IDENTIFICATION OF BIOGENIC GAS POTENTIAL USING INTEGRATED SEISMIC DATA, WIRELINE LOG AND GEOCHEMISTRY DATA; A STUDY CASE: MURIAH SUB-BASIN, BAWEAN ARC, OFFSHORE NORTHERN EAST JAVA

摘要

The research area is located in the sub - basin of the Muriah and Bawean Arc in the offshore area of Northern East Java. Integration of Seismic data, wireline log and geochemistry data are used to determine the main reservoirs in the research area, to know the distribution and accumulation and also to understand the most potential points containing biogenic gases. The result of the research is the main reservoir to be an exploration target is Ngrayong Formation (sandstone) and Kujung 1 Formation (limestone), while genetics of biogenic gas in the research area is formed in Kujung II Formation as a source rock that have temperature at 400 - 700°C with Ro 0.35, which expulsed at last Oligocene and formed in Muriah sub-basin at 800 m below the surface. One of the important things is to find the accumulation point of hydrocarbon accumulation, as evident by the discovery of biogenic gas at KPD wells (> 98% Methane). It can be interpreted that in adjacent areas entering the window of biogenic gas maturity and having coal content and having a low geothermal gradient have had a potential area for biogenic gas that can be developed. The distribution of the biogenic gas is controlled by the NE-SW geological structure, while the accumulation of biogenic gas in addition to the hydrocarbon reservoir factor itself is controlled by hydrocarbon traps located in the research area, such as structural and stratigraphic traps.