SHALE GAS CHARACTERIZATION OF BAYAH FORMATION IN GUNUNG WALAT AND SURROUNDING, SUKABUMI REGENCY, WEST JAVA

• Main Author: AGRI KHARISA (NIM: 22015314), NINDA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/29659
• Institution: Institut Teknologi Bandung

<br /> <p align="justify">Fossil fuel energy needs in Indonesia continue to increase every year, but it is not balanced with the increase in the amount of oil production. But on the other hand, gas production is bigger than oil production in recent years, so Indonesia still has huge natural gas potential to increase national gas reserves. There are some options to increase gas reserves in Indonesia. One of them is through unconventional energy exploration, such as shale gas. <br /> <br /> In shale gas exploration process, the geological aspects such as distribution, deposition, and characteristics of shale become one of the issues that needs to be studied in this research area where located in Gunung Walat and surrounding, Sukabumi, West Java. In study area, there are shale of Bayah Formation that widely exposed. Therefore, to know outcrop shale characterization of Bayah Formation in relation to shale gas reservoir, it is necessary to conduct several steps of analysis such as stratigraphic measurement section (MS), fossil, mineralogy, and geochemistry. In MS process is obtained columns and stratigraphic correlation. Fossil analysis uses palinology. Mineralogy analysis include petrography, X-Ray Powder Diffraction (XRD), and Scanning Electron Microscopy+Energy Dispersive X-Ray (SEM+EDX). Geochemical analysis include total organic carbon (TOC), pyrolysis, and vitrinite reflectance (Ro). <br /> <br /> Based on the results of stratigraphic analysis in research area are known that Bayah Formation at lower part deposited in deltaic environment, then gradually changes to meandering river, and at upper part tends to become braided river. Shale intervals that exposed in study area are relatively thick with thickness vary from 1-30 meter, which characterized by flood plain and delta plain deposition. The fossil analysis result based on pollens and spores findings from all samples, strengthen the stratigraphic results, which deposition environment is in freshwater area. Next, from the mineralogy results provide information about brittleness index of rock that Bayah Formation shale in general can be categorized as less brittle to brittle (0.320 - 0.694) and only a little as less elastic (0.194 - 0.224), so this can give indication that shale in Bayah Formation is quite well to apply the hydraulic fracturing. In addition, several samples of shale in study area, there are many pores in organic matter and micropore due to the dissolution process, which is amount of significant gas content in shale gas is absorbed in organic material and non-organic matrix. Based on geochemical analysis shows that shale of Bayah Formation in study area has organic material richness range from fair to excellent (0.69% - 8.44%). Then, in pyrolisis analysis is applied to sample which have TOC value above 1%. From that analysis, in general kerogen type of shale are III (gas) and only a small number as kerogen type IV (inert). Based on Ro value, shale termal maturity level range from immature to mature (0.422% - 0.910%), but based on Tmax value are at immature to post mature (429.200C - 498.800C). <br /> <br /> Therefore, based on the integration of geochemical, stratigraphic, and mineralogy analysis results, shale of Bayah Formation characteristics in Gunung Walat and surrounding has good potential as shale gas reservoir, so it can be further explored. <br /> <p align="justify">