The research area is situated in the Eastern Arm of Sulawesi, Banggai Basin. The complexity of geological components in Sulawesi greatly affects the pattern of sedimentary rocks. Certainly, these conditions have implications of the petroleum system in this basin. The characterization of carbonate rock in the Banggai Basin requires the integration of multi-disciplines in order to conduct reservoir characterization on a detailed scale. This study focuses on integrating surface to subsurface sedimentology aspects to evaluate the reservoir characterization. The two methods are used to analyzed, the surface field observation and subsurface study. These methods will then be assisted by several methods, such as petrographic analysis, XRD and SEM, biostratigraphic analysis, and routine core analysis. The outcrop sampling is carried out in the northward and subsequently integrated with subsurface in the southward (Tiaka-Tiara Field). In the surface area, Tomori Formation has two part, Lower Tomori Formation is composed of Large Foram-Red Algae facies with deposited inner-middle sublittoral. Wherein, Upper Tomori Formation is composed of planktic-large foram packstone-wackestone with deposited Middle-Outer Sublittoral and skeletal packstone-wackestone with deposited Inner-Middle Sublittoral. Minahaki Formation is overlying of Tomori Formation, there are two facies namely large foram packstone-mudstone with deposited at Middle Sublittoral-Upper bathyal and skeletal packstone-wackestone with deposited at Inner-Middle Sublittoral. The youngest formation of the Salodik Group on the surface is Mentawa Formation where this member is reefal facies. On the subsurface, the Salodik Group consists of Tomori Formation, Matindok Formation, and Minahaki Formation. The Tomori Formation was deposited at Bathyal-Inner shelf with mudstone-grainstone facies and slightly dolomite. Younger than Tomori Formation on the subsurface is calcareous sedimentary rocks, known as Matindok Formation. The Minahaki Formation was directly overlying the Matindok Formation in the transgressive phase.

The eastern part of the Makassar Strait has not achieved significant success in the petroleum exploration stage. In general, exploration wells in this area have not found hydrocarbons to date. Most of the problems experienced by these wells are geochemical-related, including the absence of a source rock where the hydrocarbon is formed, immature source rock, and low volume of hydrocarbon. Therefore, this study aims to find potential Eocene source rock in West Sulawesi. It commenced by determining the paleofacies followed by the geochemical analysis of well cutting and surface samples. The geochemical analyses conducted are total organic carbon (TOC), rock eval pyrolysis (REP), kerogen type, vitrinite reflectance (VR), and gas chromatography/mass spectrometry (GC/MS). The samples that have a potential as an Eocene source rock were coal, as well as carbonaceous and marine shale. Based on the plotting of relative abundance for sterane (C 27 -C 29 ), the coal and carbonaceous shale had the input from terrestrial organic material with a contribution from marine, while marine shale had the input from marine organic material and contribution from terrestrial. Furthermore, coal and carbonaceous shale had a relatively high proportion of C 29 sterane compared to C 27 and C 28 , while marine shale had a relatively high proportion of C 27 compared to C 28 and C 29 . The higher plants also contributed to the organic matter in carbonaceous shale and coal samples, as indicated by the abundance of oleanane/C 30 hopane and the other significant content of resin biomarker. In accordance with the objectives of the study, it was found that during the Eocene, the type of source rock in the eastern side of the province varied, starting with coal and carbonaceous shale in the upper intertidal-fluviodeltaic environment, and marine shale sediments from the source facies of marine algal.

<div><table cellspacing="0" cellpadding="0" align="left"><tbody><tr><td align="left" valign="top"><p>Sumur eksplorasi LYS dan KYS merupakan dua sumur pertama yang dibor di Blok Bdg, daratan Sulawesi Barat oleh kontraktor Wilayah Kerja Eksplorasi. Beberapa analisis dan evaluasi geokimia dilakukan pada sampel sumur LYS dan KYS, yaitu analisis karbon organik total (TOC), <em>rock eval pyrolysis</em> (REP), reflektansi vitrinit (VR), jenis kerogen, kromatografi gas (GC), dan kromatografi gas/spektrometri massa (GC/MS). Untuk mengilustrasikan perbedaan dalam sejarah pembenaman dan kematangan thermal antara sumur LYS dan KYS, pemodelan sejarah pembenaman dan kematangan thermal telah dilakukan pada kedua sumur ini. Sumur LYS-1 merupakan sumur darat dangkal yang hanya melakukan penetrasi hingga Miosen Awal, yang secara thermal belum matang, sedangkan sumur KYS menembus hingga Eosen. Sedimen berumur Eosen diasumsikan matang lebih awal (sekitar 10Ma), karena adanya sedimen berumur Oligosen dan Miosen yang lebih tebal. Berdasarkan nilai TOC, VR, Tmax, profil kematangan, dan pemodelan sejarah pembenaman dan thermal dari sampel sumur LYS dan KYS, diasumsikan bahwa sampel sumur KYS lebih matang dibandingkan sampel sumur LYS.</p></td></tr></tbody></table></div>

<p class="Abstract">Daerah penelitian lapangan “X” terletak di Formasi Kais, Cekungan Salawati, Papua Barat, Indonesia. Maksud dan tujuan dari penelitian ini adalah untuk menginterpretasikan fasies karbonat, beserta penyebarannya, baik secara vertikal maupun horizontal. Penelitian dimulai dengan penafsiran <em>litostratigrafi</em> menggunakan data <em>log</em> dan sayatan tipis, untuk membuat <em>type log</em>. Dilanjut dengan analisis sikuen stratigrafi dan <em>reef system</em> untuk menentukan penyebaran, dengan bantuan data seismik untuk dikorelasikan dengan sumur-sumur lainnya. Dari hasil analisis, terdapat 5 fasies pada daerah penelitian, yaitu: <em>Skeletal Debris Packstone-Wackestone, Coral Algal Grainstone – Boundstone, Skeletal Wackestone, Skeletal Packstone dan Coral Algal Packstone</em>. Terdapat pula 4 <em>reef system</em>, yaitu; <em>Back reef, reef crest, fore reef dan off reef</em>. Untuk mencapai tujuan akhir dari penelitian ini, maka dibuat peta penyebaran fasies.</p>

Global climatic event on Middle Miocene triggered by geology activity is called by Mid-Miocene Climatic Optimum (MMCO). This event was widely distributed and associated with increasing temperature and CO 2 content in the atmosphere. The effect of MMCO was widely known the mid-latitude region, but still limited information in low latitude sediments. This study try to perform the effect of MMCO at Cibulakan Formation in which deposited in the low latitude basin, Bogor Basin.Fifty eights samples from Cileungsi River were taken at Cibulakan Formation and quantitative nannoplankton analysis was carried out for this study. Nannoplankton shows the sensitive response with sea surface temperature changes. Increasing of total population nannoplankton indicates the rising of temperature and dropping temperature is marked by decreasing population. The effect of sea surface temperature changes relates with salinity changes as the effect of evaporation. Helicosphaera carteri and Umbilicosphaera jafari were counted to know the salinity trend at Cibulakan Formation.Sea surfaces temperature changes was observed on Early Miocene which was influenced by small scale Early Miocene glaciation and active tectonic during this period. Warming temperature taken place on Middle Miocene as the effect of warm and open sea during Mid Miocene Climatic Optimum. Afterwards, hot temperature continued on Late Miocene triggered by global increasing temperature at Pacific Ocean and widely distribution of clean water at North West Java Basin.