Seismicity Analysis and Velocity Structure of Two-phase Geothermal Field in Southern Bandung

Muhamad Firdaus Al Hakim

Abstract


Over a duration of six months, we conducted a microearthquake analysis to characterize the subsurface conditions in the two-phase geothermal field located in Southern Bandung. Throughout the study, a total of 754 microearthquake (MEQ) data were recorded from at least 15 monitoring stations. After selection process of the dataset, 362 events were selected based on their azimuthal gap angle being less than 180°. Initially, the earthquake locations were determined using the Geiger method. Subsequently, we updated the hypocenter locations through simultaneous inversion, incorporating 1D velocity structure and 3D tomographic inversion. Our analysis revealed three primary seismicity clusters, which likely correspond to the injection and production activities within the geothermal field. The southern cluster aligns with the injection wells, extending from a depth of 1 km to 8 km, suggesting that the MEQ events were induced by injection activity. In the production area, a higher concentration of events is observed, densely distributed between depths of 1 km and 3 km. We suspect that the third cluster is associated with the development activity of a steam-dominated geothermal field located east of the main field. Notably, low Vp/Vs values near the surface are detected and exhibit increased thickness towards the north. These characteristics are interpreted as indicative of the steam zone, as the anomaly's location aligns closely with the production area. The thickening of the low Vp/Vs zone towards the north suggests the presence of steam as the impact of fluid extraction in the region, leading to a decline in pressure.

Keywords


TomoDD, MEQ, Geothermal

References


Akbar, A. F., Ryannugroho, R., Jousset, P., Gassner, A., Jaya, M. S., Sule, R., Diningrat, W., Hendryana, A., Kusnadi, Y., Nugraha, A. D., Umar, M., & Indrinanto, Y. (2015). Study on Seismicity and Seismic Tomography on a Hydrothermal System in West Java. World Geothermal Congress 2015, Melbourne, Australia, April, 1–5.

Al Hakim, M. F., Sule, R., & Hendriyana, A. (2019). Seismicity Analysis and Velocity Structure of the Two-Phase Geothermal Field in West Java, Indonesia: Preliminary Result. IOP Conference Series: Earth and Environmental Science, 318(1). https://doi.org/10.1088/1755-1315/318/1/012039

Bogie, I., Kusumah, Y. I., & Wisnandary, M. C. (2008). Overview of the Wayang Windu geothermal field, West Java, Indonesia. Geothermics, 37(3), 347–365. https://doi.org/10.1016/j.geothermics.2008.03.004

Delliansyah, R., Sule, R., & Nugraha, A. D. (2015). Steam and Brine Zones Prediction Inside an Operated Geothermal Reservoir Based on Seismic Velocities Produced by Double Difference Tomography. World Geothermal Congress 2015, April, 1–4.

Ellsworth, W. L. (2013). Injection-Induced Earthquakes. Science, 341(6142), 1225942. https://doi.org/10.1126/science.1225942

Fahrurrozie, A. (2014). Perubahan karakteristik kimia fluida reservoar wayang windu bagian utara sebelum dan setelah produksi tahun 2000 tesis. In Tesis Magister Teknik Panas Bumi. Institut Teknologi Bandung.

Havskov, J., & Ottemöller, L. (2010). Routine Data Processing in Earthquake Seismology. New York: Springer.

Keranen, K. M., Weingarten, M., Abers, G. A., Bekins, B. A., & Ge, S. (2014). Sharp increase in central Oklahoma seismicity since 2008 induced by massive wastewater injection. Science, 345(6195), 448 LP – 451. https://doi.org/10.1126/science.1255802

Kissling, E., Kradolfer, U., & Maurer, H. (1995). Velest user’s guide -. Institute of Geophysics, ETH Zurich, 1(October).

Kusumah, Y. I., & Wibowo, H. H. (2010). Horizontal Derivative from Gravity Data as a Tool for Drilling Target Guide in Wayang Windu Geothermal Field , Indonesia. World Geothermal Congress 2010, Bali Indonesia, April, 25–29.

Majer, E. L., Baria, R., Stark, M., Oates, S., Bommer, J., Smith, B., & Asanuma, H. (2007). Induced seismicity associated with Enhanced Geothermal Systems. Geothermics, 36(3), 185–222. https://doi.org/10.1016/j.geothermics.2007.03.003

McGarr, A. (2014). Maximum magnitude earthquakes induced by fluid injection. AGU: Journal of Geophysical Research, Solid Earth, 119, 3678–3699. https://doi.org/10.1002/2013JB010597

Muchlis, V. A., Sule, R., Nugraha, A. D., Kusnadi, Y., (2015). Reservoir Characterization Based on Hypocenter Location Analysis and 3-D Seismic Velocities. 4. World Geothermal Congress 2015, April, 1–6.

National Academy of Sciences. (2013). Induced seismicity potential in energy technologies. In Induced Seismicity Potential in Energy Technologies. https://doi.org/10.17226/13355

Schmittbuhl, J., Lengliné, O., Cornet, F., Cuenot, N., & Genter, A. (2014). Induced seismicity in EGS reservoir: the creep route. Geothermal Energy, 2(1), 1–13. https://doi.org/10.1186/s40517-014-0014-0

Sherburn, S., Sewell, S. M., Bourguignon, S., Cumming, W., Bannister, S., Bardsley, C., Winick, J., Quinao, J., & Wallis, I. C. (2015). Microseismicity at Rotokawa geothermal field, New Zealand, 2008-2012. Geothermics, 54, 23–34. https://doi.org/10.1016/j.geothermics.2014.11.001

Verdon, J. P. (2012). Microseismic Monitoring and Geomechanical Modelling of CO2 Storage in Subsurface Reservoirs. In Doctoral Thesis. University of Bristol, United Kingdom. https://doi.org/10.1007/978-3-642-25388-1

Wu, Y., Zhao, X. P., Zinno, R. J., Wu, H. Y., Vaidya, V. P., Yang, M., & Qin, J. S. (2016). Chapter 9 - The Application of Microseismic Monitoring in Unconventional Reservoirs. In Unconventional Oil and Gas Resources Handbook. https://doi.org/http://dx.doi.org/10.1016/B978-0-12-802238-2.00009-2

Zhang, H., & Thurber, C. H. (2003). Double-difference tomography: The method and its application to the Hayward Fault, California. Bulletin of the Seismological Society of America, 93(5), 1875–1889. https://doi.org/10.1785/0120020190




DOI: https://doi.org/10.31315/jmtg.v14i1.9950

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