Publications

Fluid inclusion analysis provides important information for evaluating seal quality, hydrocarbon emplacement and diagenetic histories that are critical to understanding factors controlling the distribution of hydrocarbon accumulations. The FIV technique is a screening tool for hydrocarbon occurrence that can be used to identify hydrocarbon migration pathways. Hydrocarbon migration routes are recognized by anomalies in presence and strength of gas and liquid FIV compounds. The FIV response and geochemical fingerprinting from selected wells in the Cepu Block, East Java, suggests that all wells in hydrocarbon accumulations experienced an early charge of waxy, terrestrial oil. Most structures also experienced a later gas charge. The FIV analysis demonstrates large variability in top-seal capacity that is related to the environment of deposition of the sealing facies. This variability in top-seal capacity is thought to impact gas-cap distribution and column height. In several wells, paired assemblages of co-existing water and hydrocarbon-bearing fluid inclusions were observed in euhedral dolomite. Formation of euhedral dolomite was followed by pore-filling clear calcite cement where precipitation temperatures are derived from associated fluid inclusion assemblage trapping temperatures. Analysis of these paired assemblages indicates entrapment of both under-saturated and saturated oil. Furthermore, homogenization temperatures suggest that numerous paired inclusions were trapped at temperatures at and above present-day temperature. These observations lead to new insights into the hydrocarbon emplacement history and controls on hydrocarbon distribution on the Cepu Block.