MICROSEISMIC MONITORING ANALYSIS BEFORE, DURING, AND AFTER OVERHAUL IN PATUHA GEOTHERMAL FIELD
Production and fluid injection activities in geothermal fields can disrupt the stability of the subsurface geological structure. This disturbance often results in the occurrence of microseismic events. Monitoring microseismic activity provides valuable information about reservoir behavior, such a...
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| Format: | Final Project |
| Language: | Indonesia |
| Online Access: | https://digilib.itb.ac.id/gdl/view/84795 |
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| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | Production and fluid injection activities in geothermal fields can disrupt the stability of the
subsurface geological structure. This disturbance often results in the occurrence of
microseismic events. Monitoring microseismic activity provides valuable information
about reservoir behavior, such as crack propagation and fluid movement, and plays a
crucial role in disaster mitigation within geothermal industrial areas. In this study, we
utilized microseismic data acquired from 11 recording stations in the Patuha geothermal
field over three months (December 18, 2023 – March 27, 2024), with data downloaded in
stages, covering periods before, during, and after the overhaul. Overhaul refers to the
temporary cessation of production and fluid injection in wells. The identified microseismic
events underwent P- and S-wave arrival time picking, resulting in 125 identified
microseismic events with a Vp/Vs ratio of approximately 1.70. The next step involved
determining the hypocenter locations using a non-linear method, followed by hypocenter
relocation using the double-difference method. The relocation results showed that the
travel time residuals were closer to zero compared to the pre-relocation stage. Postrelocation analysis revealed a main cluster in the Ciwidey Crater reservoir area, which
also contains an upflow zone. The distribution trend of microseismic hypocenters across
all time periods (before, during, and after overhaul) was observed to be concentrated in
the Ciwidey Crater reservoir, with the highest increase in seismicity occurring during the
overhaul period. This increase is associated with the destabilization of the subsurface in
the reservoir area during the overhaul process, which triggered microseismic events along
the geological faults in the study area. |
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