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Planktonic Foraminifera Biostratigraphy of the Pliocene Kintom and Bongka Formation, Central Sulawesi, Indonesia Novian, Moch. Indra; Barianto, Didit Hadi; Husein, Salahuddin; Surjono, Sugeng Sapto
Journal of Tropical Biodiversity and Biotechnology Vol 9, No 4 (2024): December
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jtbb.94685

Abstract

The Pliocene sediments exposed in the eastern arm of southern Sulawesi consist of Kintom and Bongka Formations, thought to be the result of collisions in the Middle Miocene. The research area is located along the Matindok – OndoOndolu road, Banggai Regency, Central Sulawesi Province. The aims of the research is to determine the rock units that developed in the Kintom – Bongka Formation and determine the chronological time frame based on planktonic foraminifera biostratigraphy. This research used stratigraphic measurement on a scale of 1:100 and Plio-Pleistocene planktonic foraminifera biostratigraphy. A lithological column along 315 meters divided into three rock units. The marl unit and calcareous sandstone unit show characteristics similar to flysch deposits from the collision and are part of the Kintom Formation. Intergrade conglomerate gravelly sandstone deposited unconformably on top of the previous unit is part of the Bongka Formation. This last unit shows characteristics similar to molasse deposits. In total of 46 rock samples were analyzed for foraminifera biostratigraphy. Seven foraminifera biozones showing the age of rock deposition from the Early Pliocene to the Late Pleistocene.The order of the foraminifera biozone is Globorotalia tumida Brady LOZ (PL1a; 5.59 - 4.45 Ma), Globoturborotalita nepenthes Todd CRZ (PL1b; 4.45 - 4.39 Ma), Globotalia acostaensis Blow PRZ (PL2a; 4.39 – 4.31 Ma), Globotalia margaritae Bolli HOZ (PL2b; 4.31 - 3.85 Ma), Sphaeroidinellopsis seminulina Schwager HOZ (PL 3-4; 3.85 – 3.20 Ma), Globorotalia (M) miocenica Palmer/Globorotalia miocenica Palmer HOZ (PL5–6; 3.20 – 2.30 Ma), and Pulleniatina praecursor Banner & Blow HOZ (PL6–PT1a; 2.30 – 2.26 Ma).
Sebaran Batuan Karbonat Di Cekungan Matarombeo, Lengan Tenggara Sulawesi Samodra, Saptono Budi; surjono, sugeng sapto
Geosfera: Jurnal Penelitian Geografi Vol 3, No 2 (2024): Geosfera: Jurnal Penelitian Geografi
Publisher : Universitas Negeri Gorontalo

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37905/geojpg.v3i2.29077

Abstract

Carbonate rocks, especially reef, are an exploration target for sedimentary basins that are still beginning to be explored. In the Matarombeo Basin, there are 5 rock formations composed of carbonate rocks, namely the Tokala Formation, Matano Formation, Tampakura Formation, Eomoiko Formation and Buara Formation. The aims of this research are to determine the distribution of the five carbonate rock formations and their potential as hydrocarbon reservoirs in the study area.. The data used is data from surface geological investigations and seismic data. From the analysis results it is known that carbonate rocks from the Tampakura Formation and the Eomoiko Formation can function as the main reservoir in the Matarombeo Basin. This is based on the physical properties of the rock which has fairly good porosity and permeability, and can be easily recognized in seismic sections as reef growth. The existence of reefs that grow at heights and are connected to the interior which can function as a kitchen area causes the limestone of the Tampakura Formation and the Eomoiko Formation to become the main reservoir targets in the Matarombeo Basin.
Lithofacies, Facies Association, and Depositional Environment of 34-1, 33-6, and 33-4 Sandstone, Wida Field, Gita Member, Talang Akar Formation, Asri Basin, Offshore Southeast Sumatra Saputra, Adi Danu; Surjono, Sugeng Sapto; Winardi, Sarju; Setyadi, Abdul Latif; Ralanarko, Dwandari
Jurnal Ilmiah Geologi PANGEA Vol. 11 No. 1 (2024): Jurnal Ilmiah Geologi Pangea
Publisher : PROGRAM STUDI TEKNIK GEOLOGI FAKULTAS TEKNOLOGI MINERAL UPN VETERAN YOGYAKARTA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/jigp.v11i1.12011

Abstract

Three Gita Member reservoirs 34-1, 33-6, and 33-4 produce from solution gas drive with rapid pressure decline and low recovery factor. After successful oil production enhancements through waterflooding injections prompt the need for a reservoir model in further field development. Before such models were built reservoir characterization was carried out to determine facies and depositional environment for facies modeling. The study integrated core, wireline log, petrophysical logs, seismic attribute, petrography, etc. Next, well correlation was carried out to distribute stratigraphic markers. Finally, seismic attribute and well correlation were integrated to construct pie chart and depositional environment map. External geometry from seismic attribute revealed distributary channel with point bars which act as reservoir and consist of medium-fine grained planar tabular cross bedding sandstone, mud drapes sandstone, and ripple-wavy lamination sandstone. The wireline log showed fining-upward pattern and core displayed abundant channel rip up clasts, sharp or erosional contact with underlying lithology. Frequent mud drapes found within channel sandstone indicate tidal influence in proximity to marine environment probably in lower delta plain. Channels are trending west-east (34-1) and north-south (33-6 and 33-4). Other facies associations are shallow marine, swamp, interdistributary bay, and tidally influenced interdistributary bay. Shallow marine FA consists of skeletal limestone (Lm), calcareous mudstone, and calcareous sandstone (Sc). Rootlet mudstone (Fb) and interlamination of carbonaceous mudstone with very fine-grain sandstone (Fl) formed interdistributary bay FA. Swamp FA consists of coal and coaly mudstone. Tidally influenced interdistributary bay FA consists of carbonaceous laminated mudstone high in carbon (Flb), intensely bioturbated carbonaceous mudstone (Flb), very finely laminated mudstone-very fine grain sandstone (Fl) and black fissile shale (Fm).
The Comparation of Water Saturation Approaches to Reveal a Low Resistivity Reservoir Potential Case in Gumai Formation, South Sumatra Basin Dhea Adisty Pratami; Sarju Winardi; Sugeng Sapto Surjono; Widi Atmoko
Scientific Contributions Oil and Gas Vol 46 No 2 (2023)
Publisher : Testing Center for Oil and Gas LEMIGAS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.46.2.1563

