Broadband seismic imaging and analysis of offshore thrust belt for frontier exploration

Abstract

The case study was carried out in the Babar Selaru PSC block in East Indonesia in 2014. The block is located in southern Outer Banda Arc which was developed by the Neogene collision between the Sunda and Australia plates. The southern Outer Banda Arc is characterized by complex structural elements consisting of a series of Paleozoic and Mesozoic basins on the Australian Continental Plate and the Neogene Banda Arc thrust belt. 3D broadband seismic data and appropriate PrSDM imaging technique provided us significant improvements in seismic imaging for both thrust complex and sub-thrust structures. Broadband 3D seismic imaging contributed better recovery of seismic energy from deep sections where conventional seismic imaging could not reveal any reflections. Pre-migration deghosting technology provided us the stable phase of wavelets and desired broadband frequency spectrum in the seismic image. The velocity model constructed from the combination of Kirchhoff PrSDM and Controlled Beam Migration provided better resolution and continuity of seismic images under thrust complexes by overcoming the poor illumination issue. The seismic image with broadband frequency contributed to evaluating fluid effect in shallow section, reducing depth structure uncertainty in poor illumination area and interpreting lateral lithological change in deep reservoir section.