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A Large-Scale Gulf of Mexico OBC Simultaneous-Source Case Study: Survey Design for Efficient Shot Separation
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 81st EAGE Conference and Exhibition 2019, Jun 2019, Volume 2019, p.1 - 5
Abstract
Acquiring seismic data with simultaneous sources, already an established technique for land data, is gaining acceptance for towed-streamer marine data, and is fast becoming the norm for ocean-bottom data. Simultaneous-source acquisition is especially attractive because it can potentially improve both acquisition efficiency and data quality. The average shot time interval is reduced, often dramatically, and vessel and crew productivity are correspondingly increased. This, together with the improved ability to handle interference, also reduces and relaxes time-share requirements. Multiple source vessels increase flexibility in the acquisition geometry, allowing recording longer offsets and richer azimuth distributions. These benefits can materialize if we are able to separate the simultaneously acquired shots, preserving the primary shot energy whilst attenuating the interference from other shots. We achieve this through detailed survey design based on modelled data. This procedure allows us to determine the most efficient design consistent with our understanding of the geology and the objectives of the survey. We focus on an ocean-bottom cable (OBC) survey from the southern part of the Gulf of Mexico. The shallow-water data are acquired using multicomponent point-source point-receiver technology over an area of 4,000 km². The project covers multiples provinces and has a very complex geological structure.