output of the filter is iteratively decomposed according to local dip values using eigenimage processing based on singular value decomposition (“SVD”). The same sample locations are extracted using SVD from the input in addition to generating input for a subsequent iteration with already processed data removed. Eigenimage processing methods allow for correct treatment of spatially aliased energy in f-k domain filtering. | 09-18-2014 |
20140286127 | PROCESSING SEISMIC DATA TO ATTENUATE VIBRATION NOISE - A technique includes receiving first data acquired by at least a particle motion gradient sensor or a rotation sensor of a streamer that is subject to vibration due to towing of the streamer; and receiving second data acquired by at least one particle motion sensor of the streamer and being indicative of particle motion and vibration noise. The technique includes processing the second data in a processor-based machine to, based at least in part on the first data, attenuate the vibration noise indicated by the second data to generate third data indicative of the particle motion. | 09-25-2014 |
20140286128 | SYSTEMS AND METHODS FOR PERFORMING DUAL-SCALE INTERPOLATION - Systems and methods are provided for processing seismic data and displaying an output associated with the seismic data. A method includes: separating the seismic data into a fine-scale dataset and a coarse-scale dataset, wherein each dataset includes a non-zero portion of the data; applying a first interpolation to the coarse-scale dataset which results in an interpolated coarse-scale dataset; applying a second interpolation to the fine-scale dataset which results in an interpolated fine-scale dataset, wherein the first and second interpolation are different interpolations; summing together the interpolated coarse-scale dataset and the interpolated fine-scale dataset which results in a summed interpolated dataset; and displaying at least one image based on the summed interpolated dataset. | 09-25-2014 |
20140369164 | REMOVING NOISE FROM A SEISMIC MEASUREMENT - A technique includes spatially filtering a signal that is derived from a seismic acquisition. The filtering is associated with a filter length, and the filtering includes varying the filter length with frequency. The filtering may be used in connection with adaptive noise attenuation, which is applied to decomposed subbands. Furthermore, the filtering may be applied during the reconstruction of the signal from the subbands. | 12-18-2014 |
20150009780 | METHOD AND APPARATUS FOR RECEIVER-SIDE DEGHOSTING OF SEISMIC DATA - Apparatus, computer instructions and method for combining first and second records to form a substantially deghosted seismic record. | 01-08-2015 |
20150293250 | METHOD AND SYSEM FOR SEPARATING SEISMIC SOURCES IN MARINE SIMULTANEOUS SHOOTING ACQUISITION - 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. | 10-15-2015 |
20160003957 | DIRECT ARRIVAL SIGNATURE ESTIMATES - Method for estimating source signature of a marine seismic source array in a naturally band-limited subsurface region, for designature processing of resulting seismic data. Direct arrivals identified in the streamer receivers' records ( | 01-07-2016 |
20160018545 | SEISMIC SENSOR DEVICES, SYSTEMS, AND METHODS INCLUDING NOISE FILTERING - 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. | 01-21-2016 |
20160018546 | MARINE SEISMIC SURVEYING INCLUDING DIRECT FAR FIELD MEASUREMENTS - A method of measuring seismic signals generated by marine acoustic sources includes deploying at least one seismic sensor unit to a location on a floor of a body of water within a survey area, and recording seismic signals that include a real measured far field signature generated by a seismic source during a marine seismic survey. The method further includes automatically actuating a retrieval device to cause the at least one seismic sensor unit to rise to the surface, in response to expiration of the selected time period or an actuation signal from the surface, retrieving the at least one seismic sensor unit from the surface, and processing seismic data collected from the return signal. Processing including identifying a far field signature of the seismic source based on the signals detected by the seismic sensor, and designaturing the seismic data based on the far field signature. | 01-21-2016 |
20160047929 | METHODS AND SYSTEMS THAT COMBINE WAVEFIELDS ASSOCIATED WITH GENERALIZED SOURCE ACTIVATION TIMES AND NEAR-CONTINUOUSLY RECORDED SEISMIC DATA - Systems and methods to correct source responses and perform source deghosting of a pressure or particle motion wavefield recorded using near-continuous recording of seismic data along a vessel track with generalize source activation times. The methods and systems receive a near-continuously recorded seismic data and generate a near-continuous wavefield for approximately stationary-receiver locations. Time windows of different temporal lengths are applied to traces of the near-continuous wavefield in approximately stationary-receiver locations in order to compute common-receiver gathers. The common-receiver gathers are corrected source wavefield response and source ghost effects and are combined in weighted sums to generate broadband seismic data. | 02-18-2016 |
20160047930 | Method For Acquiring and Processing Marine Seismic Data to Extract and Constructively Use the Up-Going and Down-Going Wave-fields Emitted by the Source - A method for marine seismic surveying includes separating up-going and down-going wavefields from seismic energy emitted by at least one marine seismic energy source. The separated up-going and down-going wavefields are propagated from the at least one marine seismic energy source to at least one of a water surface and a common reference depth. One of the up-going and down-going wavefields is phase shifted 180 degrees. The propagated, phase shifted up-going and down-going wavefields are summed. | 02-18-2016 |
