A method and apparatus for data acquisition including: acquiring a first set of data for a survey area with streamer receivers on a streamer spread; and simultaneously acquiring a second set of data for the area with ocean bottom receivers, the first and second sets of data together forming a complete dataset for velocity modeling and imaging. A method including: navigating a first propulsion source along a first path in the area, wherein a streamer spread and a first seismic source are coupled to the first propulsion source; navigating a second propulsion source along a second path in the area, wherein a second seismic source is coupled to the second propulsion source; while navigating the first and second propulsion sources, activating at least one of the first and second seismic sources; and acquiring data with receivers on the streamer spread and with ocean bottom receivers distributed throughout the area.

A long-offset acquisition system includes a source vessel; a signal source coupled to the source vessel; and a long-offset streamer coupled to a survey vessel and including an aft-most receiver, an offset of the aft-most receiver being at least 12 km. A long-offset acquisition method includes towing a signal source with a source vessel; towing a first long-offset streamer with a survey vessel; and acquiring data with receivers of the first long-offset streamer. A long-offset acquisition method includes towing a signal source with a first survey vessel; towing a long-offset streamer with a second survey vessel, the long-offset streamer having a plurality of receivers; actuating the signal source while an offset between the signal source and at least one of the plurality of receivers is at least 15 km; and acquiring data with receivers of the long-offset streamer.

A vessel is configured to tow a marine seismic source, a spread of standard-offset streamers, and a long-offset streamer in a manner such that: a standard streamer maximum offset, measured from the at least one source to an aft-most receiver in the standard-offset streamers, is not more than 20 km; and a long-offset streamer maximum offset, measured between the at least one source and an aft-most receiver in the long-offset streamer, is longer than the standard streamer maximum offset and is between 12 km and 40 km. In some embodiments, the long-offset streamer and the standard-offset streamers are coupled to a same spreader line. In other embodiments, the long-offset streamer is coupled to the vessel by a long-offset lead-in line. In still other embodiments, the standard-offset streamers are coupled to a first spreader line, and the long-offset streamer is coupled to a second spreader line disposed aft of the first spreader line.

A system and method for acquiring seismic streamer data is provided. Embodiments may include performing a marine seismic survey using an unmanned marine vessel having a power source configured to drive and provide propulsion to the unmanned marine vessel. Embodiments may further include acquiring one or more of long and ultra-long seismic survey data using a multi-dimensional seismic sensor array coupled with the unmanned marine vessel and providing the seismic survey data as a reduced data set that includes long and ultra long offsets.

Described herein is a method for performing a long offset refraction seismic survey of a subsurface area of interest using a fiber-optic cable (170) positioned on or under the earth's surface and extending between a first cable end (172) closer to the area of interest and a second cable end further from the area of interest, the method comprising: connecting an interrogator to an end of the fiber-optic cable, wherein the interrogator is configured to emit light into the cable through the end and detect reflected light from the cable; simultaneously steering and activating a low frequency seismic source and operating the interrogator to collect seismic refraction data; wherein steering the source comprises directing the source along a travel path that extends between a first source position closer to the area of interest and a second source position further from the area of interest, wherein the second source position is horizontally offset at least 9 km from the first cable end, and the cable and source travel path extend in opposite directions away from the area of interest, and processing the collected refraction data to build up an image of or extract information about the subsurface area of interest.