Westerngeco L.l.p.

Western Atlas International, Inc.

Baker Hughes Corporation

Western Geophysical Company of America

William Henry Dragoset, Jr

Ian Moore

Craig J Beasley

Zeljko Jericevic

Paolo Terenghi

Ronald E Chambers

Clement Kostov

Frederick James Barr

Philip Kitchenside

Richard Bisley

Alan Gaither Teague

Robert Ian Bloor

Antoun Salama

Kuang-Hung Liu

Louis Joseph Ward

Dennis L Cumro

A method for removing seismic noise from an input seismic trace. The method may receive the input seismic trace. The method may receive one or more noise references for the input seismic trace. The method may receive one or more filters corresponding to the noise references. The method may apply a nonlinear function to the input seismic trace and to the one or more noise references to produce respective output signals for the input seismic trace and for the one or more noise references. The nonlinear function may be capable of determining higher-order statistics. The method may update the filters based on increasing one or more information attributes of the output signals to a predetermined threshold. The method may then filter noise corresponding to the noise references.

Seismic noise removal

A method and apparatus for predicting interbed multiples is described herein. Trace geometries may be generated for one or more desired shot-side traces, one or more desired receiver-side traces, and one or more desired interbed multiple generator traces, for a first target trace. A first set of reflections at the interbed multiple generator layer may be extracted from one or more recorded traces closest to the desired interbed multiple generator traces. A second set of reflections below the interbed multiple generator layer may be extracted from one or more recorded traces closest to the desired shot-side traces. A third set of reflections below the interbed multiple generator layer may be extracted from one or more recorded traces closest to the desired receiver-side traces. The interbed multiples for the first target trace may be estimated based on the first set, the second set, and the third set.

Interbed multiple prediction

A technique includes determining at least one parameter that characterizes a seismic survey in which multiple interfering seismic sources are fired and seismic sensors sense energy that is produced by the seismic sources. The determination of the parameter(s) includes optimizing the seismic survey for separation of the sensed energy according to the seismic sources.

Optimizing a seismic survey for source separation

A method for processing seismic data. The method may include receiving seismic data due to a plurality of seismic sources and applying a first operator to the seismic data to generate a first estimate of seismic data. The method may then include applying a second operator to the first estimate of seismic data to generate residual seismic data due to one or more seismic sources. The method may determine a second estimate of seismic data based on the first estimate and the residual seismic data. The method may then process the second estimate of seismic data due to each seismic source to determine the presence of hydrocarbon deposits in a subterranean area of the earth.

Separating interfering signals in 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.

Multiple attenuation for ocean-bottom seismic data

A method for predicting a plurality of surface multiples for a plurality of target traces in a record of seismic data acquired in a survey area. The method includes selecting a target trace and identifying two or more desired traces for multiple prediction based on the target trace. After identifying the desired traces, the method identifies one or more recorded traces for each desired trace. Each identified recorded trace is described as being substantially close to one of the desired traces. The method then includes correcting the identified recorded traces for one or more geometry-related effects associated with the survey area and convolving the corrected recorded traces to generate a plurality of convolutions. After convolving the corrected recorded traces, the method then stacks the convolutions.

Correcting geometry-related time and amplitude errors

A technique includes obtaining seismic data acquired by seismic sensors of a composite seismic signal that is produced by the firings of multiple seismic sources. The technique includes modeling the seismic data as being a function of models for the sources and linear operators and defining desired constraints on the models. The technique includes simultaneously determining the models based on the modeling and the desired constraints. The datasets are generated based on the determined models. Each dataset is indicative of a component of the composite seismic signal and is attributable to a different one of the seismic sources.

Separating seismic signals produced by interfering seismic sources

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.

Dual-wavefield multiple attenuation

A method and apparatus for predicting a plurality of surface multiples for a plurality of target traces in a record of seismic data. In one embodiment, the method includes creating a file containing information regarding a plurality of pairs of recorded traces. Each pair of recorded traces is substantially closest to a desired shot-side trace and a desired receiver-side trace. The method further includes convolving the pairs of recorded traces to generate a plurality of convolutions and stacking the convolutions for each target trace.

Generalized 3D surface multiple prediction

Method for computing one or more timing errors that occur in one or more multiples predicted by a multiple prediction algorithm. The method includes the steps of generating one or more actual three-dimensional primary travel times and one or more actual three-dimensional multiple travel times, applying the multiple prediction algorithm to the actual three-dimensional primary travel times to generate one or more travel times for the multiples predicted by the multiple prediction algorithm, and subtracting the actual three-dimensional multiple travel times from the travel times for the multiples predicted by the multiple prediction algorithm.

Method for computing and using timing errors that occur in multiples predicted by multiple prediction algorithm

A method for improving vibratory source seismic data uses a filter which converts a recorded seismic groundforce signal (including harmonic distortion therein) into a desired short-duration wavelet. A plurality of surveys may be carried out using a plurality of sweeps from plurality of vibrators that have their relative phases encoded, the groundforce signal of each vibrator being measured. The recorded seismic reflection signals are then processed to separate out the signals from each vibrator. In another aspect, harmonics of upto any desired order may be canceled while carrying out multiple surveys with a plurality of vibrators. In a marine environment, the recorded signal from a vibrator towed by a moving vessel is used to derive a Doppler shift correction filter that is applied to reflection seismic data.

Seismic data acquisition and processing using non-linear distortion in a

A marine seismic signal is transformed from time domain into frequency domain and represented by matrix D. The marine data signal is truncated in time, transformed into the frequency domain and represented by matrix D.sub.T Eigenvalue decomposition D.sub.T=S.LAMBDA.S.sup.-1 of matrix D.sub.T is computed. Matrix product D S is computed and saved in memory. Conjugate transpose [D S]* is computed and saved in memory. Matrix product [D S]*[D S] is computed and saved in memory. Matrix inverse S.sup.-1 is computed and saved in memory. Conjugate transpose (S.sup.-1)* is computed and saved in memory. Matrix product S.sup.-1 (S.sup.-1)* is computed and saved in memory. An initial estimate of the source wavelet w is made. Source wavelet w is optimized by iterating the steps of computing the diagonal matrix [I-w.sup.-1 .LAMBDA.], computing matrix inverse [I-w.sup.-1 .LAMBDA.].sup.-1, computing conjugate transpose [(I-w.sup.-1 .LAMBDA.).sup.-1 ]*, retrieving matrix products [D S]*[D S] and S.sup.-1 (S.sup.-1)* from memory, and minimizing the total energy in trace of matrix product

Energy minimization in surface multiple attenuation

A discrete, minimally-equipped standard seismic calibration system is permanently installed over a subsurface reservoir structure that contains fluids of economic interest. Changes in the fluid content as a function of long-term time lapse may introduce changes in the acoustical characteristics of the reservoir rock layers, producing a corresponding change in the seismic signature recorded by the calibration system. The difference between two signatures over a selected time epoch defines a time-lapse calibration signature. The time lapse calibration signature can be applied to reduce the results of different conventional seismic data-acquisition systems of different vintages and technologies to a common standard.

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Houston, TX, United States of America

William Henry Dragoset, Jr