Abstract: A method is provided of processing multi-component seismic data acquired by emitting multi-component seismic energy at a source location and acquiring seismic data at a multi-component seismic receiver located at a greater depth than the source location. The seismic data are decomposed into up-going constituents and down-going constituents. A de-signature and de-multiple operator is calculated from the down-going constituents of the seismic data and from properties of the medium surrounding the receiver.

Abstract: Information about coupling of a seismic receiver is obtained from a power spectrum for a record acquired at a seismic receiver. In one method, the power spectrum for the record is compared with a reference power spectrum, which may be known a priori or which may be determined from the power spectra of records acquired by a group of receivers. In an alternative method, one receiver of a group of receivers is designated as a reference receiver, and the power spectra of records acquired by other receivers in the group are compared with a power spectrum for the reference receiver. The obtained information about the coupling of a receiver may be used to determine a coupling correction operator for the receiver, and this operator can be applied to seismic data acquired by the receiver to correct for the effects of imperfect coupling of the receiver.

Abstract: The present invention provides an apparatus and a method for reducing wing-tip vortex energy during seismic exploration. The apparatus includes a vortex concentrator of deployed proximate a tip of a hydrofoil and a vortex reducing device deployed proximate the vortex concentrator.

Abstract: The present invention provides a method for harmonic noise attenuation in correlated sweep data in seismic exploration. The method includes forming a plurality of correlation data subsets using a plurality of sweep data sets and a correlation reference sequence. The method further includes estimating a noise level in a correlation data set using the correlation data subsets and subtracting the estimated noise level from the correlation data set.

Abstract: This invention relates in general to vibroseis and, more specifically, but not by way of limitation, to the enhancement and/or signal strength optimization of low frequency content of seismic signals for use in surveying boreholes and/or subsurface earth formations. In embodiments of the present invention, physical properties of a seismic vibrator may be analyzed and used to provide for determination of a driving force necessary to drive a reaction mass to produce a sweep signal with enhanced low frequency content for injection into the ground for vibroseis. In certain aspects, the physical properties may be considered independent of any geophysical properties related to operation of the seismic vibrator.

Abstract: Methods and apparatus for acquiring seismic data using a seabed seismic data cable positioned on a seabed are described, one method including deploying a seabed seismic cable, the cable comprising two or more active sections separated by at least one jumper section; and acquiring seabed seismic data using the seabed seismic cable. Certain methods include analyzing spacing needed between active sensor units in the active sections prior to deploying the seabed seismic cable, and selecting a length of the jumper section based on the analysis. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: A method of controlling a streamer positioning device (18) configured to be attached to a marine seismic streamer (12) and towed by seismic survey vessel (10) and having a wing and a wing motor for changing the orientation of the wing. The method includes the steps of: obtaining an estimated velocity of the streamer positioning device, calculating a desired change in the orientation of the wing using the estimated velocity of the streamer positioning device, and actuating the wing motor to produce the desired change in the orientation of the wing. The invention also involves an apparatus for controlling a streamer positioning device including means for obtaining an estimated velocity of the streamer positioning device, means for calculating a desired change in the orientation of the wing using the estimated velocity of the streamer positioning device, and means for actuating the wing motor to produce the desired change in the orientation of the wing.

Abstract: A method of processing seismic data comprises identifying the value of a first parameter associated with an event in a first set of seismic data. The value of a second parameter associated with a corresponding event in a second sent of seismic data is then obtained using at least one look-up table. The first parameter may be PP travel time with the first data set being a raw PP data set, and the second parameter may be PS travel time with the second data set being a raw PS data set or reflection depth. The invention makes it possible to identify pairs of corresponding PP and PS events in raw data traces. The look-up table(s) are obtained using an assumed model for the velocity of propagation of acoustic energy within the earth. The results of the method may be used in quality control, or to correct the velocity model.

Abstract: Interpretation of a shot gather and a stack of seismic data. In one implementation, the shot gather is sorted into a first component shot gather, a second component shot gather and a third component shot gather. The first component shot gather is represented as a first subimage, the second component shot gather is represented as a second subimage, and the third component is represented as a third subimage. The first subimage is then merged with the second subimage and the third subimage to create a false color image. The shot gather of seismic traces may then be interpreted based on the false color image. The first component may by an x component, the second component may be a y component and the third component may be a z component. The first subimage may be a red or cyan subimage, the second subimage may be a green or yellow subimage and the third subimage may be a blue or magenta subimage.

Abstract: Methods and systems for determining position of one or more portions of a seismic streamer, which portions may be seismic receivers, are disclosed. One method includes measuring one or more characteristics of one or more steering devices positioned at known distances along a marine seismic streamer; using the measured characteristic to calculate a force on at least a portion of the streamer exerted by one or more steering devices from the characteristics; and using the calculated force to estimate position of at least a portion of the streamer. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: A mehtod of determinig an integral of a function over an n-dimensional intergratio domain from the values of the function at a plurality of discrete data points within the integration domain, comprises partitioning the integration domain into a plurality of k-dimensional simplexes, where k<=n. The function is integrated over each simplex, and the results are summed. The method may be applied in the processing of geophysical data such as, for example, seismic data, where the function is a function of at least the geophysical data. The processed data may then be used to obtain information about the physical properties of the earth's interior.

