Abstract: Embodiments are directed to systems and methods (200, 300) that enable spatial variability of surface waves to be accounted for in dispersion correction in seismic data processing. This yields superior surface wave noise mitigation, with reduced likelihood of attenuating signal. Embodiments are operative with spatially inhomogeneous media.

Abstract: The present invention relates to producing a quality control measure for use during data acquisition and/or data processing of, preferably, seismic data. While or after obtaining the data, a surface consistent decomposition of the data is performed. From the surface consistent decomposition, one may compute a decomposed logarithmic spectra, and from the decomposed logarithmic spectra, one may compute one or more residua. An error attribute based on the one or more residua can be formulated, analyzed, and output. The error attribute can be used as a quality control measure or the analysis result can be used to produce a quality control measure.

Abstract: A method for acquiring three-dimensional seismic data for sub-surface geologic features wherein a seismic source array is moved along a survey pattern having a plurality of source lines of unequal lengths that are substantially parallel to each other and intersect a receiver line. The survey pattern can be repeated in an overlapping and interleaved fashion to survey a larger area.

Abstract: Methods and related systems are described relating to processing subsurface sonic and seismic data. The described techniques use anisotropy estimates derived from a walkaway VSP to calibrate elastic properties derived from sonic logs. An empirical relationship between the sonic derived anisotropy parameters is modified until the upscaled elastic properties from the sonic log data best matches the anisotropy parameters measured with the walkway VSP. The result is a set of elastic constants consistent with the walkaway VSP measurements.

Abstract: In at least some embodiments, the system obtains shot gathers for a survey region and migrates the shot gather data with an initial velocity model to obtain angle-domain common image gathers. The system processes the common image gathers to determine depth residuals and corresponding angle-dependent time deviations throughout a seismic survey region. The system solves a set of tomographic equations which employ ray theory to establish a relationship between a travel time deviation and the depth residual of a reflector in the depth-offset ray parameter (z,p) domain. The resulting updates are applied to the velocity model and can be used to re-migrate the shot gather data. The system generates a representation of the survey region that can be displayed to a user.

Abstract: Marine seismic data is acquired with a system of steerable seismic streamers that are intentionally maintained in a flared configuration while the streamers are towed through a body of water.

Abstract: The described invention relates to seismic acquisition means for use in shallow water marine environments, comprising: (a) a vessel (1) having at least one hull (25); (b) one or more shaker (13) and baseplate (12) assemblies affixed to the vessel by two or more rigid supporting elements (11) adapted to be capable of lowering said assemblies from the vessel hull to a shallow water bottom (14) and of raising said assemblies from the shallow water bottom to the hull; and, wherein each of said assemblies comprise one or more vibrator units mounted on a baseplate that is adapted to rest upon the shallow water bottom and to transmit vibratory signals from the vibrator units into said water bottom. The described invention provides a high-amplitude, broadband seismic signal, provides high data-production rates, couples energy directly into the earth and minimizes damage to the water bottom.

Abstract: Method for aligning converted wave seismic reflection data (PS data) with conventional PP seismic reflection data so that both data types may be used to more accurately image the subsurface for hydrocarbon exploration or field development. Amplitude vs. angle (AVA) or amplitude vs. offset (AVO) attributes of PP and PS seismic data are identified and defined, which attributes are theoretically expected to be in phase and optimize seismic resolution in the data. In one embodiment of the invention, such attributes are calculated (310), then the same horizons are identified in a series of PP attributes and in a series of PS attributes, then the second series is aligned with the first at the horizon locations (316, 320), then a time transfer function is generated and applied to the PS mode data (322), and the aligned joint-mode data are inverted (326) using, for example, AVA attributes.

Abstract: Methods and apparatuses are disclosed for replacing the individual receivers used with a seismic interferometry process with an array of seismic receivers and then manipulating the array data in order to measure and modify the typical non-uniform directionality function of the background seismic energy. The non-uniform directionality function is a significant cause of noise with seismic interferometry. Furthermore, the array of receivers may be used to significantly enhance the preferred reflection energy and damp undesirable near surface energy. The directionality function may be modified by using an array of receivers for the virtual source location of seismic interferometry to measure the non-uniform directionality function, generating multiplication factors, and applying the multiplication factors to convert the measured directionality function into a desired directionality function.

Abstract: A marine cable for seismic surveys is described with a plurality of ceramic pressure sensors (901-904) arranged in groups of at least two pressure sensors with a group output being representative of the vertical pressure gradient at the group location, and an inclinometric system including one or more transducers for determining the orientation of the sensors of the group in order to determine their true vertical separation.

