Abstract: Methods for efficiently acquiring full-azimuth towed streamer survey data are described. The methods use multiple vessels to perform coil shooting.

Abstract: Methods and systems for efficiently acquiring towed streamer marine seismic data are described. One method and system comprises positioning a plurality of source-only tow vessels and one or more source-streamer tow vessels to acquire a wide- and/or full-azimuth seismic survey without need for the spread to repeat a path once traversed. Another method and system allows surveying a sub-sea geologic feature using a marine seismic spread, the spread smartly negotiating at least one turn during the surveying, and shooting and recording during the turn. This abstract is provided to comply with the rules requiring an abstract, allowing 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: The presently disclosed technique includes a method for geophysical survey having at least one source and one receiver, wherein the survey has two sets of survey locations within the survey area, one set of survey locations for the source(s) and the other set of survey locations for the receiver(s), wherein the survey locations in one set are randomized.

Abstract: Methods for efficiently acquiring full-azimuth towed streamer survey data are described. The methods use multiple vessels to perform coil shooting.

Abstract: The presently disclosed technique includes a method for use in a marine survey comprising randomizing the distribution of receivers and sources during a coil shoot acquisition. The randomizing can be implemented in a number of ways. For example, in one embodiment, randomizing the distribution includes randomizing the positions of the circle centers defining the sail lines. This may be implemented by, for example, distributing the same number of circle centers as would be used in a non-random sampling in a uniform random distribution. In another embodiment, randomizing the distribution includes permitting the streamers in which the receivers are allowed to drift while controlling crossline streamer separation. Other embodiments may combine these approaches or utilize still other approaches.

Abstract: Methods to attenuating strong marine seismic noises using singular value decomposition, determining noisiest traces and estimating noise components only from these traces, iteratively estimating the noise and protecting signal behind the noise. 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 technique for acquiring wide azimuth seismic data using simultaneous shooting is presented in which a plurality of seismic sources are positioned to achieve a desired crossline sampling as a function of the number of passes. This is accomplished by “interleaving” sources as deployed in the spread, as positioned in multiple passes, or some combination of these things, to achieve an effective shotline interval during acquisition or an effective crossline sampling less than their crossline source separation.

Abstract: A method for determining a sail plan for a towed-array marine seismic survey includes: dividing a survey area into a regular grid of tiles; and identifying a subset of the tiles as nodes around which continuously curved sail lines are defined. The nodes define regular pattern further including: a first subpattern of nodes; and a second subpattern of nodes offset from the first subpattern. A method for conducting a towed array marine survey includes: traversing a plurality of continuously curved sail lines across a survey area, each sail line being relative to a node; and acquiring seismic data while traversing the continuously curved sail lines. The set of nodes defining a regular pattern further including: a first subpattern of nodes; and a second subpattern of nodes offset from the first subpattern.

Abstract: A technique for use in marine seismic surveying includes a method and an apparatus. In one aspect, the method includes towing a seismic spread including a source multiple streamers on a generally curved advancing path, the streamers being actively steered. The source is fired and data is acquired on the curve. In other aspects, the method is performed with only a single vessel or the generally curved advancing path is a sincurve advancing path. The method may include a dual circular shoot in another aspect. And, in yet another aspect, the invention includes an apparatus comprised of a computing apparatus on board a tow vessel receiving positioning data from the marine seismic streamers. It is also programmed to: sail the tow vessel in a generally curved advancing path and actively steer the marine seismic streamers through the generally curved advancing path.

Abstract: A method for acquiring seismic data. The method may include towing one or more seismic streamers in the water, towing a first air gun array and a second air gun array in the water at a first depth, and towing a third air gun array and a fourth air gun array in the water at a second depth greater than the first depth. While towing the air gun arrays, the first and second air gun arrays and the third and fourth air gun arrays may be separated by a cross line distance that depends on a separation between the seismic streamers. The method may also include firing seismic energy, by the first, second, third and fourth air gun arrays, through the water into the earth. After firing the seismic energy, the method may record seismic signals reflected from strata in the earth beneath the water.

