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All Journal Bulletin of Scientific Contribution : Geology IJOG : Indonesian Journal on Geoscience Buletin Sumber Daya Geologi Indonesian Journal on Geoscience Indonesian Journal on Geoscience Jurnal Geominerba Jurnal Geologi dan Sumberdaya Mineral (Journal of Geology and Mineral Resources) Journal of Geosciences and Applied Geology LEMBARAN PUBLIKASI MINYAK DAN GAS BUMI
Ahmad Helman Hamdani
Fakultas Teknik Geologi, Universitas Padjadjaran
Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Earth & Planetary Sciences Education Energy Engineering Environmental Science Other

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Journal : indonesian journal on geoscience

 1 
Biomarker Composition of Some Oil Seeps from West Sulawesi, Indonesia Sutadiwiria, Yarra; Hamdani, Ahmad Helman; Sendjaja, Yoga Andriana; Haryanto, Iyan; Yeftamikha, Yeftamikha
Indonesian Journal on Geoscience Vol 5, No 3 (2018)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.5.3.211-220

Abstract

DOI: 10.17014/ijog.5.3.211-220A suite of oil seep samples collected from the Lariang and Karama Basins, West Sulawesi, Indonesia, have been analyzed using GC and GCMS techniques. Their biomarker compositions have been used to reveal the likely source rock that produces oil. These oil seep samples contain a range in both the concentration of hydrocarbons present and certain level of biodegradation experienced. All sterane m/z 217 data display a familiar pattern of steranes with carbon numbers from 27 to 29 together with pregnane and homo-pregnanes, including rearranged steranes. Triterpane (m/z 191) data show a moderate content of tricyclic terpanes (Tri/C30H), medium to high ratio of norhopane/hopane (C29/C30), and medium to high abundant land plan marker such as resin bicadinanes(Bic/C30H) and oleananes (Ol/C30H). The presence of high abundant oleananes in these samples has been interpreted as the evidence for a marine influence during early diagenesis that may occur by marine or via re-deposition of peat organics in marine sediments. Hence, these results state that the organic matter facies for their source rock oil seep samples from the West Sulawesi region are detected as mixed between allochthonous macerals from typical terrestrial higher plants transported into the basin from distal swamps and soils and some marine organic matter.
Tectonic Control on the Formation of Cleats in the Coal Beds of the Sajau Formation, Berau Basin, Northeast Kalimantan Sudradjat, Adjat; Hamdani, Ahmad Helman
Indonesian Journal on Geoscience Vol 5, No 3 (2018)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.5.3.235-250

Abstract

DOI: 10.17014/ijog.5.3.235-250Coal seams of lignite- to subbituminous rank of Pliocene-age from the Sajau Formation of the Berau Basin are characterized by the presence of a natural fracture system, including cleats. Often, these opening-mode fractures consist of two orthogonal sets (face and butt cleats), both almost perpendicular to the bedding. This paper describes the distribution of orientation, spacing, and aperture of cleats formed in the seams of the Sajau Formation. All observations and measurements were conducted at macroscopic, mesoscopic, and microscopic scales. The butt cleat mean orientations are NE-SW and NW-SE, whereas the face cleat mean orientations are NNE-SSW and NE-SE, and the cleat dip is at a high angle of 75° to the north. The angles between the orientations of these cleat sets are nearly 90°; that is, they are orthogonal. The spacing of the macroface cleats is between 9.52 and 14.46 cm (averaging 11.61 cm), while the spacing of the butt cleats is between 2.3 and 11.3 cm (averaging 5.35 cm). The mean aperture is 0.54 mm. In contrast, the mean spacing of the mesoface cleats is 3.09 mm, and the aperture measurements of these cleats range from 0.0478 to 0.0741 mm (averaging 0.0549 mm). The results obtained from outcrops and X-ray CT (computed tomography) scan clearly indicate that the NNE-SSW face cleat orientations are strictly parallel to the elongation of the main tectonic structures in the studied area. Their origin may be explained by their relationship with local tectonic stress (the maximum principal stress, σ1, was horizontal). Partial least square analysis of data collected from cleats and faults in the area indicates that a power law distribution exists between the cleat characteristics (spacing, density, and aperture), and the distance of the faults (R2 = 0.56). Cleat formation in the Sajau Formation was mainly controlled by the mechanical response to tectonic stresses, which generated a unique cleat network in the coal. Based on the SEM photography, it is concluded that the development of microcleats in the Sajau Formation resulted from both endogenic processes and tectonic activities as indicated by the change in the shape of the cleats, from straight line to curved shape and branching (intersection of multiple cleats that form a conical network at the end).
Co-Authors Abbas - Adjat Sudradjat Adjat Sudradjat Afriadhi Triwerdhana Agus Didit Haryanto -, Agus Didit Haryanto Andriana, Yoga Ardiansyah, Muhammad Iqbal Arista Muhartanto Arista Muhartanto, Arista Chairul Nas Dandy, Leonardus Edy Sunardi Faizal Muhamadsyah, Faizal Irfan Marwanza Iyan Haryanto Johanes Hutabarat Khoirullah, Nur Lili Fauzielly Muhamadsyah, Faisal Muhammad Afrizal Ie Muhammad Iqbal Ardiansyah Nisa Nurul Ilmi Nurdrajat Nurdrajat Safrizal Safrizal Safrizal Sudradjat, Adjat Theresa Naomi Putri Triwerdhana, Afriadhi Winantris Winantris Yarra Sutadiwiria Yeftamikha Yeftamikha Yeftamikha, . Yeftamikha, Yeftamikha Yeftamikha, Yeftamikha Yoga Adriana Senjaya -, Yoga Adriana Senjaya Yoga Andriana Sendjaja