Lok Sabha Question No. 3026 (UNSTARRED), answered on 2025-03-19
Subject: Scientific Deep Drilling in Koyna-Warna Region
Ministry: EARTH SCIENCES
Asked by: Shri Vishaldada Prakashbapu Patil

## MINISTRY OF EARTH SCIENCES

## GOVERNMENT OF INDIA LOK SABHA

## UNSTARRED QUESTION NO. 3026 TO BE ANSWERED ON WEDNESDAY, 19 TH  MARCH, 2025

## SCIENTIFIC DEEP DRILLING IN KOYNA-WARNA REGION

## 3026.  SHRI VISHALDADA PRAKASHBAPU PATIL:

Will the Minister of EARTH SCIENCES be pleased to state:

- (a) the objectives and expected outcomes of the current mission to drill a 6-kilometer-deep borehole  in  the  Koyna-Warna  region,  particularly  in  understanding  reservoir-triggered seismicity;
- (b) the timeline and budget allocated for the completion of this deep drilling project and the agencies or institutions involved in its execution and research;
- (c) the specific methodologies and technologies being employed in this deep drilling project to study the Earth's crust and seismic activity; and
- (d) the  anticipated  impact  of  this  deep  drilling  project  on  local  communities  and  the environment,  along  with  the  measures  being  taken  to  mitigate  any  potential  adverse effects?

## ANSWER

## THE MINISTER OF STATE (INDEPENDENT CHARGE) FOR MINISTRY OF SCIENCE AND TECHNOLOGY AND EARTH SCIENCES (DR. JITENDRA SINGH)

- (a) The primary objective of the current mission to drill a 6-kilometer-deep borehole in the Koyna  region  is  to  acquire  data  on  pre-seismic  and  post-seismic  changes  in  rock properties in the near field of earthquakes, i.e., at depth of a few km below the surface. Analyses of such datasets and integration with other geological and geophysical data can enhance  our  understanding  of  the  processes  controlling  reservoir-triggered  earthquakes continuing for the past six decades in the Koyna region. The study will also add a new dimension  to  scientific  efforts  aimed  at  improving  the  predictive  capability  of  such earthquakes and contribute to global research on triggered earthquakes.
- (b) The scientific deep-drilling project is being executed in multiple phases. The exploratory phase and the pilot phase have been completed successfully, and several new information have been obtained. The next phase comprising deep drilling to about 6 km depth and setting up of a deep borehole observatory in the Koyna region is highly challenging and is  in  the  detailed  planning  stage.  Accordingly,  necessary  budget will  be  allocated.  The deep drilling is expected to be completed in the next 3-4 years.

The  programme  is  being  implemented  by  the  Ministry  of  Earth  Sciences  -  Borehole Geophysics  Research  Laboratory  (MoES-BGRL),  a  dedicated  centre  established  at Karad, Maharashtra for the purpose. A number of scientific institutions/universities in the country are contributing to the programme by conducting multi-disciplinary investigations and analyses of borehole core samples. MoES also leverages the technical expertise  available  with  the  oil  industry  in  the  country  besides  international  expertise through MoU with International Continental Scientific Deep Drilling Program (ICDP).

- (c) The project employs advanced deep drilling methodologies, including mud rotary and air hammering  techniques, core sampling from target depths, downhole geophysical measurements including high-resolution borehole imaging, advanced laboratory experimentation,  and  borehole  sensor  deployment  including  seismometers,  temperature and  pore  pressure  sensors,  strainmeters,  etc.  These  innovative  technologies  enable detailed study of the  earthquake  generation  processes and  also bring forth  new information about physical and mechanical properties of the Earth's upper crust.
- (d) The  results  emerging  from  the  deep  drilling  project  and  the  associated  local  outreach activities implemented by MoES / BGRL are expected to generate awareness about the science  of  earthquakes,  anticipated  level  of  seismic  activity  and  mitigation  measures among the local communities. No adverse effects are envisaged.

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