1. Field of Invention
The present invention relates to the field of marine seismic instrumentation and methods of using same. More specifically, the invention relates to systems and methods for positioning one or more spread elements of a marine seismic spread using information about the ocean current ahead of the towing vessel.
2. Related Art
Marine seismic exploration investigates and maps the structure and character of subsurface geological formations underlying a body of water. For large survey areas, seismic vessels tow one or more seismic sources and multiple seismic streamer cables through the water. The entire system is typically referred to as a spread, and the elements making up the spread are referred to as spread elements. The seismic sources typically comprise compressed air guns for generating acoustic pulses in the water. The energy from these pulses propagates downwardly into the geological formations and is reflected upwardly from the interfaces between subsurface geological formations. The reflected energy is sensed with hydrophones attached to the seismic streamers, and data representing such energy is recorded and processed to provide information about the underlying geological features.
While there have been some efforts to use information regarding environmental conditions, including ocean currents, previous attempts have not provided the desired precision in positioning marine seismic spread elements.