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Case Study - The Application of Low-frequency Vibrator in 3D Seismic Re-survey for Sub-salt Targets in Kazakhstan
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 77th EAGE Conference and Exhibition 2015, Jun 2015, Volume 2015, p.1 - 5
Abstract
The masking of salt body with high velocity has always been a confusing problem in seismic survey for sub-salt targets. The low-frequency components of seismic signal have a stronger penetration than high frequency ones due to the attenuation characteristics during propagation, which can be instrumental in sub-salt seismic survey. Due to the limitations of mechanic system and hydraulic system, the sweep frequency usually starts at 5–6Hz for conventional vibrator. This paper introduces a new type of low-frequency vibrator that can start at 3Hz with full force drive and presents its application and results in 3D seismic re-survey for sub-salt targets in Kazakhstan. The result of source parameter test presents that the low-frequency vibrator has an excellent capability of emitting low-frequency energy, which can obtain the reflection signal below 2Hz. The final source parameters were determined for broadband and high productivity acquisition and significantly improved the quality of 3D seismic data for sub-salt targets. The final data proved the 3D seismic re-survey achieved excellent results.