Abstract: A method for determining a sail plan for a towed-array marine seismic survey, includes: dividing a survey area into a regular grid of tiles; and identifying a subset of the tiles as nodes around which continuously curved sail lines are defined. The nodes define regular pattern further including: a first subpattern of nodes; and a second subpattern of nodes offset from the first subpattern. In alternative aspects, a computer-readable program storage medium may be encoded with instructions that, when executed by a processor, perform the method, or a computing apparatus may be programmed to perform the method. A method for conducting a towed array marine survey includes: traversing a plurality of continuously curved sail lines across a survey area, each sail line being relative to a node; and acquiring seismic data while traversing the continuously curved sail lines.

Abstract: Methods and systems for survey designs are disclosed. In one embodiment, a method of towing an array of marine streamers is disclosed, wherein: the array includes a plurality of receivers, the array includes a plurality of steering devices, and the array is towed along a first portion of a coil sail path; steering the array of marine streamers along two or more depths; and steering the array of marine streamers to a slant angle while maintaining the array of marine streamers at their respective two or more depths.

Abstract: Methods to attenuating strong marine seismic noises using singular value decomposition, determining noisiest traces and estimating noise components only from these traces, iteratively estimating the noise and protecting signal behind the noise. 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 for acquiring seismic data. The method may include towing one or more seismic streamers in the water, towing a first air gun array and a second air gun array in the water at a first depth, and towing a third air gun array and a fourth air gun array in the water at a second depth greater than the first depth. While towing the air gun arrays, the first and second air gun arrays and the third and fourth air gun arrays may be separated by a cross line distance that depends on a separation between the seismic streamers. The method may also include firing seismic energy, by the first, second, third and fourth air gun arrays, through the water into the earth. After firing the seismic energy, the method may record seismic signals reflected from strata in the earth beneath the water.

Abstract: A technique for acquiring wide azimuth seismic data using simultaneous shooting is presented in which a plurality of seismic sources are positioned to achieve a desired crossline sampling as a function of the number of passes. This is accomplished by “interleaving” sources as deployed in the spread, as positioned in multiple passes, or some combination of these things, to achieve an effective shotline interval during acquisition or an effective crossline sampling less than their crossline source separation.

Abstract: The presently disclosed technique includes a method for use in a marine survey comprising randomizing the distribution of receivers and sources during a coil shoot acquisition. The randomizing can be implemented in a number of ways. For example, in one embodiment, randomizing the distribution includes randomizing the positions of the circle centers defining the sail lines. This may be implemented by, for example, distributing the same number of circle centers as would be used in a non-random sampling in a uniform random distribution. In another embodiment, randomizing the distribution includes permitting the streamers in which the receivers are allowed to drift while controlling crossline streamer separation. Other embodiments may combine these approaches or utilize still other approaches.

Abstract: The presently disclosed technique includes a method for geophysical survey having at least one source and one receiver, wherein the survey has two sets of survey locations within the survey area, one set of survey locations for the source(s) and the other set of survey locations for the receiver(s), wherein the survey locations in one set are randomized.

Abstract: A method and apparatus for acquiring seismic signals from beneath a salt region in the earth. In one embodiment, the method includes tuning an air gun array to a first bubble oscillation; towing the air gun array in the water at a depth of at least 10 meters, in which the air gun array has a total volume in a range of about 6780 cubic inches to about 10,170 cubic inches; directing acoustic signals with the air gun array down through the water into the earth beneath the salt region; towing one or more seismic streamers in the water at one or more depths, in which at least one of the depths is at least 10 meters, in which each streamer comprises a plurality of hydrophones disposed therealong; and recording with the hydrophones seismic signals reflected from strata in the earth beneath the salt region.

Abstract: A method and apparatus for acquiring seismic data. In one embodiment, the method includes: moving a first air gun array in the water at a first depth and a second air gun array in the water at a second depth greater than the first depth, in which the total volume of the first air gun array is less than the total volume of the second air gun array, in which the first air gun array is separated from the second air gun array by a distance substantially equal to a shot point interval, firing seismic energy through the first and second air gun arrays through the water into the earth, and recording seismic signals reflected from strata in the earth beneath the water.

Abstract: A technique facilitates the reduction of seismic source signature variation during a seismic survey. The technique involves estimating an azimuth angle and/or a departure angle for one or more seismic source elements. The angles are used to determine adjustments, such as seismic source depth adjustments, able to reduce seismic source signature variation. The adjustments can be made prior to firing the one or more seismic source elements.