Publications

Tanjung field is Pertamina's long-time producing field in Barito basin with cumulative production of 168 MMBO. The field relies on a Lower Tanjung reservoir play discovered in 1937. The reservoir has been carefully characterized using Tanjung 3D seismic acquired in 1997. Lower Tanjung was deposited in a transgressive megasequence. Sand A to E are existing and productive in Tanjung, Kambitin, and Bagok Field. Kambitin, however, is missing sand A, B, and C and only producing from sand D and E. In 2013, Pertamina EP acquired a new 3D seismic covering a larger Kambitin Area. The main exploration target is sand A and B, hypothetically a more proximal deposit in Tanjung fluvio-deltaic system. Since sand A and B are absent in Kambitin field, both Kambitin and Tanjung 3D seismic are needed for reservoir characterization. However, a slice of RMS amplitude shows that Marlin 3D seismic and Tanjung 3D seismic have an amplitude discrepancy, which prevents the interpreter to properly characterize the reservoir. Using both seismic separately to characterize the reservoir quality yields to a low geological chance factor. Because both new and old survey were acquired and processed using different design and parameter, the discrepancy cannot be handled by only applying a scalar. Pertamina EP has reprocessed both seismic simultaneously by regularizing fold, azimuth, and amplitude. We handled difference in geometry using 5D regularization and interpolation. The process includes fold optimization for both image quality and computation cost.The amplitude and acoustic impedance of the reprocessed surveys prove the above hypothesis. AI map of the reprocessed data enables interpreters to better characterize reservoir distribution. Equalized amplitude allows using Tanjung data as analog for reservoir characterization in Marlin structure and increases the geological chance factor. This study has opened a new opportunity near an existing field and increased the chance factor by reprocessing the new and legacy survey simultaneously.