Publications

The Berai Carbonate is one of the hydrocarbon reservoir targets deposited in the post-rift phase (Late Eocene - Early Oligocene) of the Barito Basin that has been explored by various company since 1960’s. Based on previous studies in Kerendan area (Saller and Vijaya, 2002), the Berai Formation has the potential for reservoir-quality porosity, permeability, and trap volume. In order to identify reservoir potential, a fuller understanding of the Gross Depositional Environment (GDE) is needed. The objectives of the study are to assess potential reservoirs and reservoir geometry based on seismic facies mapping, calibrated with well. Based on eighteen exploratory well all over the basin, well interpretation was initiated with petrophysical analysis to determine carbonate vertical distribution in the well, further supplemented with porosity calculations. Seismic interpretation was based on regional lines across the Berai Carbonate, from which detailed seismic facies mapping assessed the seismic character by using 8,000 km 2D seismic lines. The resultant GDE map is a compilation of well log correlation, regional isopachs, and seismic facies mapping. Based on these well and seismic interpretations, the Berai Formation consists of two dominant ithologies (calcareous shale dominated and l carbonate dominated) deposited within a relatively protected platform interior carbonate environment. The Berai Formation was divided into three depositional cycles (B1, B2, and B3), each with their own lithology character and depositional system: the B1 cycle was dominated by shale facies