Abstract: A seismic surveying arrangement comprises a vertical source array (26) having at least two sources (27,28) of seismic energy. The source array (26) is disposed such that a first source (28) is located within a weathered layer (35) of the earth's interior and such that a second source (27) is located within the weathered layer at a greater depth than the first source or within a high velocity layer (8) underlying the weathered layer (35). The surveying arrangement also includes a first horizontal receiver array (29) located in the weathered layer, and means for processing seismic data acquired by the first receiver array. The processing means are able to process the acquired seismic data so as to attenuate seismic events involving reflection of seismic energy at at least one boundary face of the high velocity layer. The seismic surveying arrangement may also comprise a second receiver array (30) disposed at a lower depth than the first receiver array (29).

Abstract: Various technologies for a method for processing seismic data. In one implementation, the method includes cross-correlating seismic traces having midpoint locations, offsets and azimuths within a predetermined range but from different sequences; and selecting a peak on each cross-correlation. Each peak corresponds to a difference in travel times between two seismic traces that were cross-correlated. The method further includes converting the difference in travel times between the two seismic traces to a difference in water velocities between a pair of sequences associated with the two seismic traces at a spatial location.

Abstract: A method for compensating for one or more transmission delays between a multiplexer, a first node and a second node.

Abstract: Method for processing seismic data. In one implementation, the method includes converting a common midpoint (CMP) gather of seismograms into one or more interferogram common midpoint (ICMP) gathers, generating a semblance spectrum for each ICMP gather, stacking the semblance spectrum from each ICMP gather to generate a combined semblance spectrum and deriving a normal moveout (NMO) velocity profile from the combined semblance spectrum.

Abstract: Methods and systems for determining position of seismic sources and receivers are disclosed. Signals received by a first antenna are processed to determine its 3D coordinate position. Signals received by the first antenna and a second antenna are combined and processed to estimate a spatial vector between the first and second antennas. The spatial vector is added to the 3D coordinate position of the first antenna to provide a 3D coordinate position of the second antenna. Using the 3D coordinate position of the second antenna, a 3D coordinate position of a seismic source unit or receiver may be calculated, as well as a vertical correction for reflected seismic signals received by the receiver. This abstract allows a searcher or other reader to quickly ascertain the subject matter of the disclosure. It will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Abstract: A method of matching the impulse response of a hydrophone and the impulse of a geophone accelerometer comprises performing a calculus operation upon the response of one of the hydrophone and the accelerometer. A filter is then derived from the output of the calculus operation and the response of the other of the hydrophone and the accelerometer. The filter may then be used to match seismic data acquired by the one of the hydrophone and the accelerometer to seismic data acquired by the other of the hydrophone and the accelerometer. The calculus operation may comprise differentiating the hydrophone response, or integrating the accelerometer impulse response.

Abstract: A method of processing seismic data that includes including first and second modes of seismic energy where the second mode has been generated by partial mode conversion of the first mode at a boundary face of a layer of the seabed includes the step of cross-correlating a trace acquired at a receiver and including events corresponding to the first mode with a trace acquired at the same receiver and including events corresponding to the second mode. An event in the cross-correlated data that corresponds to partial mode conversion is identified, and the amplitude of this event is normalized, for example relative to the amplitude of the peak in the cross-correlogram at zero time delay. Information about the effects of the static shift produced by the layer and/or about vector infidelity can be arrived from normalized cross-correlograms for receivers in a receiver array.

Abstract: An apparatus and method for processing a record of seismic traces. The method includes receiving the record of seismic traces in a time-offset domain, transforming the record of seismic traces to a tau-p domain, applying a zero offset inverse Q algorithm to the record of seismic traces in the tau-p domain, and transforming the record of seismic traces back to the time-offset domain.

Abstract: A method and apparatus for filtering data acquired at a plurality of discrete data points is described, using the steps of defining a filter having defined filter values at defined filter points at least partially not coincident with the data points and using the defined filter values at the defined filter points to determine filter values at the data points, thereby correcting the filter to have filter values at filter points coinciding with the data points and filtering the data using the corrected filter.

