The present disclosure is directed to a helical conveyor for underwater seismic exploration. The system can include a case having a cylindrical portion. A cap is positioned adjacent to a first end of the case. A conveyor having a helix structure is provided within the case. The conveyor can receive an ocean bottom seismometer (“OBS”) unit at a first end of the conveyer and transport the OBS unit via the helix structure to a second end of the conveyor to provide the OBS unit on the seabed to acquire the seismic data. The system can include a propulsion system to receive an instruction and, responsive to the instruction, facilitate movement of the case.

A survey plan is designed and potentially adjusted so that seismic data acquired during the survey include inline and cross-line seismic data irregularities suitable for compressive sensing reconstruction. At least one of the inline and cross-line irregularities is dynamic and may be due to source, vessel(s) and/or streamer steering.

A ribbon-foil depressor is incorporated into a towed seismic array to provide downward lift to array sections or components. The ribbon-foil depressors may be deployed on the port and starboard spur lines or on the outboard separation ropes. The ribbon-foil depressors may be used to submerge and operate seismic equipment at depths as low as 60 m or more and are capable of maintaining towed seismic streamer cables at these depths and still remain stable through various speed changes and turns.

An apparatus for acquiring survey data including streamer equipment comprising a lead-in cable; and a geophysical streamer with a plurality of geophysical sensors distributed along the geophysical streamer, including a forward geophysical sensor; a depressor coupled to the streamer equipment in front of the forward geophysical sensor; a variable tension control device coupled at a back end of the geophysical streamer; and a plurality of tension control system sensors. A method for acquiring survey data including obtaining data from tension control system sensors of a geophysical streamer system; identifying an adjustment to be made to one or more tension control factors of the geophysical streamer system to reduce or control vibrational behavior of streamer equipment of the geophysical streamer system making the adjustment to the one or more tension control factors; and acquiring survey data with the geophysical streamer system.

Depth and tilt control systems for geophysical sensor streamers and methods of use are discussed. Such systems may include a plurality of tilt sensors disposed at spaced apart locations along the geophysical sensor streamer, each tilt sensor having a first tilt sensing element arranged to measure tilt of the geophysical sensor streamer proximate the associated spaced apart location, a plurality of LFD control devices, each disposed proximate one of the tilt sensors along the geophysical sensor streamer, and a plurality of microcontrollers, each microcontroller in signal communication with at least one of the LFD control devices and its associated tilt sensor, wherein each microcontroller is capable of utilizing the tilt measured by the associated tilt sensor to selectively operate the associated LFD control device to cause the geophysical sensor streamer to align with a selected depth profile.

Apparatus and techniques are disclosed relating to towing marine equipment. In some embodiments, a vessel tows equipment through a body of water using a towing member with an associated fairing that includes a slit, such that an axis of the slit is non-perpendicular to a portion of the towing member from which the fairing extends.

A method of controlling a marine seismic streamer towed by a vessel includes deploying a workboat next to a section of the streamer and receiving, at the vessel, from the workboat, a command to enter a maintenance mode. In response, a locking command is transmitted via a streamer data link to direct a bird attached to the streamer to lock movable surfaces thereof. A user interface on the vessel is locked so that control of the bird is no longer available therethrough. A control apparatus for marine seismic operations includes the user interface, a receiver to receive commands from the workboat, a streamer interface to command the birds, a memory recording locations and identifiers of the birds, and a processor configured to carry out the method steps. A marine seismic detection system includes the streamer, a maintenance controller in the workboat, and an integrated navigation system controller in the vessel.

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.