Abstract: An apparatus for correcting for deviation of an ambient magnetic field direction from a reference direction in a marine environment includes: an instrument assembly vessel configured to move through the marine environment; an inertial reference direction device disposed on the instrument assembly vessel and configured to measure a deviation of an aiming direction of the instrument assembly vessel from the reference direction; a reference magnetic compass disposed on the instrument assembly vessel and configured to measure a direction of the ambient magnetic field direction with respect to the aiming direction of the instrument assembly vessel and to transmit the measured direction; and a processor configured to receive the measured deviation and the measured direction and to calculate the deviation of the ambient magnetic field direction from the reference direction using the received measured deviation and direction.

Abstract: The illumination/imaging of a theorized target horizon that is below a theorized velocity contrast horizon where the velocity contrast horizon may represent the bottom of a salt dome by assessing the path of seismic energy for critical angle reflection/refraction and tabulates the successful paths and unsuccessful paths. For some subsurface locations, seismic energy will not reach the surface above the velocity contrast due to the shapes of the velocity contrast horizon and target horizon and the velocity model through which the studied waves propagate. Displays may be prepared and used for understanding illumination/imaging of the geology for drilling, reacquisition, and reprocessing to elicit information about subsurface geology that may have been overlooked or ignored. Future surveys avoid expensive surveying which cannot obtain useful seismic data as determined by the velocity contrast for the target locations due to the shapes of the horizons and the velocity model.

Abstract: The invention relates to methods and equipment for acquiring and processing marine seismic data are disclosed that correct source movement during inversion. By correcting source movement during inversion, multiple data sets may be acquired independently during overlapping time periods thus reducing the number of sweeps required, generating greater amounts of data, and simplifying data processing.

Abstract: Computer-implemented method for determining optimal sampling grid during seismic data reconstruction includes: a) constructing an optimization model, via a computing processor, given by minu?Su?1 s.t. ?Ru?b?2?? wherein S is a discrete transform matrix, b is seismic data on an observed grid, u is seismic data on a reconstruction grid, and matrix R is a sampling operator; b) defining mutual coherence as ? ? C S ? m ( log ? ? n ) 6 , wherein C is a constant, S is a cardinality of Su, m is proportional to number of seismic traces on the observed grid, and n is proportional to number of seismic traces on the reconstruction grid; c) deriving a mutual coherence proxy, wherein the mutual coherence proxy is a proxy for mutual coherence when S is over-complete and wherein the mutual coherence proxy is exactly the mutual coherence when S is a Fourier transform; and d) determining a sample grid r*=arg minr ?(r).

Abstract: The invention relates to seismic surveying where complex geologies are likely to create data that is confusing or ambiguous for a conventional matrix of acquisition source points and receiver locations. With some understanding of the geological substructure, the acquisition source points and receiver locations that optimize the imaging may be found by using a reciprocal two-way wave equation propagation method coupled with the best geologic model available. With this, the acquisition source points and receiver locations that optimize the imaging may be used in seismic survey to better resolve the substructure and avoid the inclusion of data that obscures understanding of the substructure.

Abstract: The invention relates to a seismic acquisition process where the streamers are intentionally directed to follow an oscillating sweep pattern behind a tow vessel to counteract the effect of the large gaps between the streamers while acquire a wide sweep of data through each pass over the survey area.

Abstract: The present invention relates to a method for synchronizing continuous seismic survey. In particular, the present invention employs a semaphore scheme for the vibes to autonomously and continuously initiate sweeps, thereby decoupling the vibratory source subsystem from the recording subsystem. By using a continuous recorder and the method of the present invention, the recording trucks and the observers can be eliminated, and the vibratory sources can be initiated more efficiently than conventional systems.

Abstract: The invention relates to processing seismic data that includes signals from at least two sources and typically three or four sources where source separation is necessary for geophysical analysis. Specifically, the present invention is an analytical technique that quickly creates a more accurate source signature delivered by analysis of the source generated data contamination present in the separated data. The technique is to invert a segment of the data using a seed source signature and compute an error that reflects the generated data contamination observed in the separated source data. The source signature is iteratively revised as the segment is continually inverted with the goal of finding the optimal source signature that provides the lowest computed error. The source signature that provides the lowest error is, or is very close to, the true source signature and is then used in the separation process for the entire composite data set.

Abstract: The invention relates to processing seismic data that includes signals from at least two sources and typically three or four sources where source separation is necessary for geophysical analysis. Specifically, the present invention is a process for correcting data prior to inversion where the correction is provided to correct for the filtering effect of the earth. The earth is a non-homogenous seismic propagator that causes distortions of wavelets of seismic energy related to the source and receiver azimuth and offset that makes the identification of source specific data within the composite data harder to identify. Computing an earth response and correcting for the effects of the earth on the wavelets provides for more resolution and more clarity in the resulting data and better geophysical interpretation.

