#TITLE_ALTERNATIVE#

• Main Author: USWATUN HASANAH (NIM : 22310013), MIA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/23063
• Institution: Institut Teknologi Bandung

Wayang Windu geothermal field lies between Wayang Mt, Windu Mt and Malabar Mt volcanic zones. This geothermal field starts to produce steam on June 2000 with capacity production of 227 MWe from two unit productions. At MBB-1 well, three schemes of hydraulic stimulation have been carried out, i.e. in 1998, 2005, and 2007. Those experiments are carried out in order to monitor hydraulic fractures that occurred in subsurface, so that the strategy of future exploration and well targeting could be estimated. Around 234 microearthquakes were recorded during 44 days of operation that is conducted near the Malabar complex in 2007. Based on those data, we determine subsurface geological structure and characterization reservoir by implementing attenuation tomographic imaging method. <br /> <br /> <br /> <br /> Attenuation is the physical parameters of rock that can reflect the geological conditions beneath the surface. We conducted attenuation tomographic imaging at Wayang Windu geothermal field by using the MEQ data in the form attenuation operator, t*. We applied a method of spectral fitting to invert the t* value. For the attenuation tomographic inversion, we used the initial 3-D velocity model from the previous study in the region. Our study results show that the value of Qp, Qs and Qp/Qs ratio in the geothermal field is an important parameter for interpreting subsurface structure. We interpreted the joint immaging result of Qp, Qs and Qp/Qs ratio with previous seismic velocities (Vp, Vs and Vp/Vs ratio) tomography result. We can see that the high attenuation value (low Q value) and low velocity anomaly structures may corresponded to fluid filled rock and also fault segment.