Abstract: A seismic source array includes a first source and a second source. The first source has a first spectral output and the second source has a second spectral output different than the first spectral output. The first source has a first total volume different than a second total volume of the second source.

Abstract: Methods and apparatuses for acquiring marine seismic data to generate images or determine properties of an interior section of the Earth using simultaneous marine vibrator sweeps and methods for processing the acquired seismic data. Phase of sweeps produced by the marine vibrator(s) are controlled to provide for removal of crosstalk. The phases between marine vibrator sweeps may be random or controlled to have a predetermined/desired phase difference. The predetermined phases may be determined to minimize the crosstalk between sweeps based on known seismic velocity of the survey area.

Abstract: The technologies described herein include systems and methods for performing a first seismic survey and performing a second seismic survey after a predetermined amount of time has lapsed between the first seismic survey and the second seismic survey. The shot times and the shot positions of the second seismic survey may be substantially the same as the shot times and the shot positions of the first seismic survey. After performing the seismic surveys, seismic data generated by the first seismic survey may be processed to generate a first image, and seismic data generated by the second seismic survey may be processed to generate a second image. After generating the first and second images, a difference between the first image and the second image may be computed to generate a time lapse difference image.

Abstract: A method includes receiving a representation of a volume acceleration of a seismic vibrator. The method includes determining a signature of the seismic vibrator based at least in part on the representation of the volume acceleration.

Abstract: A method includes receiving data representing measurements acquired by seismic sensors in response to energy that is produced by shots of a seismic source. The energy that is produced by the seismic source for each shot includes a plurality of discrete frequencies of discrete frequency bands that are within a frequency range of interest and are separated by at least one excluded frequency or frequency band. The data may be processed to determine at least one characteristic of a geologic structure.

Abstract: A technique includes towing at least one seismic source in connection with a survey of a structure; and operating the seismic source(s) to fire shots, where each shot is associated with a frequency sweep. The technique includes varying phases of the frequency sweeps from shot to shot according to a predetermined phase sequence to allow noise in an energy sensed by seismic sensors to be attenuated.

Abstract: A marine survey acquisition system. The system may include a vessel for towing a marine survey spread. The marine survey spread may include streamers, marine vibrators and a cable. The cable may be coupled to a respective streamer from among the streamers and one of the marine vibrators. The cable may power the respective streamer and the one of the marine vibrators. The one of the marine vibrators may emit energy at a high frequency range.

Abstract: The technologies described herein include systems and methods for performing a first seismic survey and performing a second seismic survey after a predetermined amount of time has lapsed between the first seismic survey and the second seismic survey. The shot times and the shot positions of the second seismic survey may be substantially the same as the shot times and the shot positions of the first seismic survey. After performing the seismic surveys, seismic data generated by the first seismic survey may be processed to generate a first image, and seismic data generated by the second seismic survey may be processed to generate a second image. After generating the first and second images, a difference between the first image and the second image may be computed to generate a time lapse difference image.

Abstract: A method for selecting parameters of a seismic source array comprising a plurality of source elements each having a notional source spectrum is described, the method comprising calculating a ghost response function of the array; calculating directivity effects of the array; and adjusting the parameters of the array such that the directivity effects of the array are compensated by the ghost response to minimize angular variation of a far field response in a predetermined frequency range. A method for determining a phase center of a seismic source array is also related, the method comprising calculating a far field spectrum of the array at predetermined spherical angles, and minimizing the phase difference between the farfield spectra within a predetermined frequency range by adjusting a vertical reference position from which the spherical angles are defined.

Abstract: A technique facilitates obtaining seismic data in a marine environment. An array of acoustic sources is deployed in a marine environment. The array can be utilized for creating acoustic pulses that facilitate the collection of data on subsea structures. The methodology enables optimization of acoustic source array performance to improve the collection of useful data during a seismic survey.

Abstract: A seismic source array includes a first source and a second source. The first source has a first spectral output and the second source has a second spectral output different than the first spectral output. The first source has a first total volume different than a second total volume of the second source.

Abstract: A method for selecting parameters of a seismic source array comprising a plurality of source elements each having a notional source spectrum is described, the method comprising calculating a ghost response function of the array; calculating directivity effects of the array; and adjusting the parameters of the array such that the directivity effects of the array are compensated by the ghost response to minimize angular variation of a far field response in a predetermined frequency range. A method for determining a phase center of a seismic source array is also related, the method comprising calculating a far field spectrum of the array at predetermined spherical angles, and minimizing the phase difference between the farfield spectra within a predetermined frequency range by adjusting a vertical reference position from which the spherical angles are defined.

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 marine cable for seismic surveys is described with a plurality of ceramic pressure sensors 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 method for selecting parameters of a seismic source array comprising a plurality of source elements each having a notional source spectrum is described, the method comprising calculating a ghost response function of the array; calculating directivity effects of the array; and adjusting the parameters of the array such that the directivity effects of the array are compensated by the ghost response to minimize angular variation of a far field response in a predetermined frequency range. A method for determining a phase center of a seismic source array is also related, the method comprising calculating a far field spectrum of the array at predetermined spherical angles, and minimizing the phase difference between the farfield spectra within a predetermined frequency range by adjusting a vertical reference position from which the spherical angles are defined.

Abstract: A method for correcting marine seismic data is described in which a measured surface elevation relative to a reference surface of an array of source units is used to compensate for variations in the height and/or shape of a sea surface. Various embodiments correct for the elevation of the array as a whole, differences in the elevation of source units within the array, and scattering from the sea surface which arises due to the sea surface not being flat.

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.