SHALE GAS CHARACTERIZATION OF OUTCROP OF KOPAI AND PINIYA FORMATION, AKIMEUGAH BASIN, IN WAMENA AND SURRONDINGS, PAPUA

• Main Author: Daniel, Berkat
• Format: Theses
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/33273
• Institution: Institut Teknologi Bandung

Energy needs in Indonesia are increasing over time, but the reserves of energy resources in Indonesia have not been able to meet these energy needs. Shale gas can be an alternative energy source to meet energy needs in Indonesia. To determine the potential of shale gas in a field, characterization of shale gas needs to be done. In this study characterization of shale gas in the outcrops of the Kopai Formation and the Piniya Formation, Akimeugah Basin, in the Wamena and surrounding areas, Papua Province. The two outcrops of this formation have fairly thick flakes. To find out the character of shale gas in these two formations, we need to know some information about the depositional environment, formation age, porosity type, mineralogy, agility index, and wealth, type of organic material and maturity level. The steps taken to find out these things include measurement / observation of stratigraphy, fossil analysis, petrographic analysis, X-Ray Powder Diffraction (XRD), Scanning Electron Microscopy (SEM), and geochemical analysis. The results of stratigraphic cross section measurements and fossil analysis showed that the Kopai Formation was deposited in the transition-shorefaces (marine realm) environment, while the Piniya Formation was deposited on the shelf (marine realm) environment. The thickness of the shale in the Kopai Formation outcrop varies in thickness between 2-40 m, while the thickness of the shale in the outcrop of the Piniya Formation is 3-41 meters. In general, the mineralogical content using XRD shows the composition of quartz, mica and clay minerals in the form of ilite and chlorite with a greater percentage than kaolinite minerals. This also supports evidence that the two outcrops of the formation were deposited in the marine realm. The brittleness index uses the Jarvie’s and Wang’s equations and the Altamar and Marfurt’s classifications show the rock brittleness of the Kopai Formation and the Piniya Formation are brittle. From the results of the petrographic and SEM analysis, the porosity of the fracture developes at the upper part of the Kopai Formation and the Piniya Formation, where fractures in the upper Piniya Formation appeare to have recrystallized quartz cement. Porosity due to dissolution develops in the lower Kopai Formation which in the Formation Piniya doesn't develop. Based on the results of geochemical data, the upper Kopai Formation in the study area has poor organic matter with a TOC value of <0.5%, while the organic matter in the lower Formation Kopai isn’t available. The organic material richness of the Lower Piniya Formation has organic material richness which is relatively richer than the upper, it is 0.52% up to 1.45% (medium to good shale), while the lower part is only 0.42% and 0.83% (poor and fair shale). The type of organic material in both formation outcrops shows type III and type IV. The maturity level of the Tmaks data and the vitrinite reflection that shows the maturity level mature to mature mature has made the vitrinite maseral less and left only type IV maseral (inert).