Passive Seismic Survey Project
Seismotech was awarded the second phase of a passive seismic survey in Assam-Arunanchal Pradesh, in NE India. The area of interest is characterized by very difficult accessibility conditions, due to rainforests or rivers. The exploration areas are also environmentally sensitive because of the wildlife presence.
The data acquisition period for the second phase of the PST survey was commenced in 14th of November 2021 and completed in July 2022. Two seismic networks were installed in different blocks and a number of peripheral stations were placed in order to control the seismicity more effectively (272 3C seismic stations, in total). The flooding effects in Vrahmaputra riverbanks due to monsoons were absent and Covid-19 situations were improved, so the acquisition procedure was completed without problems.
The scope of the project was to define the seismicity of the area of interest, the tectonic characteristics based on focal mechanisms, and stress variation estimations. Moreover, 3D Vp and Vp/Vs models were estimated, providing valuable structural and lithological information that can benefit oil exploration program in Assam-Arunanchal Blocks.
The tomographic results of phase-I were very promising. The processing results of phase-II provided robust and more detailed 3D imaging of the areas of interest.