Publications

Legacy seismic data in the Makassar Straits has a challenging signal to noise ratio in the shallow water areas, because of strong multiple reflections. Through a detailed analysis of the legacy input data, we have developed a processing sequence with optimized parameters to address the challenges present in the legacy data. Recent seismic reprocessing efforts, featuring both source and receiver adaptive deghosting , tailored demultiple workflows, and contemporary velocity model building and imaging technologies, like Q tomography, visco-acoustic full-waveform inversion (Q-FWI) and Q pre-stack depth migration have significantly enhanced data quality. Applying the contemporary tools available has notably improved the imaging of direct hydrocarbon indicators (DHIs) in the region. Flat spots that were previously not well imaged are much improved, which has derisked the remaining undrilled structures in the Makassar Straits area. The Makassar Straits is home to the Kutei Basin, especially the toe thrust zone in the deep-water region. Upper Miocene Turbidite Sand (Sepinggan Formation) is the primary target of Geng North-1 and other exploration wells in this region. The anticlines in this toe thrust zone are generally associated with hydrocarbons if the structure has a visible DHI. The latest seismic reprocessing images show that DHIs and flat spots and bright spots are visible in existing discovery fields while not visible in dry structures hence allowing more confident prospect de-risking through the area. This paper demonstrates the significant improvement in the seismic data quality which will lead to the unlocking of the remaining potential of the Makassar Straits. The success of Geng North indicates that there is a great prize to be found in the region and the reprocessing indicates that there are still many undrilled structures with encouraging DHIs.