Reservoir Characterization of the Terumbu and Arang Formations Using Model-Based Seismic Inversion in the East Natuna Basin
DOI:
https://doi.org/10.29017/scog.v49i1.1979Keywords:
Reservoir characterization, acoustic impedance, Model-Based Inversion, Carbonate Reservoir, East Natuna Basin, Arang Formation, Terumbu FormationAbstract
The Miocene carbonate buildup and fine-grained clastic sequence constitute the main reservoir and sealing intervals in the East Natuna Basin. This study characterizes the reservoirs of the Terumbu and Arang Formations using an integrated workflow that includes petrophysical analysis, sensitivity analysis, depth structure mapping, and model-based seismic inversion. Well-log interpretation shows clear lithological contrasts between the two formations. The Terumbu carbonates exhibit very low gamma-ray values (18 to 24 API) and high porosity, ranging from 28 to 37%, with neutron–density crossovers indicating gas-bearing intervals, particularly in the GADO-3 well, where resistivity values range from 852 to 1958 Ω·m. In contrast, the Arang Formation is characterized by high gamma-ray values (102 to 148 API), higher clay volume (30 to 44%), and low porosity (<10%). P-impedance–density cross-plots distinguish carbonate rocks (4,500 to 10,000 g/cc·m/s; 1.7 to 2.35 g/cc) from shale and shaly sand with higher impedance and density. Depth structure mapping reveals a central–northern structural high that is favorable for reef development and fault-related trapping. Model-based seismic inversion further reveals low-to-moderate impedance (4,100 to 6,156 g/cc·m/s), low density, and high inverted porosity within the Top Terumbu interval, indicating excellent reservoir quality. Overall, the results indicate that the Terumbu Formation forms the primary carbonate reservoir, while the Arang Formation mainly acts as an effective regional seal in the petroleum system of the East Natuna Basin
References
Anselmetti et al., 1993, Control on Sonic Velocity in Carbonates, PAGEOPH Vol. 141 No 2/3/4, Birkhauser Verlag, Basel.
Anselmetti et al., 1997, Acoustic properties of Neogene carbonates and siliciclastics from the subsurface of the Florida Keys: implications for seismic reflectivity, Marine Geology 144 9-13, Elsevier Science B.V.
Anselmetti et al., 2003, Factor controlling elastic properties in carbonates sediments and rock, The Leading Edge, SEG, United States.
Ashraf. U. et al., 2022, Estimation of porosity and facies distribution through seismic inversion in an unconventional tight sandstone reservoir of Hangjinqi area, Ordos basin, Front. Earth Sci. 10:1014052. doi: 10.3389/feart.2022.1014052.
Asquith & Krygowski, 2004, Basic Well Log Analysis, The American Association of Petroleum Geologist, Oklahoma.
Assefa S. et al., 2003, Velocities of compressional and shear waves in limestone, Geophysical Prospecting 51, 1-13, European Association of Geoscientists Engineers.
Bashir Y. et al., 2021, Seismic expression of miocene carbonate platform and reservoir characterization through geophysical approach: application in central Luconia, offshore Malaysia, Journal of Petroleum Exploration and Production Technology (2021) 11:1533–1544.
Bashir Y. et al., 2024, Cohesive approach for determining porosity and P impedance in carbonate rocks using seismic attributes and inversion analysis, Journal of Petroleum Exploration and Production Technology (2024) 14:1173–1187.
Cakra. Y.I., 2021, Evaluating Oligocene Intra Platform Reef Carbonate Reservoir Potential Using Advance Model of Seismic Facies Analysis and Seismic Inversion A Case Study Barito Basin Indonesia, PROCEEDINGS JOINT CONVENTION BANDUNG (JCB) 2021.
Chopra & Marfut, 2007, Seismic Attributes for Prospect Identification and Reservoir Characterization, Society Of Exploration Geophysicits, Oklahoma.
Darman. H, 2017, Seismic Expression Of Key Geological Features In The East Natuna Basin, Berita Sedimentologi, Indonesia.
Durrani. M.Z.A et al., 2021, Characterization of carbonate reservoir using post-stack global geostatistical acoustic inversion approach: A case study from a mature gas field, onshore Pakistan, Journal of Applied Geophysics 188 (2021) 104313.
Dewan. J.T., 1983, Essential of Modern Open-Hole log Interpretation, PennWell Publishing Company, Oklahoma.
