Abstract:
Estimating an earthresponsecan includedeconvolving a multi-dimensional source wavefieldfrom near-continuously recorded seismic data recorded ata receiver position. The deconvolving can include spreading the near-continuously recorded seismic dataacross a plurality ofpossible source emission angles. The result of the deconvolution can bethe earth response estimate.
Abstract:
A method for use in marine seismic surveying includes: towing at least a portion of a marine seismic survey spread; imparting a composite swept seismic signal from the marine seismic survey spread, the composite swept seismic signal including a plurality of randomized subsweeps having different frequencies relative to one another and being emitted in parallel; and receiving a respective return for each of the subsweeps.
Abstract:
Various implementations described herein are directed to a seismic sensor device, which includes a housing and at least two pressure sensors coupled to the housing that are spaced apart by a separation distance. The difference in pressure signals between the at least two pressure sensors is configured to be used to reconstruct pressure signals at locations other than where the at least two pressure sensors are located.
Abstract:
A method for use in surveying a subsurface region beneath a body of water by detecting S waves propagating through the subsurface region. The method comprises using a first sensor configuration to detect mixed S and P waves on or in the subsurface region, using a second sensor configuration located on or in relatively close proximity to the subsurface region to detect P waves in the water, and using the P waves detected in the water to compensate the detected mixed S and P waves, and thereby attenuate the effects of P waves in the mixed S and P waves.
Abstract:
Controller and method for determining a driving signal of a vibro-acoustic source element that is configured to generate acoustic waves in water. The method includes estimating at least one physical constraint of the vibro-acoustic source element; modeling a ghost function determined by a surface of the water; setting a target energy spectrum density to be emitted by the vibro-acoustic source element during the driving signal; and determining the driving signal in a controller based on at least one physical constraint, the ghost function, and the target energy spectrum density.
Abstract:
A technique provides a source design and method for increasing low frequency output of a marine source array. The approach comprises providing a plurality of airguns. At least some of the airguns are activated to generate an effective bubble energy. The effective bubble energy may be optimized through use, preparation and/or arrangement of the airguns.
Abstract:
A method for processing seismic data. The method includes receiving the seismic data acquired at one or more receivers due to one or more marine vibroseis sources that emit one or more vibroseis sweeps. The method then applies a receiver motion correction algorithm to the received seismic data to generate receiver motion corrected seismic data. After generating the receiver motion corrected seismic data, the method transforms the receiver motion corrected seismic data into a temporal Fourier domain to generate seismic data as a function of frequency. The method then reconstructs the transformed seismic data as a function of frequency to correct for one or more motions of the one or more marine vibroseis sources. After reconstructing the transformed seismic data, the method transforms the reconstructed seismic data to the time domain. The method then generates a seismic image of a subsurface of the Earth based on the transformed reconstructed seismic data.
Abstract:
A method is disclosed for determining timing error between segments of a marine seismic survey (Fig. 2). The method includes picking arrival times of a water bottom reflection event in a plurality of seismic signals acquired in a plurality of seismic survey segments (16). A discontinuity in the picked arrival times is determined between at least two survey segments at locations corresponding to substantially the same water bottom reflection points (42-48). An amount of time adjustment is determined for at least one of the survey segments based on the discontinuity (52).
Abstract:
A method is described for separating the unknown contributions of two or more sources from a commonly acquired wavefield including the determination of a wavenumber dependent model which reconstructs the wavefield of the sources independently, below a frequency set by the slowest physical propagation velocity and applying an inversion based on the model, to the commonly acquired wavefield to separate the contributions.
Abstract:
A method includes receiving a seismic dataset from a survey, wherein the seismic dataset represents a portion of a subsurface geological formation and includes primary and multiple data. The method further includes the steps of conditioning the seismic dataset and estimating a model of the multiple data in the conditioned seismic dataset based on a user-defined parameter to derive a primary data set. Further, the method includes the steps of computing a velocity model from the primary data set using the user-defined parameter and updating the estimated multiple model based at least on a modification of the user-defined parameter. In addition, the method includes the steps of recomputing the primary data and the velocity model based on the modified user-defined parameter and generating an image of the primary data.