Evaluation of thermal maturity of source rock based on geochemical method, a case study of Late Oligocene source rock in Hoa Tra field, Cuu Long basin, Vietnam

  • Affiliations:

    1 PetroVietnam University, Baria-Vungtau, Vietnam
    2 Hanoi University of Mining and Geology, Hanoi, Vietnam

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  • Received: 9th-Dec-2023
  • Revised: 17th-Mar-2024
  • Accepted: 26th-July-2024
  • Online: 1st-Aug-2024
Pages: 67 - 78
Views: 637
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Abstract:

The  Hoa Tra field is located in the southeast of the Cuu Long basin which has great potential for oil and gas. The source rocks in this area are mainly fine-grained sediments from the late Oligocene and early Miocene, which are located in a continuous deposition zone and under anaerobic conditions. This paper focuses on studying the maturity level of late Oligocene source rock through geochemical analysis methods. Specifically, the paper uses indicators such as T­, Ro, MPI-1, Ts/(Ts+Tm) and C29 steran 20S/(20S+20R) from Rock-Eval Pyrolysis, Vitrinite reflectance and Gas chromatography-Mass spectrometry methods, respectively, to evaluate the level of thermal maturity of the source rock. The source rocks in the Hoa Tra field mainly contain types I and II, which are poor in vitrinite particles, leading to low Ro measurement results. However, when Ro is calculated from Tmax and (MPI-1), it indicates that the thermal maturity of source rock from the upper part of the late Oligocene is in the early mature stage (Ro avg= 0.56%), while those from the lower part of late Oligocene are mature and in the phase of oil generation (Ro avg= 0.65%). These results are similar to those obtained from assessing thermal maturity using Ts/(Ts+Tm and C29 20S/(20S+20R) indicator (the average values for the respective parameters are 0.32 and 0.31 for the upper part, while those are 0.39 and 0.42 for the lower part of late Oligocene). The article also shows that the contribution to the  Hoa Tra field is not only from in-situ generated oil but also from migratory oil coming from nearby troughs.

How to Cite
Tran, O.Thi, Pham, N.Bao, Nguyen, H.Minh Thi, Do, L.Thuy Thi, Nguyen, M.Duy and Bui, N.Thi 2024. Evaluation of thermal maturity of source rock based on geochemical method, a case study of Late Oligocene source rock in Hoa Tra field, Cuu Long basin, Vietnam. Journal of Mining and Earth Sciences. 65, 4 (Aug, 2024), 67-78. DOI:https://doi.org/10.46326/JMES.2024.65(4).07.
References

Abdula, R. A. (2017). Source rock assessment of Naokelekan formation in Iraqi Kurdistan. Journal of Zankoi Sulaimani, 19 (1)- Part A.

Behar F., Beaumont V., Penteado H.L.D.B. (2001). Rock-Eval technology: performances and developments, Oil Gas Sci. Technol. 56 (2001) 111-134.

Dembicki, Jr. H., (2017). Practical Petroleum geochemistry for Exploration and Production. Elsevier, Amsterdam, 330p.

Ma, A., Jin, Z, Zhu. and Bai, Z. (2017). Cracking and thermal maturity of Ordovician oils from Tahe Oilfiems, Tarim basin, NW China. Journal of Natural gas Geoscience, 1-14.

Millayanti, A., Aprianto, A. R., Fauzan, R. F. and Anggara, M. U. (2019, March). Evaluation of Organic Matters, Hydrocarbon Potential and Thermal Maturity of Source Rocks Based on Geochemical and Statistical Methods: Case Study Miocene of the Seblat and Lemau Formation, Bengkulu Basin. In IOP Conference Series: Earth and Environmental Science (Vol. 248, No. 1, p. 012075). IOP Publishing.

Nguyen, D. C., Mai, T. T., Tran, V. X. and Tran, N. H. (2019). Oligocene combination/ stratigraphic traps and their reservoir quality in CuuLong basin, offshore Vietnam. Petrovietnam Journal, 6, 30-40.

Peters, K. E ., Walters, C. C . and Moldowan, J. M (2005). The Biomaker Guide (Vol. 2). Biomarkers and Isotopes in Petroleum Exploration and Earth History. Cambridge University Press, New York, 702 p.

Peters, K. E. and Cassa, M. R. (1994). Applied Source-Rock Geochemistry. In: Magoon, L.B. and Dow, W.G., Eds., The Petroleum System. From Source to Trap, American Association of Petroleum Geologists, Tulsa, 93-120.

Pham, H. G., and Vu, T. H. Q. (2019). Geochemical evaluation of shale formation in northern Song Hong basin, Vietnam. Journal of Petroleum Exploration and Production Technology, (9)1839-1853.

Radke, M. (1988). Application of Aromatic Compounds as Maturity Indicators Insource Rocks and Crude Oils. Marine and Petroleum Geology, 5, 224-236.

Radke, M. and Wetle, D. H. (1983). Advance in organic geochemistry (section: The methylphenanthrene index (MPI). A maturity parameter based on aromatic hydrocarbons). John Wiley and Sons, New York, 800p.

Tissot, B. P. and Welte, D. H. (1984). Petroleum Formation and Occurrence. 2nd Edition. Springer-Verlag, Berlin, 699 p.

Tran, L. D and Phung, D. H. (2007). Cuu Long basin and petroleum resource. The petroleum geology and resources of Vietnam. Science and Technics Pub House, 551p.

VRJ Petroleum Company (2006). Report on phase 1 of Exploration period, block A Offshore Vietnam.

VSP (2014). Geochemical analysis report of the HT-2X well, block A.

VSP (2016a). Caculate the reserves of oil and gas,  Hoa Tra field, block A, Cuu Long basin.

VSP (2016b). Geochemical analysis report of the HT-3X and HT-4X well, block A.

VSP (2018). Geochemical analysis report of the HT-5X well, block A.

VSP (2019). Geochemical analysis report of the HT-6X, block A.

Walters, C. C., Peters, K. E. and Lillis, P.G. (2012). Analyzing the Thermal History of Sedimentary Basins: Methods and Case Histories. (chappter: Molecular Indicators of Geothermal history, pp. 17-28). SEPM Society for Sedimentary Geology, Tulsa, 219p.

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