A case study of shallow marine survey for geohazard risk evaluation, offshore Iran

Summary Detecting shallow geohazard risk is one of the critical challenging issues during well drilling for gas fields development. 3D conventional seismic surveys typically contain information from deep parts, since they are designed for deep reservoir targets. In current study, several 2D high resolution seismic data with dense line spacing were acquired for shallow geohazard evaluation over a shallow marine gas field, offshore Iran. Such data is beneficial in terms of available near offset information which are necessary for shallow marine hazards evaluations. On the other hand, 2D imaging cannot be accurate to distinguish correct subsurface location of the drilling hazardous features. In this situation, pseudo- 3D migration is an appropriate method to achieve the correct subsurface image with more details relative to 3D conventional seismic. Pseudo-3D cube generation also has some other advantages that can be profitable in seismic data interpretation including: 3D attribute calculation, surface (horizon) attribute estimation, 3D geo-body extraction and accelerating seismic data interpretation procedure.