Publications

The Kutei Basin, located in eastern Kalimantan, is unique within Indonesia in having a complete, preserved Paleogene to Recent sedimentary section. Petrographic analysis conducted on well core and sidewall core data, outcrop data and seismic shothole samples for conventional sandstone reservoir characterization purposes also provides the essential data for source provenance studies.Three distinct petrologic types of Early Miocene to Recent age sediments are found within the Lower Kutei Basin.Framework grain component distributions classify the source provenance terrain as recycled orogenic for all age:s of sediment studied.The Early Miocene age (23-17 ma) sandstones are moderately quartzose with a moderate lithic component. These sandstones are derived from the Cretaceous age Rajang Group of metasediments. There is a subsidiary, but significant volcanic lithic component that records continuous volcanic activity throlughout this period. The Pliocene to Recent age sandstones are also of this type.The end of the Early Miocene to earliest Middle Miocene sandstones are volcanogenic. These sandstones record an increase in volcanic activity in western Kalimantan between 17 - 14.5 million years ago.Highly quartzose sandstones of Middle and Late Miocene age form the reservoirs in the giant oil and gas fields along the coastline and offshore. These sandstones are recycled products of basin inversion events that advanced progressively from west to east. The onset of basin inversion is interpreted to have commenced at N10 time (14.5 ma). There is no associated volcanic activity recorded in the sediment record.