A marine seismic acquisition system includes a frame that includes a central longitudinal axis and members that define orthogonal planes that intersect along the central longitudinal axis; a data interface operatively coupled to the frame; hydrophones operatively coupled to the frame; a buoyancy engine operatively coupled to the frame where the buoyancy engine includes at least one mechanism that controls buoyancy of at least the frame, the hydrophones and the buoyancy engine; and at least one inertial motion sensor operatively coupled to the frame that generates frame orientation data, where the hydrophones, the buoyancy engine and the at least one inertial motion sensor are operatively coupled to the data interface.

Buoyant tail section of a geophysical streamer. At least some of the example embodiments are methods of performing a geophysical survey in a marine environment, the method including: towing an active section of a geophysical streamer in the marine environment, the active section having a buoyancy; towing a tail section, the tail section coupled to a distal end of the active section, the towing of the tail section by way of the active section, and at least a portion of the tail section having a buoyancy that is both positively buoyant and greater than buoyancy of the active section; towing a tail buoy in the marine environment, the tail buoy coupled to a distal end of the tail section, and the towing of the tail buoy by way of the tail section; and gathering geophysical survey data by way of the active section.

A seismic acquisition system. The seismic acquisition system may include at least one unmanned water vehicle. The seismic acquisition system may also include at least one seismic streamer coupled to the at least one unmanned water vehicle, where the at least one seismic streamer has one or more seismic sensors coupled thereto for recording seismic data in a survey area. The seismic acquisition system may further include a buoyancy compensation mechanism coupled to the at least one seismic streamer, where the buoyancy compensation mechanism is configured to orient the at least one seismic streamer between a generally vertical direction and a generally horizontal direction through a water column.

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 seismic streamer can include an outer tube that defines an interior space; sensor packages disposed in the interior space; and spacers disposed in the interior space where the spacers include swellable material.

A seismic streamer can include an outer tube that defines an interior space having a longitudinal axis; sensor packages disposed in the interior space at respective positions along the longitudinal axis; a rope disposed in the interior space and offset from the longitudinal axis; and gel filled foam disposed in the interior space at least in part between the sensor packages and at least in part about portions of the rope where the gel filled foam includes a water swellable material that, responsive to a breach in the outer tube and contact with water, transitions the gel filled foam from an unswollen state to a swollen state that hinders gel leakage from the breach in the outer tube.

A marine seismic acquisition system includes a frame that includes a central longitudinal axis and members that define orthogonal planes that intersect along the central longitudinal axis; a data interface operatively coupled to the frame; hydrophones operatively coupled to the frame; a buoyancy engine operatively coupled to the frame where the buoyancy engine includes at least one mechanism that controls buoyancy of at least the frame, the hydrophones and the buoyancy engine; and at least one inertial motion sensor operatively coupled to the frame that generates frame orientation data, where the hydrophones, the buoyancy engine and the at least one inertial motion sensor are operatively coupled to the data interface.

Embodiments herein describe techniques for performing acoustic imaging when collocated pressure and three-directional pressure gradient measurements are available. Such measurements become available through the use of a hydrophone and a 3-component geophone or accelerometer when the containing node is neutrally buoyant, or nearly neutrally buoyant, and is coupled to the water column, rather than grounded and thus coupled to the ocean bottom sediments.

Geophysical sensor cables. At least some of the example embodiments are sensor cable sections including hydrophone groups defined along a geophysical sensor cable section, the hydrophone group may include: a substrate of flexible material having electrical traces thereon, the substrate within the internal volume or embedded within the outer jacket, and the substrate having has a length measured parallel to the longitudinal axis; and a plurality of hydrophones mechanically coupled to the substrate. The substrate may have a variety of shapes, including one or more strips, helix, double helix, and cylindrical.

A system can include a float, a winch, a line, and a collapsible fairing. The winch can be coupled to the float. The line can be associated with the winch, where the winch is configured to extend and retract the line. The collapsible fairing can surround the line. Extension and retraction of the line can cause the collapsible fairing to extend and collapse.