The Assam government on Monday asked a group of scientists to study tremors being felt at Baghjan in Tinsukia district, where a gas well caught fire on June 9, and submit a report for it to take appropriate steps to deal with them. The mild temblors have triggered panic in the region, where residents said some houses have also developed cracks.
The Oil India Limited (OIL), which operates the well, has also asked CSIR-North East Institute of Science and Technology (CSIR-NESIT) to study the induced seismicity in the area because of the blowout, or uncontrolled release of gas when pressure systems fail, that began from the well in late May.
Induced seismicity refers to tremors and earthquakes, mostly of low magnitude, which are caused by human activity including oil and gas operations.
Chief minister Sarbananda Sonowal promised the study during a visit to the site along with Union petroleum minister Dharmendra Pradhan on Sunday. He met the scientists from the Indian Institute of Technology-Guwahati (IIT-G) and CSIR-NEIST and commissioned them the study.
Residents of Baghjan and nearby Natun Rongagora village have reported repeated tremors since June 9 when the well caught fire a fortnight after gas and oil condensate began leaking from it following the blowout.
“We started experiencing tremors from Wednesday [last], a day after the well caught fire. ...walls of several houses developed cracks,” said Hiren Senapati, a Natun Rongagora resident.
{{/usCountry}}“We started experiencing tremors from Wednesday [last], a day after the well caught fire. ...walls of several houses developed cracks,” said Hiren Senapati, a Natun Rongagora resident.
{{/usCountry}}“The tremors have been felt intermittently. Nearly 80% of our villagers are staying in relief camps, the rest who were in their homes are scared to live there because of the tremors...”
Nearly 2,000 families, which were evacuated because of the blowout beyond a radius of 1.5 km from the well, were later shifted even further and housed in 12 relief camps because of the fire.
Gauhati University’s geology professor Bhagawat Pran Duarah said since gas and condensate is flowing uncontrollably because of the blowout, such tremors can happen due to sudden release of pressure. “But usually they are not that severe and do not cause any large scale damage.”
CSIR-NEIST director G Narahari Sastry some tremors may have been felt in the area close to the well. “From a scientific point of view, we are very keen to look at what are these tremors and analyse their impact,” he said.
In a statement on Monday, OIL said five broadband seismographs, which are used to detect and record earthquakes, will be deployed by CSIR-NESIT at five sites for data to be recorded for 7-10 days. “Locations have been identified and preliminary civil work for deployment of the instruments is in progress.”
The fire continued to rage at the well amid fears of damage to the eco-sensitive area. OIL last week said it could take about four weeks to control the fire.
The state government on Thursday ordered a probe into the inferno as protests by angry residents over alleged inaction hit crude oil production in the state.
The fire left two firefighters dead while authorities were trying to control the blowout.
The well is located a kilometre from the Dibru Saikhowa National Park. The eco-sensitive Maguri Motapung wetland is just a few hundred metres away from the inferno site.
The blowout has polluted the Lohit river and adjoining wetland and toxic pollutants may have killed fish, insects, as well as pose risk to endangered Gangetic dolphins in the region, a preliminary Wildlife Institute of India survey report said last week.