Abstract: A method for estimating noise in particle motion seismic recordings and upgoing (deghosted) and downgoing components of ecorded wavefields includes inputting pressure related and particle motion related seismic signals. A sparsity promoting transformation is applied to the input seismic signals. A matrix à and column vector {tilde over (b)} are constructed according to the expression: A ~ = ( I I 0 I - I ? ? I ) x ~ = ( d u n ) b ~ = ( A - 1 ? p A - 1 ? z ) , wherein d represents a down-going seismic wavefield, u represents an up-going seismic wavefield, n represents the noise and ? represents a user-chosen scalar to adjust emphasis of the noise.

Abstract: A method for modelling and migrating seismic data, that includes using an acoustic wave equation and a spatial distribution of one or more earth-model parameters. The acoustic wave equation is modified by including at least one secondary source term, and based on a seismic acquisition configuration, either calculating the seismic signals that would be detected from the modelled wavefield or migrating observed seismic signals or migrating residual signals as part of an inversion.

Abstract: A method for weathered layer correction of seismic data includes identifying arrival times in the seismic data corresponding to a weathered layer velocity gradient. A velocity model of the weathered layer is generated using the arrival times. The seismic data are time adjusted using the velocity model.

Abstract: A method for reducing effects of free surface multiple reflections from seismic signal measurements. The measurements result from seismic energy imparted into the Earth's subsurface from collocated measurements related to pressure and vertical component of motion in response to the imparted seismic energy. The method includes entering as input to a computer the measurements related to pressure and vertical component of motion. In the computer, a down-going component of the measurements is determined. An impulse response of the Earth in the absence of a free surface from the down-going component is determined.

Abstract: A method for estimating a far field seismic energy source signature includes using detected near field seismic signals corresponding to actuation of each one of a plurality of seismic energy sources in an array of seismic energy sources. The near field seismic signals are detected at two spaced apart locations in the near field of each seismic energy source, the at least two spaced apart locations being arranged such that a direction of propagation of the detected near field seismic signals is determinable from the detected near field signals. A notional source signature for each seismic energy source and a notional ghost for each seismic energy source using the detected near field seismic signals. A far field signature is determined for the plurality of seismic energy sources using the determined notional source signature and notional ghost signature from each seismic energy source.

Abstract: A method for determining seismic sensor depths in a body of water includes accepting as input to a computer measurements of seismic signals made by a plurality of seismic sensors disposed in a body of water. A depth increment and a range of sensor depths for correlation of signals from each of the plurality of seismic sensors is defined. In the computer, the input seismic measurements are extrapolated to each depth increment in the range. A depth of each seismic sensor is determined by correlating the seismic signal measurements with depth-extrapolated measurements of the seismic signal measurements.

Abstract: A method for deblending seismic signals includes entering as input to a computer recorded signals comprising seismic energy from a plurality of actuations of one or more seismic energy sources. A model of deblended seismic data and a blending matrix are initialized. A blending matrix inversion is performed using the initialized model. The inversion includes using a scaled objective function. The inversion is constrained by a thresholding operator. The thresholding operator is arranged to recover coefficients of the model of the deblended seismic data that are substantially nonzero, against a Gaussian white noise background. The thresholded model is projected into data space. Performing the blending matrix inversion is repeated if a data residual exceeds a selected threshold and the inversion is terminated if the data residual is below the selected threshold. At least one of storing and displaying an output of the blending matrix inversion is performed when the blending matrix inversion is terminated.

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

Abstract: A method for deblending seismic signals includes entering as input to a computer recorded signals comprising seismic energy from a plurality of actuations of one or more seismic energy sources. A model of deblended seismic data and a blending matrix are initialized. A blending matrix inversion is performed using the initialized model. The inversion includes using a scaled objective function. The inversion is constrained by a thresholding operator. The thresholding operator is arranged to recover coefficients of the model of the deblended seismic data that are substantially nonzero, against a Gaussian white noise background. The thresholded model is projected into data space. Performing the blending matrix inversion is repeated if a data residual exceeds a selected threshold and the inversion is terminated if the data residual is below the selected threshold. At least one of storing and displaying an output of the blending matrix inversion is performed when the blending matrix inversion is terminated.

Abstract: A method for attenuating multiple reflections from marine seismic signals includes estimating a multichannel prediction filter by minimizing energy between detected seismic signals and seismic signals representing water layer multiple reflections in combination with forcing a sparsity constraint on the estimated multichannel filter. Near offset seismic signals not present in the detected seismic signals are reconstructed by convolving the detected seismic signals with an inverse of the multichannel prediction filter. The multichannel prediction filter is convolved with the reconstructed near offset seismic signals to obtain a final multiple reflection model. The final multiple reflection model is subtracted from the detected seismic signals to obtain multiple reflection attenuated seismic signals.

Abstract: A method for estimating a far field seismic energy source signature includes using detected near field seismic signals corresponding to actuation of each one of a plurality of seismic energy sources in an array of seismic energy sources. The near field seismic signals are detected at two spaced apart locations in the near field of each seismic energy source, the at least two spaced apart locations being arranged such that a direction of propagation of the detected near field seismic signals is determinable from the detected near field signals. A notional source signature for each seismic energy source and a notional ghost for each seismic energy source using the detected near field seismic signals. A far field signature is determined for the plurality of seismic energy sources using the determined notional source signature and notional ghost signature from each seismic energy source.

Abstract: A method for determining seismic sensor depths in a body of water includes accepting as input to a computer measurements of seismic signals made by a plurality of seismic sensors disposed in a body of water. A depth increment and a range of sensor depths for correlation of signals from each of the plurality of seismic sensors is defined. In the computer, the input seismic measurements are extrapolated to each depth increment in the range. A depth of each seismic sensor is determined by correlating the seismic signal measurements with depth-extrapolated measurements of the seismic signal measurements.

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

Abstract: The present invention relates to processing of seismic data. More specifically, the present invention relates to processing of low-cut filtered seismic data to reduce or suppress transient effects.