Patent application number | Description | Published |
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 |
20100329079 | Method for dynamic aperture determination for three-dimensional surface-related multiple elimination - Dips are calculated for a series of sets of adjacent multiple contribution traces, from seismic data representative of subsurface formations, in the vicinity of a boundary of an aperture of a multiple contribution gather, the seismic data acquired by deploying a plurality of seismic sensors proximate an area of the earth's subsurface to be evaluated, the seismic sensors generating at least one of an electrical and optical signal in response to seismic energy. The boundary of the aperture of the multiple contribution gather is recursively extended, based on the calculated dips. Multiple contribution traces in the multiple contribution gather with the extended aperture boundary are stacked to generate predicted multiple traces. The predicted multiple traces are subtracted from the seismic data to generate surface-related multiple attenuated data useful for imaging the subsurface formations. | 12-30-2010 |
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 |
20110178712 | Azimuth correction for data reconstruction in three-dimensional surface-related multiple prediction - A best fitting trace in seismic data is determined for a desired trace to be reconstructed. An azimuth correction is calculated for the azimuth difference between the best fitting trace and the desired trace. The azimuth correction is applied to the best fitting trace to reconstruct the desired trace for 3D surface-related multiple prediction. | 07-21-2011 |
20110178715 | DIP-based corrections for data reconstruction in three-dimensional surface-related multiple prediction - A best fitting trace in seismic data is determined for a desired trace to be reconstructed. A dip-based correction is calculated per trace and per sample for differences in azimuth, common midpoint coordinates, and offset between the best fitting trace and the desired trace. The dip-based correction is applied to the best fitting trace to reconstruct the desired trace for 3D surface-related multiple prediction. | 07-21-2011 |
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 |
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 |
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 |
20140278114 | WAVEFIELD REGULARIZATION BY 3-D WAVEFIELD DECOMPOSITION FOR GEOPHYSICAL DATA - One embodiment relates to a method of wavefield regularization for geophysical data acquisition of seismic geophysical data. Measured traces, are obtained from an array of sensors. For each grid point on a processing grid, best-fitting traces of the measured traces are found. Using the best-fitting traces, spectral amplitudes of down-going and up-going wavefields are computed. The down-going and up-going wavefields are subsequently transformed to an output grid in a space-time domain. Another embodiment relates to an apparatus for wavefield regularization of geophysical data acquisition. Other embodiments, aspects and features are also disclosed. | 09-18-2014 |