Abstract: Methods and apparatus are described for performing a 4D monitor marine seismic survey that repeats a previous survey. A number of sources may be used during the 4D monitor survey that differs from a number of sources that were used during the previous survey. Shot points from the previous survey are repeated by the 4D monitor survey, and additional shot points may be produced during the 4D monitor survey that were not produced during the previous survey. Embodiments enable efficiency and data quality improvements to be captured during 4D survey processes, while preserving repeatability.

Abstract: A method and apparatus for marine surveying includes: towing sources in a wide-tow source geometry; towing streamers that comprise receivers; actuating at least one of the sources to create a signal; and detecting the signal with a first receiver, wherein: at least one of the source separations or the streamer separations is non-uniform, and the sources and the receivers provide a regular sampling grid for the survey area. A system includes a survey plan; sources in a wide-tow source geometry; and streamers comprising receivers, wherein: at least one of the source separations or the streamer separations is non-uniform, and the sail lines, sources, and receivers provide uniform CMP coverage for the survey area. A method includes operating a system in a survey area, the system having a non-uniform configuration with wide-tow source geometry; actuating at least one source to create a signal; and detecting the signal with a first receiver.

Abstract: Techniques are disclosed relating to performing marine surveys according to dither values generated based on one or more dithering constraints. This may include for example, determining a set of nominal shot points for a marine seismic energy source and determining dither values for ones of the nominal shot points. In some embodiments, the dither values are randomly generated, subject to a duplication constraint such that at most a threshold number of dither differences between consecutive shot points that fall within discrete ranges. In some embodiments, actual shot points are determined for the planned sail line based on application of the determined dither values to the nominal shot points. In various embodiments, the disclosed techniques may facilitate a separate de-blending procedure to separate signals from the marine seismic energy source and signals from one or more other seismic energy sources to be used for the seismic survey.

Abstract: Techniques and apparatus are disclosed for performing marine seismic surveys. In some embodiments, one or more vessels are used to tow a set of streamers and two or more sources such that a first set of sources consists of all those that are disposed within a first threshold distance from the streamers, and a second set of sources consists of all those that are disposed beyond a second, greater, threshold distance from the streamers. Sources in the first set are activated more frequently than sources in the second set are activated.

Abstract: Techniques are disclosed relating to marine geophysical surveys. Various output characteristics of a vibratory source may be modified based on whether a source is targeting an identified portion of a survey area. The portion of the survey area may be detected during the survey or may be pre-identified. In some embodiments, a survey system drives a vibratory source using digital codes having different lengths based on whether the source is targeting an identified portion of a survey area. The disclosed techniques may improve imaging of geology under certain types of formations or may reduce environmental impact, in various embodiments.

Abstract: Methods and apparatus are described for performing a 4D monitor marine seismic survey that repeats a previous survey. A number of sources may be used during the 4D monitor survey that differs from a number of sources that were used during the previous survey. Shot points from the previous survey are repeated by the 4D monitor survey, and additional shot points may be produced during the 4D monitor survey that were not produced during the previous survey. Embodiments enable efficiency and data quality improvements to be captured during 4D survey processes, while preserving repeatability.

Abstract: Methods and apparatus are described for performing a 4D monitor marine seismic survey that repeats a previous survey. A number of sources may be used during the 4D monitor survey that differs from a number of sources that were used during the previous survey. Shot points from the previous survey are repeated by the 4D monitor survey, and additional shot points may be produced during the 4D monitor survey that were not produced during the previous survey. Embodiments enable efficiency and data quality improvements to be captured during 4D survey processes, while preserving repeatability.

Abstract: A method and apparatus for marine surveying. A system includes: a standard-volume source element; a large-volume source element comprising an airgun having a volume greater than 1200 cubic inches; and a long-offset survey streamer. A method includes: towing a standard-volume source element; and towing a large-volume source element; activating the large-volume source element at large shotpoint intervals; and activating the standard-volume source element at standard shotpoint intervals, wherein the large shotpoint intervals are at least twice as long as the standard shotpoint intervals. A method includes: obtaining geophysical data for a subterranean formation; and processing the geophysical data to produce an image of the subterranean formation. A method includes: obtaining a firing plan for a plurality of seismic sources, wherein: a first seismic source of the plurality comprises a large-volume source element, and a second seismic source of the plurality consists of standard-volume source elements.

Abstract: Systems and computer readable media are described that actuate at least one marine seismic source according to a constrained sequence. The sequence exhibits an actuation time or distance interval between each actuation. The actuation time or distance interval corresponds to the sum of a nominal time or distance and a respective dither time or dither distance for each actuation. The sequence is constrained such that differences between consecutive dither times or dither distances remain within a threshold dither difference. Constraining the sequence according to the threshold dither difference enables increased bottom speeds for the source (i.e., increased speeds of the source relative to the seafloor), while still maintaining at least a minimum actuation time or distance interval for the source, taking into account both the nominal time or distance and the respective dither times or dither differences.