20160047931 | MARINE DETERMINISTIC NOTCH COMPENSATION - A method of performing notch compensation and a system to perform notch compensation for a first seismic streamer are described. The method includes disposing the first seismic streamer at a first depth, where the seismic streamer includes a first set of sensors to receive reflections resulting from a seismic source, the reflections indicating a notch at a frequency. The method also includes disposing a second seismic streamer at a second depth, the second depth being less than the first depth and the second seismic streamer including a second set of sensors to receive reflections resulting from the seismic source. The method further includes processing the reflections received by the first set of sensors and the second set of sensors together to derive the match filter, and applying the match filter to the reflections received by the first set of sensors of the first seismic streamer to compensate for the notch. | 02-18-2016 |
20160054465 | SEISMIC DATA SPECTRUM RESTORING AND BROADENING - A method of spectrum restoring and broadening to produce high resolution seismic data from a plurality of shot records in a seismic survey is described. The method includes the steps of: dividing each shot record into a plurality of windows, in which each of the relevant variables is practically constant, and wherein each window contains one or more trace segments; forward modelling of spectral signatures for any ghost reflections in the shot records using a best estimate of all known parameters, such that every trace segment will have an observed and a (prior) modelled spectral signature; calculating an inverse operator to correct the spectral notches in every trace segment using a constrained set of final fitted values for all the relevant variables; and, recombining the processed trace segments to produce a final set of shot records whereby, in use, the deleterious effects of the ghost reflections in the shot records can be substantially eliminated. Amplitude and phase errors, both within a single shot record and between shots, due to ghost reflections can be corrected. | 02-25-2016 |
20160109594 | METHODS AND SYSTEMS THAT ATTENUATE NOISE IN SEISMIC DATA - Methods and systems that attenuate noise in seismic data. In one aspect, noise attenuation methods iteratively generate a low-speed noise model of low-speed noise recorded in the seismic data. The seismic data is arranged into a sparse seismic-data matrix. Low-speed noise refers to noise that propagates at speeds less the speed of sound in water. The low-speed noise model includes the low-speed noise and includes interpolated low-speed noise that approximates portions of the low-speed noise typically affected by spatial aliasing and streamer surface irregularities. The low-speed noise model may be subtracted from the sparse seismic-data matrix to obtain a noise-attenuated sparse seismic-data matrix. | 04-21-2016 |
20160109596 | SENSOR RECEIVER NULLS AND NULL STEERING - A method. In one embodiment there is provided a method in which a direction from a sensor position to a noise source is determined. A coordinate rotation is applied to a first set of signal values, wherein each signal value of the first set of signal values is based on an output of a corresponding component of a three-component particle motion sensor at the sensor position. The applying generates a rotated set of signal values. The coordinate rotation comprises a coordinate rotation transforming a first set of coordinate axes to a second set of coordinate axes, wherein the first set of coordinate axes has each coordinate axis aligned with a corresponding component of the three-component particle motion sensor at the sensor position, and the second set of coordinate axes comprises a first axis pointed in a direction opposite the direction from the sensor position to the noise source. | 04-21-2016 |
20160109601 | METHOD OF ACQUIRING GHOST-FREE SIGNATURES FOR BROADBAND SOURCE CALIBRATION - Embodiments described herein provide a method for acquiring de-ghosted data that can be utilized for calibration of a seismic source (air gun) model. Positions of a plurality of seismic receivers can be determined to enable efficient removal of an interference effect of ghost signals originating from mirrored versions of at least one seismic source that are received at the plurality of seismic receivers (hydrophones). Data (de-ghosted or near de-ghosted) can be acquired from the plurality of seismic receivers located at the determined positions by operating the at least one seismic source. A calibrated model of the at least one seismic source can be prepared based on the acquired (de-ghosted) data. | 04-21-2016 |
20160131784 | METHOD AND SYSTEM FOR SIMULTANEOUS ACQUISITION OF PRESSURE AND PRESSURE DERIVATIVE DATA WITH GHOST DIVERSITY - 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. | 05-12-2016 |
20160170054 | WAVEFIELD SEPARATION BASED ON A MATCHING OPERATOR BETWEEN SENSOR RESPONSES IN MULTI-COMPONENT STREAMERS | 06-16-2016 |
20160170057 | DEGHOSTING SURVEY DATA | 06-16-2016 |
20160178774 | METHODS AND SYSTEMS TO DETERMINE GHOST OPERATORS FROM MARINE SEISMIC DATA | 06-23-2016 |
20160187514 | SEISMIC ACQUISITION METHOD AND APPARATUS - 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. | 06-30-2016 |
20160202367 | NOISE REDUCTION IN A PARTICLE MOTION SENSING SEISMIC STREAMER | 07-14-2016 |
20160377756 | SEPARATION OF UP-GOING AND DOWN-GOING WAVEFIELDS INCLUDING THE DIRECT ARRIVAL - At least some embodiments are directed to a system. The system includes a processor and a memory coupled to the processor. The memory stores a program that, when executed by the processor, causes the processor to calculate a pressure response of a first sensor, and correct pressure wavefield data obtained from the first sensor responsive to a first acoustic wavefield. The correction is based on the calculated pressure response of the first sensor. The pressure response of the first sensor is responsive to a second acoustic wavefield having a propagation path between a source of the second acoustic wavefield and the first sensor, in which the propagation path includes no reflection from a subsurface formation. | 12-29-2016 |