Paper Summary
The East Java Basin is a prolific hydrocarbon province in Indonesia in which exploration plays have typically targeted the pinnacle reefs of the Oligocene-Miocene Kujung carbonates. Robust imaging of the deeper section however has historically been challenged due in part to the limited bandwidth of conventional seismic data. A further challenge arises from the imaging artifacts introduced at the overlying Wonocolo carbonate platform, where the slow velocities of deep channel incisions are in strong contrast with the fast carbonate velocity. Prestack depth migration can be used to address this issue, but requires a velocity model with sufficiently high spatial and temporal resolution to precisely capture such velocity variations. To this aim, Full Waveform Inversion is used in the velocity model building. Whereas legacy data in the basin has struggled to image deeper than the Kujung level, seismic acquisition and imaging methods are now providing data with greater bandwidth and deeper penetration of signal. In Madura, the deeper Eocene Ngimbang formation as well as basement are now much better resolved, opening up the potential play in the Ngimbang clastics.