Seismotech applying PST methods in India: An overview.
In 2022, Seismotech successfully completed two challenging PST projects in India!
- A PST survey in West Tripura (NE India), awarded by ONGC. The project started in June 2020 and was successfully completed in June 2022. It was carried out in two phases. During the 1st phase (seismicity assessment), a network consisting of 108 3C seismological stations covered the study area and operated continuously for a period of 3 months. This network was densified (348 stations) during the 2nd phase of the project (HC exploration) and recorded continuously for a period of 8 months. The size of the area of interest was approximately 4,500 km2 and it was characterized by difficult accessibility, hilly terrain and complicated geotectonic regime.
- A PST survey in Assam-Arunanchal Pradesh (NE India), awarded by Oil India. The project started in June 2021 and was successfully completed in October 2022. It was carried out in two phases. During both phases, a dense seismological network consisting of 272 seismological stations was continuously recording for a period of 3 and 8 months, respectively. The survey area consisted of two separate blocks and was characterized by difficult accessibility, due to rainforests or rivers and the presence of wildlife.
Managing to overcome all challenges, we delivered precious information on the subsurface in both cases. These challenges were:
- The two projects were overlapping and data acquisition during the 2nd phase of both projects took place at the same time. So, during a period of 8 months, Seismotech operated simultaneously 620 stations installed in two different areas of NE India (Assam-Arunanchal Pradesh and West Tripura).
- Mobilization for both projects, as well as the 1st phase and the beginning of the 2nd phase of the West Tripura project took place from March 2020 to June 2021, when the global COVID-19 pandemic imposed strict limitations and severe restrictions to all transportations (international, interstate or even intrastate in certain cases), as well as significant delays in any necessary interaction with authorities.
- Operations did not stop during the monsoon period, which affected both survey areas. Especially the areas close to Vrahmaputra river (Assam project) suffered from severe flooding and servicing of the network had to take place by boat.
- Part of both study areas was covered by rainforests, where access was extremely difficult and the installed stations needed to be protected from wildlife.
All these challenges were effectively addressed and both projects ended without problems, managing to illuminate the subsurface below each block of interest.
Results from both surveys were presented in the GEOINDIA 2022 conference, in Jaipur, on October 2022 and were followed by discussions for new PST projects.