Publications

The seismic database utilised for the Kumawa PSC 2D PSDM (prestack depth migration) project includes approximately 5,400 full fold km of multi-vintage 2D lines (roughly 2 km line spacing in the east-west direction, 4 km in the north-south direction). In this area, the geologic structure and associated seismic velocity model are extremely complex. In order to achieve the best possible imaging results using 2D seismic in an area with complex 3D geology, an advanced depth imaging workflow was developed. The key elements of the workflow are:  using iterative, 3D grid-based tomographic earth modeling technology to produce an accurate global velocity model  building a layer-based anisotropy model without well constraints  using the final 3D velocity model for 2D anisotropic depth migration. This case study will describe a workflow using 3D tomography technology to derive a robust earth model and subsequent depth imaging in the Kumawa PSC 2D PSDM project area. Seismic comparisons demonstrate significant imaging improvements using anisotropic depth imaging technology compared to PSTM (prestack time migration) imaging results. In addition, the imaging earth model is consistent across the project area.