Abstract: Systems and methods for determining position of one or more seismic streamers are disclosed. One system embodiment includes a seismic streamer towed by a towing vessel at a first depth; at least one positioning streamer towed by the towing vessel at a second depth different than the first depth; and an acoustic ranging system between the seismic and positioning streamers 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. 37 CFR 1.72(b).

Abstract: A method and apparatus for correcting an input seismic trace. The method includes receiving the input seismic trace and creating a t by Q gather using the input seismic trace, where t represents traveltime, Q represents absorption parameter, and the t by Q gather has traveltime as the vertical axis and a ratio of t and Q as the horizontal axis. The ratio of t and Q is referred to as R. The method further includes applying an interpolation algorithm to the t by Q gather to derive a corrected input seismic trace.

Abstract: A method and apparatus for a method for generating an estimated value of absorption parameter Q(t). In one embodiment, the method includes receiving an input seismic trace, applying a time variant Fourier transform to the input seismic trace to generate a time variant amplitude spectrum of the input seismic trace, dividing the natural logarithm of the time variant amplitude spectrum by ??f, and performing a power series approximation to the result with an index starting from one to generate an estimated value of R(t). R(t) is a ratio between traveltime t and the absorption parameter Q(t). The method further includes dividing t by R(t) to generate the estimated value of the absorption parameter Q(t).

Abstract: A method and apparatus for predicting a plurality of surface multiples for a plurality of traces in a record of seismic data. In one embodiment, the method includes providing a plurality of target traces at a nominal offset and a nominal azimuth; selecting a plurality of pairs of input traces, wherein the midpoints of the input traces in each pair are separated by half the nominal offset and the azimuth of a line connecting the midpoints of the input traces in each pair is equal to the nominal azimuth; convolving the selected pairs of input traces to generate a plurality of convolutions; and applying a three dimensional operator to the convolutions.

Abstract: Methods and apparatus are provided for controlled source electromagnetic surveying. In particular, a time-varying electromagnetic signal is transmitted at a first location, and an electromagnetic signal responsive to the transmitted signal is received at a second location, wherein the received signal includes a transient response component and a steady-state component. The received signal is continuously recorded during a predetermined time interval, and data corresponding to the transient response component and the steady-state component are extracted from the received signal. The transient response data and the steady-state response data are jointly inverted to identify a subsurface feature, such as resistivity.

Abstract: Apparatus, systems and methods for connecting two seismic streamers are disclosed that enable two streamers to be towed in a desired arrangement. One apparatus comprises an elongate member having a first portion and a second portion, and an orientation member connected to the elongate member between the first and second portions, the orientation member functioning, when the streamers are connected by the apparatus and towed, to maintain orientation of the streamers. 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: Method for determining acceptability of sensor locations used to perform a seismic survey. In one implementation, the method includes obtaining a first set of reference data, generating a first output trace from a second set of reference data estimated from the first set of reference data at a plurality of planned sensor locations, generating a second output trace from a third set of reference data estimated at a plurality of actual sensor locations and comparing the second output trace with the first output trace to determine whether the variation between the second output trace and the first output trace is less than a predetermined value.

Abstract: Method for processing seismic data to correct for errors caused by variation in water conditions.

Abstract: The technologies described herein include systems and methods for encoding/decoding seismic sources and responses, generating and using of source-side derivatives while also generating and using the conventional source response. Sources in an array may be encoded such that activation of each source in the array constitutes a single spike in a sequence orthogonal to another sequence emitted by another source. The responses to these different sources that are in close spatial proximity can be decoded and separated. Source-side derivatives may be calculated and utilized in various applications in combination with the monopole response from the source location, including source-side deghosting, spatial (horizontal and vertical) interpolation and imaging.

Abstract: The present invention provides a method and apparatus for wave field separation. The method includes accessing a marine seismic data set acquired by a plurality of receivers deployed at a first plurality of depths in response to a plurality of acoustic signals provided by a plurality of seismic sources deployed at a second plurality of depths and forming at least one de-ghosted marine seismic data set based upon the plurality of seismic data sets.

Abstract: Implementations of various technologies for processing seismic data. In one implementation, the seismic data may be processed by creating a fictitious source-receiver line connecting a source with a receiver location of interest, projecting one or more receiver locations adjacent the receiver location of interest onto the fictitious source-receiver line and decomposing seismic data on the receiver locations disposed on the fictitious source-receiver line into up-going wavefields and down-going wavefields.

Abstract: A method of processing geophysical data including determining the azimuth of a mirror symmetry plane within the earth from the geophysical data having sets of geophysical data acquired with different source-receiver azimuths. The data are processed to determine attributes of the geophysical data that are azimuth-dependent. One azimuth-dependent attribute of the geophysical data is selected, and a value of the source-receiver azimuth about which the selected attribute exhibits mirror symmetry is determined. This locates a mirror symmetry plane within the earth. The value of the source-receiver azimuth may be determined by generating an objective function indicative of the difference between the actual value of an attribute at one azimuth and the value predicted for that attribute at that azimuth using a trial estimate of the azimuth of a mirror symmetry plane, and finding the azimuth of a mirror symmetry plane that minimizes the objective function.

Abstract: A deflector device (22) for use with a tow lie between a towing vessel (10) and a tow (16) in water behind the vessel, the device comprising a principal wing-shaped body (28) shaped to produce in use a sideways force which urges the tow line (16) laterally with respect to the direction of movement of the towing vessel, a boom (32) extending rearwardly from the principal wing-shaped body (28), and an auxiliary wing-shaped body (52), smaller than the principal wing-shaped body (28), secured to the end of the boom (32) remote from the principal wing-shaped body (28) and shaped so as to produce in use a sideways force in generally the opposite direction to that produced by the principal wing-shaped body (28).

Abstract: A method includes recording a first set of data using a first type of sensor; recording a second set of data using a second type of sensor, the first and second sets of data being contemporaneously acquired by co-located sensors; and removing noise from the first data set using the second data set. An apparatus includes a survey vessel towing an array of towed streamers including a plurality of paired, co-located sensors densely distributed along the streamers. A first one of each sensor pair is of a first type and a second one of each sensor pair is of a second type. A computing apparatus records a first set of data acquire by the first type of sensor and a second data set acquire by the second type of sensor. The computing apparatus then removes noise from the first data set using the second data set.

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: The present invention provides a method and apparatus for positioning a center of a seismic source. The method includes determining a desired center-of-source of the seismic source and selecting one of a first and a second plurality of guns to form the seismic source based upon the desired center-of-source, a center-of-source of the first plurality being different than a center-of-source of the second plurality.

Abstract: A method of processing seismic data including convolving at least first and second seismic data traces or respective portions of at least first and second seismic data traces to forma composite trace. The travel time of an event may then be determined in the composite trace. This provides an improved method compared to the prior art technique of picking the travel time of an event individually in each one of a number of seismic data traces and averaging the individual picked travel times.

Abstract: Systems and methods for positioning seismic streamers are disclosed that enable two or more streamers to be positioned in over/under configuration. One system comprises first and second pluralities of remotely controllable birds mounted on or inline in first and second streamers, the birds functioning to control position of the streamers relative to each other, to another pair of streamers, or to some reference. 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. 37 CFR 1.72(b).

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: 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.