CHARACTERISTIC OF OLIGOCENE SHALE IN WARUNG KIARA AND CILETUH, SUKABUMI DISTRICT, AS A POTENTIAL SHALE GAS SYSTEM

• Main Author: SAPUTRO (NIM: 22015022), ZUNARTO
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/31929
• Institution: Institut Teknologi Bandung

<p align="justify">The success story of shale gas development in several countries, such as United States and Canada had triggered most countries to find out the potential in their own areas, included Indonesia. The Indonesian government has undertaken some development in this nonconventional sector (energy diversification) through Presidential Regulation No.5 of 2006. Therefore, research about the potential of shale gas in nonconventional systems needs to be improved as one source of energy that can be developed to support the energy needs in Indonesia. <br /> <br /> <br /> <br /> Bogor Basin, which is located in western Java has thick shale layer that deposited during the Eocene to Oligocene period. During the Oligocene period, tectonic activity in Bogor Basin was not so significant, where the sea level and coastline continued to rise then deposited finer sediments. This dark-colored clay material contains a considerable amount of organic material and has potentially to be evaluated to know the ability in producing hydrocarbon. <br /> <br /> <br /> <br /> The characteristic of Oligocene Shale in research area is known by conducted geological mapping, geochemical analysis, and petrography analysis. Geological analysis includes reconstruction of depositional environment and paleontology analysis. The geochemical analysis includes TOC test, Rock Eval Pyrolysis and vitrinite reflectance analysis. The petrographic analysis includes the identification of minerals, calculation of rock brittleness index and observation of pore type and pore size. <br /> <br /> <br /> <br /> The result of geological mapping show that shale at Warung Kiara was deposited during the Early Oligocene period in the submarine fan environment while the shale in the Ciletuh area was deposited in Early to Middle Oligocene in transitional sedimentary environment. XRD data shows mineral composition are dominated by clay minerals and quartz and also very small amount of carbonate. The brittleness index shows shale are at less brittle (BI: 0,31 – 0,43) to brittle (BI: 0,51 – 0,55) conditions for both locations. <br /> <br /> <br /> <br /> The result of geochemical test shows that the shale at the research area show relatively high (TOC), values ranging from 1,67 – 2,75% which means classified as good source rock and potentially generated hydrocarbon. Tmax value and vitrinite reflectance indicate that the degree of maturity is at the immature level until early mature. Kerogen type classified into type III and IV (HI: 6,81 – 61,30 mg HC/g TOC). Based on the results of this study, shale in research area have unfavorable potential as a shale gas system. In other hand, reconstruction of regional geological map showing the widespread distribution of Oligocene Shale on subsurface opens up opportunities for further evaluation taking into consideration that outcrop shale have good values both in TOC and brittleness. <p align="justify"> <br />