Overcoming shallow water imaging challenges in Australia’s North West Shelf

The North West Shelf, situated in Western Australia, is a world-class offshore hydrocarbon province. The presence of hard water bottom, near water bottom reflectors and shallow Tertiary carbonates not only generates strong multiples but also distorts the ray-paths for deeper reflectors. Seismic data quality is severely deteriorated due to residual multiples, limited bandwidth, and poor signal-to-noise ratio, impeding reservoir delineation and further AVO/QI analysis. With the recent advancement of seismic imaging technologies, we propose an integrated workflow including (1) comprehensive demultiple and (2) hybrid tomography and Time-lag Full-Waveform Inversion (TLFWI) to overcome these long-standing imaging challenges. The significant uplift of the reprocessed image provides deeper insights into the subsurface geology and improves confidence of prospect mapping for exploration.