Dvorkin, J., et al., 2014, Seismic Reflections of Rock Properties. Cambridge Univ. Press. United States.
Ellis. D & Singer. J., 2007, Well Logging for Earth Scientists, Springer, Dordrecht Netherlands.
El-Sayed. A.S. et al., 2024, Utilizing post-stack seismic inversion for delineation of gas bearing sand in a pleistocene reservoir, baltim gas field, nile delta, Egypt, scientific reports, natureportofolio.
Espejel. R.L., et al, 2019, Distribution and growth styles of isolated carbonate platforms as a function of fault propagation, Marine and Petroleum Geology Volume 107, September 2019, Pages 484-507, Elsevier.
Falade. A.O. et al., 2024, Hydrocarbon prospective study using seismic inversion and rock physics in an offshore field, Niger Delta, Research Discover Geoscience, Discover.
Handoyo, H., Ronlei, B. C., Wibowo, A. S., Sigalingging, A. S., Nathania, E. Y., Fatkhan, F., Erdi, A., ... & Husein, A. A. A. (2025). Reservoir Characterization of Ngrayong Formation, Sandstone with Carbonate Intercalation, Using a Geostatistical Approach Based on Petrophysical Parameters, Northeast Java Basin, Indonesia. Scientific Contributions Oil and Gas, 48(3), 237-251. https://doi.org/10.29017/scog.v48i3.1828
Handoyo. H. et al., 2024, Characterization of Carbonate Reservoir Potential in Salawati Basin, West Papua: Analysis of Seismic Direct Hydrocarbon Indicator (DHI), Seismic Attributes, and Seismic Spectrum Decomposition, Indonesian Journal on Geoscience Vol. 11 No. 2 August 2024: 173-188.
Hendry. J. et al., 2021, Seismic Characterization of Carbonate Platforms and Reservoirs, Geological Society London Special Publications, 509,1–28, The Geological Society of London.
Hutchison. C., 2014, Tectonic evolution of Southeast Asia, Bulletin of the Geological Society of Malaysia, Volume 60 pp. 1-18, Malaysia.
Janjuhah. H.T. et al., 2021, Integrated Porosity Classification and Quantification Scheme for Enhanced Carbonate Reservoir Quality: Implications from the Miocene Malaysian Carbonates, Journal of Marine Science and Engineering, 9,1410, MDPI, Switzerland.
Johnson. A.B. & Cullen A.B., 2023, Continental rifting in the South China Sea through extension and high heat flow: An extended history, Gondwana Research 120 (2023) 235-263, Elsevier.
Kessler F. & Jong. J., 2016, The South China Sea: Sub-basins, Regional Unconformities and Uplift of the Peripheral Mountain Ranges since the Eocene, Berita Sedimentologi, Indonesia.
Koesoemadinata, R.P., 1980, Geologi Minyak dan Gas Bumi, Jilid 1, Institut Teknologi Bandung, Bandung.
Kuszpit W.K & Sowizdzal K., 2024, Integration of Well Logging and Seismic Data for the Prognosis of Reservoir Properties of Carbonates, Energies 2024, 17, 355, MDPI, Switzerland.
Larki E. et al., 2023, A new insight to access carbonate reservoir quality using quality factor and velocity deviation log, Acta Geophysica (2024) 72:3159–3178.
Lauwijaya W.S. et al., 2024, Integrated Reservoir Characterization in a Newly Discovered Area of the South Mahakam Cluster: Navigating Challenges and Opportunities, PIT IAGI BALIKPAPAN 2024.
Lindseth, R.O., 1979, Synthetic sonic logs-a process for stratigraphic interpretation, Geophysics Vol. 44 No 1 P. 3-26, 22 Figs, Society Of Exploration Geophysicits, Oklahoma.
Lucia. F., 2007, Carbonate Reservoir Characterization, Springer, Dordrecht Netherlands.
Mathew M., et al., 2020, The Emergence Of Miocene Reefs In South China Sea And Its Resilient Adaptability Under Varying Eustatic, Climatic And Oceanographic Conditions, Scientific Reports, natureresearch.
Mavko, G., Mukerji, T., & Dvorkin, J. ,2009, The Rock Physics Handbook, Cambridge Univ. Press. United States.
Mirshadi A. et al., 2024, Estimation of pore type distribution utilizing petrophysical data and rock physics modeling on an Iranian carbonate reservoir, Journal of Petroleum Exploration and Production Technology (2024) 14:2379–2397. Springer.