Abstract: The invention relates to processing seismic data that contains both a desired signal and swell noise. The method is applicable to seismic data is in the frequency-space domain method and comprises determining a signal-only prediction filter from the seismic data at a first frequency at which swell noise is not present, and applying the prediction filter to seismic data at a second frequency at which swell noise is present. This attenuates swell noise in the seismic data at the second frequency. In one embodiment, the prediction filter for a frequency fL, the lowest frequency at which swell noise is present, is determined from seismic data at frequency fH+1, where fH is the highest frequency at which swell noise is present. The prediction filter for a frequency fL+1 is determined from seismic data at frequency fH+2, and so on, so that the prediction filter for frequency fH+1 is determined from seismic data at frequency f2H?L+1.

Abstract: The present invention provides a method and apparatus for a segmented antenna system. The method includes determining an orientation of a first antenna, the first antenna including a plurality of segments for transmitting and receiving signals, determining a direction from the first antenna to a second antenna capable or at least one of transmitting and receiving signals, and selecting at least one of the plurality of segments of the first antenna using the determined orientation of the first antenna and the determined direction.

Abstract: Implementations of various techniques for processing seismic data acquired by three or more over/under streamers. In one implementation, the seismic data may be processed by grouping the seismic data into one or more sets of seismic data based on all possible pairs of the three or more over/under streamers, wherein each set of seismic data comprises seismic data that had been acquired by a pair of the three or more over/under streamers, applying a shift and subtract algorithm to the one or more sets of seismic data, and applying a dephase and sum algorithm to the one or more sets of seismic data.

Abstract: The present invention provides a method for analyzing traces collected along a plurality of adjacent sail lines in a marine seismic survey area. The method comprises selecting a plurality of trace groups, at least one trace in each group sharing a common midpoint with at least one trace from another group, determining an initial zero-offset travel time for each trace in the trace groups, and generating a plurality of updated zero-offset travel times and a plurality of time corrections for the trace groups using a pre-selected function of the initial zero-offset travel times.

Abstract: A device including a housing defining a first chamber and a port formed through the housing. A shuttle flange moveably positioned within the first chamber. The shuttle flange moves during a gas-release cycle between i) a closed position blocking the port, and ii) an open position exposing an exit area of the port through which a compressed gas is discharged. A method for generating a seismic pressure pulse in water includes the steps of, confining a compressed gas within a chamber having a port, creating an exit area through the port by moving a shuttle along the length of the port during a gas-release cycle, pre-releasing a charge of the compressed gas through the exit area to create a pre-released bubble, choking the exit area, and producing a primary pressure pulse by releasing a main charge of compressed gas through the exit area.

Abstract: A method for computing a pressure signal gradient. The method includes recording a plurality of pressure signals at least one of a first receiver and a second receiver. The first receiver and the second receiver are disposed within a cluster. The method further includes recording a plurality of pressure signals at the second receiver; computing a calibration filter for removing the difference in distortions between the pressure signals recorded at the first receiver and the pressure signals recorded at the second receiver; and computing the pressure signal gradient between the pressure signals recorded at the first receiver and the pressure signals recorded at the second receiver using the calibration filter.

Abstract: A method and apparatus is provided for determining a propagation time delay. The apparatus includes at least one source adapted to generate a plurality of positioning signals, at least one receiver deployed along a seismic sensing cable, wherein the receiver is adapted to receive the plurality of positioning signals from the at least one source, and a plurality of computed Doppler-shifted positioning signals corresponding to the plurality of positioning signals. The apparatus also includes a signal processing unit adapted to determine a propagation time delay between the source and the receiver using the generated positioning signals, the received positioning signals, and the plurality of computed Doppler shifted positioning signals.

Abstract: A method and apparatus for estimating a porosity and a saturation in a subsurface reservoir. The method includes determining a plurality of mathematical relationships relating a plurality of fundamental physical parameters that govern elastic wave propagation in the subsurface reservoir to the porosity and the saturation in the subsurface reservoir, forward modeling a plurality of seismic attributes using the mathematical relationships to derive a plurality of conditional probability density functions for the seismic attributes, applying a Bayesian inversion to the conditional probability density functions for the seismic attributes to derive a joint probability density function for the porosity and the saturation in the subsurface reservoir, and integrating the joint probability density function for the porosity and the saturation to derive a probability density function for the porosity and a probability density function for the saturation.