Lessons Learned From the World's Largest Continuous Onshore and Offshore 3D Seismic Survey

Abstract

In 2017 ADNOC decided to cover the entire Abu Dhabi Emirate, onshore and offshore, with high- resolution and high-fold 3D seismic. Acquisition of the world's largest continuous seismic survey started in late 2018 and is around 77% complete at the time of writing. Data processing is well under way and interpretation of the first delivered 3D cubes is ongoing. Now is an opportune time to review the status of this gigantic project and draw preliminary lessons. Comparison with legacy data shows a massive improvement in deep imaging, which was one of the main objectives of this survey. The basement can clearly be interpreted, while it is hardly visible on legacy data being covered with high energy multiples. A thorough analysis demonstrated that increased offset is the main reason for the uplift. The large fold and the low frequency sweep also help recover signal down to 3 Hz. This extends the bandwidth in the low frequencies by one to two octaves compared to legacy data, which tremendously benefits structural interpretation and stratigraphic inversion.