Position challenges marine seismic

摘要

In the '80s, a typical marine seismic spread consisted of two streamers and two sources. Source and receiver group positions were calculated based on nominal offsets. Streamer compasses were used to calculate streamer shape and finally receiver group positions. Navigated tailbuoys were not used. Navigation processing could, in principle, not be solved by traditional surveying techniques as the system was singular. The processing of the navigation data was performed in the office and could in some instances take more than 6 months. The period from the late '80s to early '90s introduced laser, acoustic range observations and navigated tailbuoys. Vessel, source and streamers were tied together with observations, and the streamers became part of a closed traverse. Navigation processing could be solved by traditional surveying techniques, and redundant observations became part of the calculations. The processing turnaround was greatly improved by bringing the navigation processing department onboard. By the end of this period some vessels could tow six streamers, and multi-vessel operations could include up to 12 streamers.