Abstract

The LRLC reservoir zone has been identified in SN-3 well, at the DAP-1 interval on Gumai Formation. This interval has a low resistivity value from 3-5 ohm.m and the drill stem test (DST) results show oil with gas without water. This study is objected to identify the causes of LRLC reservoir in gumai formation and finding a suitable sw calculation method. Some data such as well logs, reports, cores, and XRD are used to calculate petrophysical parameters such as Vsh, Phie, and Sw, and would be validated by DST data. Water saturation (Sw) calculations from Archie and the CEC method (Waxman Smits, Dual Water, Juhasz) were performed and the results were compared. The results showed that the main cause of the DAP-1 interval LRLC zone was the presence of clay minerals consisting of mixed layers (Illite/smectite). These clay minerals will be associated with high cation exchange capacity (CEC) values, with the value 70 (meq/100g), which can increase conductivity and reduce resistivity values. Based on lumping the more optimistic results of sw calculation from Waxman Smits Sw method (Sw based on CEC method). The DST data on the SN-3 well does not have water test data, so the calculation of the Sw value that is close to the Swirr value is considered the most suitable Sw for the low resistivity reservoir conditions of the Gumai Formation in the study area. The best practice for low resistivity reservoir for suitable petrophysical calculation is necessary to pay attention to the rock lithology conditions, the presence of mineral clay, and determining suitable Sw appropriate to the reservoir conditions
Quantifying the Impact of Siderite Composition and Reservoir Resistivity (Rt) on Water Saturation Estimation in Low-Resistivity Sideritic Sandstone Reservoirs Using the Graphic Plot Method Sarju Winardi; Sugeng Sapto Surjono; Donatus Hendra Amijaya; Wiwit Suryanto
Scientific Contributions Oil and Gas Vol 47 No 2 (2024)
Publisher : Testing Center for Oil and Gas LEMIGAS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.47.2.1619

Abstract

The case studies on low-resistivity-low-contrast (LRLC) reservoirs have started using a conductive matrix model approach based on the assumption that the rock matrix is composed of conductive minerals. The previous studies on reservoir resistivity (Rt) against conductive-minerals-rich sandstone were limited to pyritic types without developing the others such as the sideritic which was found in Indonesia. Therefore, there is a need to determine the relationship between siderite volume within the sandstone reservoir and the reduction number of Rt. Relation profiles were applied to accurately estimate the actual water saturation (Sw) while the resistance of the sandstone samples was determined through the voltage (V, volt) and current (I, ampere). The samples were designed as pseudo-core in the laboratory and simulated to have siderite composition in the range of 0-30% followed by the injection of brine at different saturation conditions. The Rt was calculated through the modification of Wenner and Ohm’s Law and later compared graphically with siderite volume of each Sw line. It was observed from the results that siderite led to an exponential reduction in Rt value. Moreover, the threshold volume of siderite required to reduce Rt significantly to 50% of the original value was found to be 6%. The actual Sw was later estimated simply through the application of the Graphic Plot Method from the curves
The origin and evolution of the Menui Basin, part of the Matarombeo Terrain, Southeastern Arm of Sulawesi, Based on Geological and Geophysical Data Samodra, Saptono Budi; Surjono, Sugeng Sapto; Amijaya, Donatus Hendra; Suryanto, Wiwit
Indonesian Journal of Geography Vol 57, No 3 (2025): Indonesian Journal of Geography
Publisher : Faculty of Geography, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijg.113432

Abstract

Menui Sub-basin is a part of Matarombeo terrain, located in south-east arm of Sulawesi Island – Indonesia. Matarombeo terrain geologically is bounded by Matano Fault, Lawanopo Fault, and Tolo Trust. Different from western part of Matarombeo Terrain that consist of Mountain, Menui Sub-basin is located at eastern part of Matarombeo Terrain, covered by sea water of Tolo Bay. The aim of this research is to interpreted basin formation and evolution of Menui Sub-basin, based on geomorphological and geological observation, further than stratigraphic and structural analysis. Research method included IFSAR image interpretation, geological field observation, and laboratory analysis such as petrography, paleontology,  structural geology and sub surface analysis. Geologic and structural geology data were collected from surface mapping in land of Matarombeo, but sub-surface interpretation beneath Tolo bay were taken from gravity and seismic data. Stratigraphically, study area consist of Cretaceous – Oligocene ophiolite series which thrusted above Mesozoic sedimentary rocks from the continental crust origin. Unconformably above those two rock groups deposited molasse group on Miocene. The study area has been affected by three different tectonic stress phases.  Formation and evolution of Menui Sub-Basin is characterized by several distinct events. The events begin from its history as part of Australia (pre-rifting sequence), the detachment from Australia (syn-rifting sequence), movement to its present location (syn-drifting sequence) and during and after the collision with SE Sulawesi (syn-orogen and post-orogen sequences).Received: 2025-11-24 Revised:  2025-12-13 Accepted: 2025-12-31 Published: 2025-12-31