SAMODRA, ARI, LINDY ROTINSULU, NANANG MUCHSIN, and ENRICO NGANTUNG
Pertamina, Jakarta, Indonesia

Abstract: Integration of Re-interpreted Seismic and Basin-modelling: A Case Study

A new look on the Maniso area has breathed new life for exploration there. Newly interpreted horizons that are used in a 1D basin-modelling indicated the presence of lacustrine depositional environment. Analysis on oil shows indicates that the oils were generated from mature lacustrinic source.

The seismic reflector geometries in Maniso area illustrate four seismic sequence sets each separated by strong reflectors. The interpretation of these sets involves a system where initially the rate of sedimentation is at a minimum and then kept pace with subsidence. Seismic section expression of dip line is that the steep dips are due to the deposition of the sequences.

Sedimentation of these sequences is extremely influenced by a major fault trending relatively North-South which also formed a half-graben system. The Pre-Rift phase can be identified in seismic section, followed by a Syn-Rift phase, Early Post-Rift phase, and ended by a Post-Rift phase characterized by sub-parallel reflections. Hydrocarbons are assumed to accumulate within the seismic sequence sets of the Early Post-Rift phase.

Two-dimensional basin-modelling program indicated that the oils generated could migrate within the seismic sequence sets and accumulated in the stratigraphical traps.

Amplitude Versus Offset study also confirms the trend of these seismic sequence sets. We believe that the study area is still potential enough to discover stratigraphical prospects.

AAPG Search and Discovery Article #90928©1999 AAPG Annual Convention, San Antonio, Texas