Abstract: The invention is an electric sweep type seismic vibrator source of the type used in seismic prospecting for hydrocarbons. The source uses an engine and generator combination to create electric power for all systems on the source such as driving a frame of linear electric motors that direct a rod or piston to contact the ground in a recurring fashion along with driving the source from location to location through a survey area. Preferably, a foot is arranged on the bottom end of the rod or piston for contact with the ground and by engaging the grid of motors to push down against the ground in a rapid progression, acoustic energy is created and delivered into the ground for geophones to sense and record.

Abstract: The invention relates to an arrangement for seismic streamers used in the acquisition of seismic data in a marine environment where the spacing between each adjacent pair of streamers is not all the same. Some streamer spacings and/or receiver spacings are larger and some are smaller to provide a higher quality wavefield reconstruction when covering a larger total area or for a similar total area of seismic data acquisition while providing a wavefield that is optimally sampled by the receivers so that the wavefield reconstruction is suitable for subsurface imaging needs.

Abstract: Reservoir fractures are visualized using electrically active proppants to carry electric signals throughout the fracture. The electric signals are easily detected at the surface using RF antennae and a three-dimensional image of the fracture is generated.

Abstract: Methods and systems are provided for acquiring seismic data in a marine environment using survey paths following a series of linked curved paths so as to obtain multi-azimuthal data over a sub-surface target. Marine vessels towing multiple seismic streamers may be configured to travel substantially along a series of linked deviated paths or a series of linked curved paths. Sources may be excited to introduce acoustic wave energy in the marine environment and into the subsea region. The acoustic wave energy then reflects and refracts from the subsea region to form reflected and refracted wave energy, which is detected by seismic receivers spaced along the streamers. The detected seismic data is then interpreted to reveal seismic information representative of the surveyed subsea region. Other enhancements include configuring the streamers in a flared configuration, where the lateral spacing increases rearwardly over the length of the seismic streamers.

Abstract: The invention relates to acquiring seismic data in either land or marine environments, but typically marine environments where a pulse-type source is fired in a distinctive composite pulse like a distinctive rumble. In a preferred embodiment, a number of pulse-type seismic sources, sometimes called an array, are fired in a distinctive composite pulse to be able to identify within the returning wavefield the energy resulting from the composite pulse. Firing the pulse-type sources creates an identifiable signature so that two or more marine seismic acquisition systems with source arrays can be acquiring seismic data concurrently and the peak energy delivered into the water will be less, which will reduce the irritation of seismic data acquisition to marine life.

Abstract: Methods and systems are provided for acquiring seismic data in a marine environment using survey paths following a series of linked curved paths so as to obtain multi-azimuthal data over a sub-surface target. Marine vessels towing multiple seismic streamers may be configured to travel substantially along a series of linked deviated paths or a series of linked curved paths. Sources may be excited to introduce acoustic wave energy in the marine environment and into the subsea region. The acoustic wave energy then reflects and refracts from the subsea region to form reflected and refracted wave energy, which is detected by seismic receivers spaced along the streamers. The detected seismic data is then interpreted to reveal seismic information representative of the surveyed subsea region. Other enhancements include configuring the streamers in a flared configuration, where the lateral spacing increases rearwardly over the length of the seismic streamers.

Abstract: This invention relates to a method for evaluating and measuring the geometry of a fracture.

Abstract: Methods of seismic data collection are described that reduce the amount of data required, reduce noise in the data collected and collect more data in areas where data collection is required. This results in a dramatic reduction of datasets required and improves noise reduction in data collected. By reducing the amount of data collected and increasing the noise reduction, a more accurate seismic survey is conducted at a dramatically reduced cost.

Abstract: A method for acquisition of seismic data in a marine environment.

Abstract: The invention relates to delivering seismic energy with rotating eccentrics where the eccentrics are driven at relatively high, but different rotational rates create a heterodyned frequency of seismic energy into the earth. The rotating eccentrics may be rotated in opposite directions to deliver pressure waves or in the same direction to create a shear component to the seismic impulses.

Abstract: The invention relates to a sweep-type vibratory seismic source where a baseplate is put to the ground and a series of impulses are applied through the baseplate into the ground and where the baseplate may periodically de-couple from the ground during the delivery of the impulses. A de-coupling baseplate tends to undertake a very high frequency flexing while high frequency energy is being delivered to the ground. The high frequency flexing may be picked up by the vibrator control system and interpreted as an unintended signal being delivered into the ground. While there are already issues getting high frequency data in the return wave field, allowing the vibrator electronics to alter the actual signal in a manner intended to squelch the high pitched ringing of the baseplate is apt to reduce the high frequency data in the data record. One solution for reducing the de-coupling and the ringing of the baseplate is a dampening pad positioned between the baseplate and the ground.