Publications

A structural and stratigraphic model can be used to illustrate the basic relationships among source, migration, and reservoir systems and trap associations in the Sunda basin. Lacustrine and paludal shale and coal source rocks are distributed vertically throughout the generative window, ensuring a corresponding continuity of oil generation and primary migration since the inception of each.Migration systems include the basement surface zone, alluvial fans, fluviatile sandstones, transgressive carbonates, and faults. They lie beneath, within, and above the source systems and provide short migration routes from the generative areas to the trap associations at the basin margins. Most important are the fluviatile sandstones, which traverse the basin margins into the depocenters, where they interdigitate with the source systems.All of the oil reserves in the basin are contained within two widespread reservoir systems, fluviatile sandstones and reef-associated carbonates, although several other potential reservoirs are present. The sandstones are best developed at the basin margins where they are optimally located for hydrocarbon migration and trapping. Reservoir facies in the transgressive carbonate system are restricted to the paleohighs, which were shallow and intermittently emergent.The stratigraphic series of source rock, migration, and reservoir systems is capped by a regional claystone seal, which has served as an effective barrier to the vertical migration and escape of hydrocarbons. All hydrocarbons have consequently been forced to migrate laterally to the basin margins and intra-basinal highs, where migration foci have concentrated more than 95% of the basin's 505 MMBO of recoverable reserves in four complex trap associations.