Abstract: An actuation location for actuation of a first source coupled to a first marine survey vessel relative to a position of a second marine survey vessel towing a receiver to enhance illumination of a subsurface location can be determined based on a survey route of the second marine survey vessel and a priori data of the subsurface location. The first marine survey vessel can be navigated along a survey route of the first marine survey vessel to the actuation location during a marine survey by changing at least a cross-line position or an in-line position of the first marine survey vessel relative to the survey route of the second marine survey vessel.

Abstract: A medical cooling device for reducing the body core temperature of a patient and a method for operating the same are provided. The cooling process provided by the medical cooling device is based on the state or degree of shivering of the patient.

Abstract: Numerous techniques and apparatus are disclosed relating to the performance of 4D marine geophysical surveys over at least first and second areas covered, respectively, by first and second preexisting baseline surveys. Performing the monitor surveys may include deploying a monitor survey streamer layout that can be used to repeat streamer positions of both the first and the second preexisting baseline surveys, and using the monitor survey streamer layout to perform the monitor survey over the first and second areas in a manner that repeats all streamer positions of the first preexisting baseline survey when over the first area, and that repeats all streamer positions of the second preexisting baseline survey when over the second area. Streamer layouts corresponding to the first and second preexisting baseline surveys may differ in at least one of the following characteristics: streamer separation or total number of streamers.

Abstract: Techniques are disclosed relating to geophysical surveying. In various embodiments, a computer system may access seismic data for a geological formation, where the seismic data is recorded, using one or more sensors, during a seismic survey in which a first vibratory source was driven using a first digital code for at least a first time interval. The first digital code, in some embodiments, may include a first plurality of subsections corresponding to portions of the first time interval. In some embodiments, the computer system may image a first location of the geological formation using a correlation of only a first sub-section of the first plurality of sub-sections with the seismic data. Further, in some embodiments, the computer system may image a second location of the geological formation using a correlation of two or more of the first plurality of sub-sections with the seismic data.

Abstract: A method and apparatus for marine surveying includes: towing sources in a wide-tow source geometry; towing streamers that comprise receivers; actuating at least one of the sources to create a signal; and detecting the signal with a first receiver, wherein: at least one of the source separations or the streamer separations is non-uniform, and the sources and the receivers provide a regular sampling grid for the survey area. A system includes a survey plan; sources in a wide-tow source geometry; and streamers comprising receivers, wherein: at least one of the source separations or the streamer separations is non-uniform, and the sail lines, sources, and receivers provide uniform CMP coverage for the survey area. A method includes operating a system in a survey area, the system having a non-uniform configuration with wide-tow source geometry; actuating at least one source to create a signal; and detecting the signal with a first receiver.

Abstract: Methods and apparatus are described for performing a 4D monitor marine seismic survey that repeats a previous survey. A number of sources may be used during the 4D monitor survey that differs from a number of sources that were used during the previous survey. Shot points from the previous survey are repeated by the 4D monitor survey, and additional shot points may be produced during the 4D monitor survey that were not produced during the previous survey. Embodiments enable efficiency and data quality improvements to be captured during 4D survey processes, while preserving repeatability.

Abstract: Techniques are disclosed relating to performing marine surveys according to dither values generated based on one or more dithering constraints. This may include for example, determining a set of nominal shot points for a marine seismic energy source and determining dither values for ones of the nominal shot points. In some embodiments, the dither values are randomly generated, subject to a duplication constraint such that at most a threshold number of dither differences between consecutive shot points that fall within discrete ranges. In some embodiments, actual shot points are determined for the planned sail line based on application of the determined dither values to the nominal shot points. In various embodiments, the disclosed techniques may facilitate a separate de-blending procedure to separate signals from the marine seismic energy source and signals from one or more other seismic energy sources to be used for the seismic survey.

Abstract: Techniques are disclosed relating to geophysical surveying. In various embodiments, a marine survey vessel may tow a plurality of streamers that each include a plurality of seismic sensors. Further, the survey vessel may tow a plurality of vibratory sources. In various embodiments, a first sweep may be performed, using one or more of the plurality of vibratory sources, for a first time interval. Further, in various embodiments, disclosed techniques may include recording, during the first time interval using the plurality of seismic sensors, seismic data on a tangible, computer-readable medium, thereby creating a geophysical data product.

Abstract: Techniques are disclosed relating to geophysical surveying. In some embodiments, a marine survey vessel tows multiple sensor streamers in addition to vibratory sources deployed relative to the sensor streamers. In some embodiments, the vessel tows vibratory sources emitting energy within different frequency bands in different deployment zones. In some embodiments, one or more sources are driven with different sweep functions, different activation patterns, and/or different sweep lengths. Various disclosed techniques for manufacturing a geophysical data product may potentially simplify equipment used for towing sources, reduce survey complexity without reducing resolution, increase resolution without increasing survey complexity, improve energy content recovered from deep reflections, and/or reduce the environmental impact of emitting seismic energy.

Abstract: A medical cooling device and a method for operating the same are provided.

Abstract: Techniques and apparatus are disclosed for performing marine seismic surveys. In some embodiments, one or more vessels are used to tow a set of streamers and two or more sources such that a first set of sources consists of all those that are disposed within a first threshold distance from the streamers, and a second set of sources consists of all those that are disposed beyond a second, greater, threshold distance from the streamers. Sources in the first set are activated more frequently than sources in the second set are activated.