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oa Ocean Bottom Seismic - the Original Broadband - How Nodal Technology and Blended Sources Make it Cost Effective
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, EAGE/SPG Workshop on Broadband Seismic, Jun 2014, cp-403-00015
- ISBN: 978-90-73834-93-4
Abstract
Broadband marine is not new - the original method for broadband marine data acquisition by combining vector (vertical geophone) and scalar (hydrophone) data was proposed by Milo Backus in 1958! (Water Reverberations--Their Nature and Elimination, Geophysics, 1958). This ocean bottom dual sensor approach has been applied, primarily for appraisal and development applications, for a many years worldwide but the scale of the surveys, by dint of their focus on field specific imaging objectives, has been limited compared to towed streamer surveys in both size and duration. One of the challenges set by the oil companies has been to reduce the unit costs of ocean bottom data – “If only the square kilometer rates were lower we would shoot more data” is a common mantra. The difficulty in doing this has been the inherent technical downtime experienced by all the contractors operating ocean bottom systems – the terminations, connectors, power distribution and data telemetry components within a traditional ocean bottom cable (OBC) system are inherently prone to failure due to the intrinsic nature of the cable deployment/recovery cycle where the cables are stressed and de-stressed every time they are laid onto/recovered from the seabed. It is akin to recovering and deploying the full streamer spread every line change for towed streamer operations.