Publications

The North Barito Basin in Central Kalimantan is a frontier exploration area which until recently has received little attention from the oil and gas industry. Since 2015, ConocoPhillips Kalimantan Exploration (CKEL) and Petronas have conducted an extensive exploration program in the Kualakurun Block using high resolution satellite data, newly acquired 2D seismic, gradiometry, outcrop strike-dip measurements, biostratigraphy and geochemical analysis of outcrop samples. The results of this program have shed new light into the geology and prospectively of this area. Previous hypotheses of the Kualakurun area suggested it was a stable platform characterized by thin Tertiary sediment onlapping the Schwaner Complex and therefore had little exploration potential. Recently acquired gravity and 2D seismic data shows that the western area of the block consists of rifted basins oriented NE-SW, which are interpreted to be a continuation of the South Kutai regional trend. The rift basins were formed in the Eocene and filled with lacustrine shale and high Hydrogen Index coal source rocks deposited within fluvio-deltaic to lacustrine setting, mimicking petroleum systems in the extensively explored Sundaland rift basins in Indonesia. This area was later inverted during Plio-Pleistocene shortening, transforming the paleo horst blocks to present day lows and the paleo graben/half-grabens to present day structural highs. In the eastern part of the block, there are several low amplitude structures formed by differential compaction over basement high and later amplified by the Plio-Pleistocene uplift. The observed structures on the block coupled with information obtained through the exploration program provides positive evidence that there is a working petroleum system in the Kualakurun area and that these structures could be the focus of hydrocarbon migration. The results from this exploration program demonstrates that early assumptions and interpretations of frontier areas can be misleading resulting in opportunities being overlooked. It is through a thorough and focused exploration program that the potential in Kualakurun was identified.