PRELIMINARY STUDY OF GROUND-PENETRATING RADAR FOR STEAM VENT AND FRACTURE IDENTIFICATION AROUND THE WELL PAD OF "TSC" GEOTHERMAL FIELD

• Main Author: Sheilla Chrisnawan, Talitha
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/44001
• Institution: Institut Teknologi Bandung

Ground Penetrating Radar (GPR) surveys were conducted in well pad 4 of "TSC" Geothermal field where a well leakage was detected. A landslide few years ago caused the leakage and also formed a fumarole thermal manifestation as seen on the surface. Leakage and fumarole are dangerous as they are indicating that new steam vent is forming, which can affect the ground stability. Anticipation and mitigation were done through mapping of subsurface steam vent and fracture to analyze their directionality. Profilings were done on 9 lines using MALA Unshielded Antenna 50 MHz, CMP measurement was done in one point resulted in 2 layers with 0,14 m/ns and 0,16 m/ns in velocity. Profiling datas were processed using REFLEXW by filtering such as gain, bandpass filter, fk-filter, and deconvolution. Other than field data, pemodelan kedepan using FDTD technique in MatGPR program was made to help in interpretation. Pemodelan kedepan showed that dipping fracture with almost 90o angle formed more diffractions than flat fractures. Field data processing showed areas with low-amplitudo reflection as indicator of steam that migrates through fracture or vent.