Seamless Multi-Survey Depth Imaging for Regional CCS Screening: Paving the Way for CCS, Offshore Western Australia

Australia is committed to reducing its emissions by 43% by 2030 and achieving net-zero greenhouse gas emissions by 2050. The Barrow and Dampier sub basins in Western Australia have been identified as potential carbon capture and storage (CCS) sites. To assess the area’s suitability for CCS projects, reprocessing of data from 29 legacy surveys covering 34,000 square kilometers across various water depths was required. The primary objective of the reprocessing was to produce a high-quality seamless regional-scale seismic image.

A tailored depth imaging strategy was employed. This involved building an optimal initial velocity model to be used for full-waveform inversion (FWI) and common-image-point (CIP) tomography. The integrated workflow resulted in a seamless velocity model encapsulating trends that reflected the regional geology, which was instrumental in delineating subsurface structures and mitigating risks.

The signal processing of the seismic data was undertaken using a uniform workflow across the 29 legacy surveys. Utilizing the velocity model produced through FWI and CIP tomography, pre-stack Kirchhoff depth migration (KDM) was used to generate a contiguous image. The seamless merged volume created by the reprocessing will be valuable for structural mapping and identification of CCS storage sites, reducing interpretation uncertainty for subsequent regional studies.