Abstract: A paravane for a seismic acquisition system includes a float, a frame suspended from the float, deflectors affixed to the frame, and means for coupling a tow rope to a lead-in functionally extending between a forward end and an aft end of the frame. The paravane includes means for selectively changing an effective position along the lead-in of the means for coupling the tow cable.

Abstract: A method for generating seismic energy for subsurface surveying include operating a first seismic vibrator above an area of the subsurface to be surveyed and operating at least a second seismic vibrator above the area substantially contemporaneously with the operating the first seismic vibrator. The first and the second vibrators each have a different selected frequency response. The first and second vibrators each is operated by a same direct sequence spread spectrum signal, wherein a different number of modulation operations for each logical value in the direct sequence spread spectrum signal is selected for each vibrator.

Abstract: A method of modeling seismic wave-field data in order to suppress near-surface and sub-surface related multiple reflection signals is provided. The reflection signals include main primary reflection signals, main random noise signals, main multiple reflection signals, residual primary reflection signals, residual random noise signals, and residual multiple reflection signals. Main random noise signals are separated from the reflection signals using a frequency-wavenumber domain method to provide data having suppressed main random noise. Main primary reflection signals are separated from the data having suppressed main random noise using frequency-wavenumber filtering and weighted median filtering to provide data having suppressed main random noise and main primary reflections. Multiple reflection signals are modeled using parabolic path summation on the data having suppressed main random noise and main primary reflections.

Abstract: This is a method of separating simultaneous sources that uses an inversion-type approach. Each source will preferably activated at a random time with respect to the others. These random delays tend to make the interference between sources incoherent while the reflections create coherent events within a series of shots. The shot separation is performed via a numerical inversion process that utilizes the sweeps for each shot, the start times of each shot, and the coherence of reflection events between nearby shots. This method will allow seismic surveys to be acquired faster and cheaper.

Abstract: Method for migration of seismic data into datasets having common azimuth angle at the reflection point. A velocity model is selected that prescribes subsurface P and/or S wave velocities including any required anisotropy parameters. (41) For shot locations on a surface grid, rays are traced on to a 3D grid of points in a target region of the subsurface. (42) At least the travel times of the rays and their dip angles at each subsurface point are stored in computer memory as they are computed. (43) Using the stored ray maps, the seismic data are migrated into seismic image volumes, each volume being characterized by at least an azimuthal angle bin, the azimuthal angles being computed from said ray dip angle information (44).

Abstract: In some aspects of the disclosure, a method for creating three-dimensional images of non-linear properties and the compressional to shear velocity ratio in a region remote from a borehole using a conveyed logging tool is disclosed.

Abstract: Seismic data recorded in a marine streamer are obtained, sorted as a common receiver gather. A complex Laplace frequency parameter is used to transform the seismic data from a space-time domain to a spectral domain. An iterative conjugate gradient scheme, using a physically-based preconditioner, is applied to the transformed seismic data, to provide a least squares solution to a normal set of equations for a source deghosting system of equations. The solution is inverse-transformed back to a space-time domain to provide source deghosted seismic data, which is useful for imaging the earth's subsurface.

Abstract: Systems and methods for modeling a three-dimensional (3D) geological structure to improve maximum continuity interpolation. An integration method describes local anisotropic effects and introduces interpolation techniques to perform the interpolation between two points of interest along a direction of maximum continuity and across fault surfaces.

Abstract: Seismic data recorded in a marine streamer are obtained, with the seismic data being representative of characteristics of subsurface earth formations and acquired by deployment of a plurality of seismic receivers overlying an area of the subsurface earth formations to be evaluated, the seismic receivers generating at least one of an electrical and optical signal in response to seismic energy. A complex Laplace frequency parameter is used to transform the seismic data from a space-time domain to a spectral domain. An iterative conjugate gradient scheme, using a physically-based preconditioner, is applied to the transformed seismic data, to provide a least squares solution to a normal set of equations for a deghosting system of equations. The solution is inverse-transformed back to a space-time domain to provide deghosted seismic data, which is useful for imaging the earth's subsurface.

Abstract: In some embodiments, apparatus and systems, as well as methods, may operate to select an amount of imaging coverage associated with a substantially tubular object and a rotary scanner coupled to a telemetry system. Determining circumferential and longitudinal scan sampling intervals to provide substantially full coverage of the substantially tubular object may be included. Waveform sampling and transducer driving waveform parameters may also be determined according to an available data transmission bandwidth associated with the telemetry system.