Naseer M.T., et al., 2024, Seismic attributes and spectral decomposition-based inverted porosity-constrained simulations for appraisal of shallow-marine lower-Cretaceous sequences of Miano gas field, Southern Pakistan, Heliyon 10 (2024) e25907, Elsevier.
Pangastuti, N. P. J. A. R., Rosid, M. S., & Wijanarko, E. (2025). Binio Formation Characterisation Using Seismic Acoustic Impedance Inversion in the Lotus Field of the Central Sumatra Basin. Scientific Contributions Oil and Gas, 48(2), 95-110. https://doi.org/10.29017/scog.v48i2.1692
Pramudito D., et al., 2021, Enhancing Low-Frequency Model for Post-Stack Inversion using Geostatistics: A Case Study in Imaging Carbonate Structure, Jurnal Geofisika (2021) Vol. 19, No. 02 pp. 69-73, HAGI.
Rider, M., 1996, The Geological Interpretation of Well Logs, Rider-French Consulting Ltd, Scotland.
Sukma, R. F. N., Rosid, M. S., & Wijanarko, E. (2025). Telisa Formation Characterization Using Seismic Acoustic Impedance Inversion in the Akasia Area of the Central Sumatra Basin. Scientific Contributions Oil and Gas, 48(2), 29-40. https://doi.org/10.29017/scog.v48i2.1774
Russell. B., 1988, Introduction to Seismic Inversion Methods, Society Of Exploration Geophysicits, Oklahoma.
Salvini S., et al., 2023, Exploring the pore system of carbonate rocks through a multi analytical approach, Environmental Earth Sciences (2023) 82:564, Springer.
Schlumberger, 2016, Basic Well Log Interpretation. The Defining Series:.
Serra. O., 2003, Well Logging and Reservoir Evaluation, Technip, Paris.
Sheriff. R. & Geldart. L., 1995, Exploration Seismology, Cambridge Univ. Press. United States.
Su. Zhaodong., et al., 2023, Seismic prediction of porosity in tight reservoirs based on transformer, Frontiers in Earth Science. Frontiers.
Taqiy, Z. F., Utomo, W., Shidqii, M., & Susilo, A. (2025). Karakterisasi Reservoar Berdasarkan Analisis Inversi Seismik Impedansi Akustik dan Multiatribut Seismik, Studi Kasus: Lapangan Bunyu Tapa, Cekungan Tarakan, Kalimantan Utara. Lembaran publikasi minyak dan gas bumi, 59(3), 17-50. https://doi.org/10.29017/LPMGB.59.3.1891
Wadas S.H. & Hartmann H. V., 2022, Porosity estimation of a geothermal carbonate reservoir in the German Molasse Basin based on seismic amplitude inversion, Geothermal Energy 10:13.
Wang. Zi-Zhen., et al., 2021, Empirical rock physics relationships on carbonate dry frame elastic properties, Petroleum Science (2021) 18:783–806, Springer.
Weger. R. et all., 2009, Quantification of pore structure and its effect on sonic velocity and permeability in carbonates, AAPG Bulletin, v. 93, no. 10, The American Association of Petroleum Geologist, Oklahoma.
Wibowo. Rahmat Catur., et al., 2023, Analysis of Unconventional Oil and Gas Reservoirs using Well Logging, Geochemical and Seismic Data, Jurnal Geocelebes Vol. 7 No. 2. Departement of Geophysics Hasanuddin University. Makasar.
Wilson. M.E.J., 2011, SEAsian carbonates: tools for evaluating environmental and climatic change in equatorial tropics over the last 50 million years, Geological Society London Special Publications 2011, p344-372, The Geological Society of London, London.
Xu. Guoqiang & Haq B.U., et al., 2022, Seismic facies analysis: Past, present and future, Earth-Science Reviews Volume 224, January 2022, 103876. Elsevier.
Yang. Zhen., et al., 2024, Types and Evolution of the Miocene Reefs Based on Seismic Data in the Beikang Basin, South China Sea, Journal of Marine and Engineering 12,360, MDPI, Switzerland.
Zulivandama, S.R., Hermansyah, G.M. & Wijaksono, E., 2018, Aplikasi Metode Sweetness dan Spectral Decomposition untuk Identifikasi Awal Potensi Hidrokarbon di Perairan Utara Bali. Jurnal Geologi Kelautan.
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