TGS successfully reprocessed 6,600 km of legacy 2D data in the Natuna Basin using advanced broadband seismic processing and Dynamic Matching Full Waveform Inversion (DM FWI). This resulted in a regionally consistent 2D grid, allowing key wells in both West and East Natuna to be linked, including the significant Natuna D Alpha gas field and the Paus block. East Natuna presents stratigraphic traps with generally high CO₂ gas, whilst West Natuna features inverted anticlines with diverse oil and gas fields.

This study further enhances the Natuna dataset by integrating relative extended elastic impedance (rEEI) of angle stacks, with the aim of revitalizing exploration in this offshore basin. The rEEI method is derived solely from seismic data and employs AVO concepts to distinguish lithology and fluid, bolstering confidence in seismic accuracy. Furthermore, a global analysis of velocity and density coupled with rEEI aids in fluid anomaly screening. While robust and efficient, the process may yield false positives, necessitating well data as crucial blind tests to build confidence and guide derisking efforts in discriminating lithology from fluid.

Considering potential challenges, such as high velocity contrasts from volcanics, carbonates and coals impacting results, ongoing investigations explore the use of velocity constraints, relative velocity differentiation, and lithology masking. This combined weighting of geological attributes aims to boost confidence in rEEI interpretation for describing discovered and potential reservoirs. This research will significantly contribute to understanding the offshore Natuna Basin’s geological nuances, facilitating well-informed exploration decisions, and potentially revealing untapped hydrocarbon resources.