Presented are methods and a system for efficiently acquiring seismic data based on a virtual seismic spread. A streamer vessel and a source vessel are used in combination and in a specific spatial arrangement collect seismic data. The source arrays can be fired simultaneously, creating blended seismic data that is separated with a deblending algorithm or sequentially to collect seismic data directly. The virtual seismic spread can be configured to reduce survey time or decrease capital costs and health safety and environment exposure based on the size of the streamer array towed by the streamer vessel.

An autonomous underwater vehicle (AUV) for guiding other AUVs during a marine seismic survey. The guiding AUV includes a housing; a propulsion system located inside the housing; and an acoustic positioning system attached to an outside the housing. The acoustic positioning system emits at least three chirps from three different locations.

A subaqueous underground survey system using a reflection seismic survey method includes: multiple sound sources 1 for generating sound waves in the water; a controller 2 for controlling phases of the sound waves; a geophone 3 for receiving reflected waves of the sound waves; and an observation ship 4 equipped with the sound sources 1, wherein the controller 2 controls phases of the sound sources 1 so that the sound waves generated from the respective sound sources 1 have a phase difference at a water bottom surface B, thereby controlling generation of shear waves to propagate into the ground.

A seismic apparatus includes one or more seismic cable systems configured to acquire seismic data, each seismic cable system having one or more of a cable jacket, a reservoir for a ballast fluid or other ballast medium, and an actuator or other transfer mechanism configured to transfer the ballast fluid between the reservoir and the seismic cable system during acquisition of the seismic data, e.g., where the ballast fluid is transferred to the seismic cable system within the cable jacket. A controller can be configured to adjust a buoyancy of the seismic cable system responsive to the transfer of the ballast fluid, e.g., where the internal volume expands or contract based on the fluid transfer.

A control system for a towed object (1, 6; 20; 30; 50) in or on a body of water comprise one or more towing members (3) extending between the object (1) and a towing vessel (2). One or more ballast members (4) are movably connected to a respective one of said one or more towing members (3) and controllably movable at least a distance along its respective towing member. The towed object (1) may be controlled by moving one or more ballast members (4) on a towing member (3) in order to control the catenary (c) of a towing member (3). Individual ballast members (4) may be manipulated individually in order to correct, preserve or otherwise change the geometry of a trawl.

Marine survey. The various embodiments includes both methods and systems. At least some of the illustrative embodiments are methods including: deploying a spreader structure from vessel into a body of water, wherein the spreader structure defines a deployed width of one kilometer or more; coupling a plurality of sensor streamers to the spreader structure; and towing the plurality of sensor streamers through the water, where the horizontal separation between the sensor streamers is at least partially maintained by the spreader structure. The spreader structure provides horizontal separation sensor streamers without the use of a tensioning force applied to the spreader structure.

A sea bed survey system being configured to be towed by a towing body (12) is provided. The system comprises at least one sensor carrier (100) having a plurality of sensors (128) disposed along its length, and at least one deflector (110) for controlling the lateral extension and the vertical position of said sensor carrier (100), wherein the lateral extension exceeds 25% of the length of sensor carrier, and the vertical height above the sea bed is less than the lateral extension of said sensor carrier.

A technique includes receiving data acquired by a seismic sensor on a spread of at least one streamer. The data are indicative of a seismic source signature that is produced by a source seismic to penetrate into the Earth to acquire geophysical information in connection with a seismic survey. The technique includes processing the data to determine a position on the streamer relative to a reference position not disposed on the streamer.

A sonar device intended to be towed by a surface ship and includes a tow cable and a set of at least one towed device, comprising a towed body, intended to be towed by the surface ship via the tow cable, the towed body being elongate along a longitudinal axis from a first longitudinal end of the towed body as far as a second longitudinal end of the towed body, the towed body incorporating a first linear acoustic antenna comprising a plurality of electroacoustic transducers substantially aligned along the longitudinal axis, the towed device being configured and connected to the tow cable in such a way that the towed body is able, when it is being towed and is fully submerged, to exhibit an orientation the longitudinal axis extends substantially along a vertical axis defined by the force of gravity, at least one towed body of the set of towed bodies being connected to the tow cable by a first hanger and a second hanger of substantially the same length, a first end of the first hanger and a first end of the second hanger being connected to the tow cable and a second end of the first hanger being attached to the towed body at a fixing point of the towed body which point is situated near the first longitudinal end and a second end of the second hanger being attached to the towed body at a second fixing point secured to the first fixing point and situated near the second longitudinal end.

A seismic node deployment system comprises a cable supply with one or more seismic nodes configured for coupling to the cable at one or more attachment locations for deployment to a water column. A node attachment system is configured to drive a portion of the cable into periodic or reciprocal motion so that the attachment speed is substantially reduced relative to the speed at which the cable is deployed.