KARAKTERISASI DAN IDENTIFIKASI ZONA PENYEBARAN MINERAL ASAM PADA SUMUR PAD 9 DI LAPANGAN PANAS BUMI PATUHA, JAWA BARAT

CHARACTERIZATION AND SPATIAL DISTRIBUTION OF ACIDIC MINERALS BASED ON PAD 9 WELL IN THE PATUHA GEOTHERMAL FIELD, WEST JAVA

Authors

  • Muhammad Kurniawan Agung Aristo Institut Teknologi Bandung Author
  • Suryantini Author
  • Idham Andri Kurniawan Author
  • Ezidin Reski Author
  • Randy Wijaya Atmaja Author

DOI:

https://doi.org/10.47599/bsdg.v20i2.554

Abstract

Since 2021, PT Geo Dipa Energi has drilled a total of 19 exploration wells to support the development of Patuha Unit-2. Several of these wells are located approximately 1 km from Kawah Putih, an acid vapor core chimney with a pH of less than 2, which has the potential to produce virulent fluids that contribute to the formation of acid-alteration minerals in the wells. This study aims to identify the presence of acid-type minerals, characterize these minerals, estimate their distribution zones, and interpret the formation processes based on data from wells 9-V2 and 9-Z2. The methods employed include modifications to the latest volcanostratigraphic map, macroscopic, microscopic, and XRD analyses of cutting and core samples from wells 9-V2 and 9-Z2, and mineral alteration characterization encompassing alteration type, pattern, intensity, and paragenesis. Well-to-well correlations were established based on spatial position, depth, hydrology, and volcanostratigraphy. The updated volcanostratigraphic map identifies 12 volcanic units (11 domes and 1 maar), with Kawah Putih representing the youngest unit. Identified acid-type minerals include anhydrite and diaspore. The formation of these minerals occurs through direct precipitation and replacement processes, with moderate to strong alteration intensity. Acid mineral formation is overprinted by later alteration under more neutral pH conditions. In the well group 9, the formation of acid-type minerals is interpreted to result from the lateral mixing of virulent fluids with shallow groundwater. This mixing process is characterized by the presence of calcite and other minerals enriched in Mg.

 

References

Browne, P. (1984). Lectures on Geothermal Geology and Petrology. UNU Geothermal Training Programme, National Energy Authority, Grensasvegur 9, 105 Reykjavik, ICELAND.

Chen, P. (1997). Table of Key Liners in X-ray Powder Diffraction Patterns of Minerals in Clays and Associated Rocks. [Geological Survey Occasional Paper 21]. Department of Natural Resources, Geological Survey.

Harding, T. P. (1973). Newport-Inglewood trend, California—An example of wrenching style of deformation. AAPG Bulletin, 57(1), pp. 97-116.

Hedenquist, J. W., Arribas, A. R. dan Gonzalez-Urien, E. (2000). Exploration for Epithermal Gold Deposits. Society of Economic Geologists, Reviews in Economic Geology, 13, pp. 245–277

Koesmono, M., Kusnama, Suwarna, N. (1996). Peta Geologi Lembar Sindangbarang dan Bandarwaru, Jawa. Bandung. Pusat Penelitian dan Pengembangan Geologi.

Layman, E. B., dan Soemarinda, S. (2003). The Patuha Vapor-Dominated Resource West Java. PROCEEDINGS, Twenty-Eighth Workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, California, January 27 29, 2003 SGP-TR-173.

Pramudityo, D. (2024). Karakterisasi Litologi Berdasarkan Data Pengeboran Sumur Dangkal serta Hubungannya dengan Nilai Resistivitas Geolistrik dan Data Anomali Gas Radon Area G. Patuha Utara. Tesis Program Magister, Institut Teknologi Bandung. Unpublished.

Reski, E. Pamungkas, K.J., Sukarno, D.B., Atmaja, R.W., Samudra, E.D., Ramadhan, Y. (2024). The updates of 2021-2023 Patuha Drilling Campaign: Challenges and Successes in Expanding the Resource Areas. PROCEEDINGS, The 10th Indonesia International Geothermal Convention & Exhibition (IIGCE) 2024.

Reyes, A.G. (2000). Petrology and mineral alteration in hydrothermal systems: From diagenesis to volcanic catastrophes. Institute of Geological and Nuclear Sciences, New Zealand.

Sriwana, T., van Bergen, M. J., Varekampc, J. C., Sumarti, S., Takanod, B., van Ose, B. J. H., and Lengf, M. J. (2000). Geochemistry of the acid Kawah Putih lake, Patuha Volcano, West Java, Indonesia. Journal of Volcanology and Geothermal Research 97 (2000) pp. 77–104.

Utama, P. P., Utami, P., Marliyani, G.I., Atmaja, R.W. (2021). Subsurface Geology and Hydrothermal Alteration of The “X” Geothermal Field, West Java: A Progress Report. Journal of Applied Geology, Vol 6, No 1.

Published

2025-08-31

Issue

Section

Buletin Sumber Daya Geologi