Abstract: Method and apparatus for predicting surface multiples, which includes (a) selecting a target subsurface line (SSL); (b) selecting an input SSL within an aperture of the target SSL; (c) selecting a point on a line twice the distance between the input SSL and the target SSL, the point corresponding to a potential downward reflection point of the surface multiples for a trace; (d) generating a potential surface multiple for the trace corresponding to the point; (e) repeating steps (c) through (d) for each point on the line to generate an inline of potential surface multiples corresponding to each point on the line; (f) repeating steps (b) through (e) for each input SSL within the aperture of the target SSL to generate potential surface multiples for the trace corresponding to each input SSL within the aperture; and (g) adding the potential surface multiples to generate a surface multiple for the trace.

Abstract: 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.

Abstract: A method of controlling a streamer positioning device (18) configured to be attached to a marine seismic streamer (12) and towed by seismic survey vessel (10) and having a wing and a wing motor for changing the orientation of the wing. The method includes the steps of: obtaining an estimated velocity of the streamer positioning device, calculating a desired change in the orientation of the wing using the estimated velocity of the streamer positioning device, and actuating the wing motor to produce the desired change in the orientation of the wing. The invention also involves an apparatus for controlling a streamer positioning device including means for obtaining an estimated velocity of the streamer positioning device, means for calculating a desired change in the orientation of the wing using the estimated velocity of the streamer positioning device, and means for actuating the wing motor to produce the desired change in the orientation of the wing.

Abstract: A deflector for offsetting a streamer being towed by its lead-in by a seismic survey vessel comprises a wing-shaped body which is coupled to the lead-in and shaped to produce a sideways force which urges the lead-in laterally with respect to the direction of movement of the vessel. A boom extends rearwardly from the wing-shaped body, and forms part of an arrangement by which the angle of the wing-shaped body in the water, and therefore the sideways force produced by it, can be varied. The upper end of the wing-shaped body is directly connected to the underside of an elongate float.

Abstract: The invention concerns a method for retrieving local near-surface material information including the steps of:—providing a group of receivers comprising at least one buried receiver and at least one surface receiver positioned either at or very near the Earth surface;—recording a seismic wavefield;—estimating a propagator from said recorded seismic wavefield;—inverting said propagator; and—retrieving said near-surface material information.

Abstract: A method of filtering seismic signals is described using the steps of obtaining the seismic signals generated by activating a seismic source and recording signals emanating from the source at one or more receivers; defining a source signature deconvolution filter to filter the seismic signal, wherein the filter is scaled by a frequency-dependent term based on an estimate of the signal-to-noise (S/N) based on the spectral power of a signal common to a suite of angle-dependent far-field signatures normalized by the total spectral power of the signatures within the angular suite and performing a source signature deconvolution using the source signature deconvolution filter.

Abstract: A method of processing seismic data comprises transforming seismic data which contain coherent noise to a domain in which at least some of the coherent noise is transformed to incoherent noise. The seismic data are then filtered in the new domain, to remove or attenuate the incoherent noise. If desired, the filtered data may subsequently be transformed back to the domain in which the data were acquired. The filtering process may be carried out using a multichannel interference canceller. A seismic data trace to be filtered is input to the principal channel of the interference canceller, and one or more other seismic data traces are input to the interference canceller as reference traces. Use of seismic data traces as the reference trace(s) avoids the need to determine a noise reference trace.

Abstract: A method of determining at least one parameter of a waveguide (3) from wavefield data acquired from wave propagation in the waveguide including obtaining first and second dispersion curves (9a, 9b, 9c) in the frequency domain from the wavefield data. A frequency interval between the first dispersion curve and the second dispersion curve is found, and this is used in the determination of at least one parameter of the waveguide. The frequency separation ?ƒ(V) between the first and second dispersion curves may be found at a particular value of the phase velocity V, and the thickness h of the waveguide can be found using: ? ? ? f ? ( V ) = c 1 2 ? h ? 1 - c 1 2 V 2 Here, c1 is the velocity of wave propagation in the waveguide. This may be found from the asymptotic velocity values of the dispersion curves.

Abstract: A method of controlling a streamer positioning device configured to be attached to a marine seismic streamer and towed by a seismic survey vessel and having a wing and a wing motor for changing the orientation of the wing. The method includes the steps of: obtaining an estimated velocity of the streamer positioning device, calculating a desired change in the orientation of the wing using the estimated velocity of the streamer positioning device, and actuating the wing motor to produce the desired change in the orientation of the wing. The invention also involves an apparatus for controlling a streamer positioning device including means for obtaining an estimated velocity of the streamer positioning device, means for calculating a desired change in the orientation of the wing using the estimated velocity of the streamer positioning device, and means for actuating the wing motor to produce the desired change in the orientation of the wing.