Publications

One of the main challenges in reservoir characterization is to representatively model the reservoir architectures and reservoir property heterogeneity. Precise sedimentological understanding of the reservoir from the study of an outcrop analogue can significantly improve the modeling process.New road construction in the Samarinda area has generated freshly exposed outcrops of Middle Miocene deltaic deposits. Detailed study of these outcrops has been performed. The outcrops represent a 450 m thick succession of deltaic/shallow marine sediments. A number of deltaic cycles that were controlled by either allocyclic or autocyclic processes were identified and are bounded by flooding surfaces.Sedimentary lithofacies are grouped into 5 facies associations. Facies associations include: (1) distributary channel, (2) fluvial channel, (3) distributary mouth-bar, (4) prodelta and, (5) floodplain/interdistributary/tidal flat. The depositional environments and paleo-water depths of each facies were estimated based on their facies associations.The vertical stacking pattern of sediments shows overall thickening upward sequences interpreted as indicating regressive evolution of deltaic parasequences. Similar patterns have been observed in the subsurface of Middle-Upper Miocene deposits from which the majority of the hydrocarbons are produced in the Mahakam area.This outcrop analogue study will be used to calibrate the reservoir characterization process and reduce the uncertainties associated with modeling and upscaling.