ONGC reports major progress in controlling Assam gas well blowout

State-owned Oil and Natural Gas Corporation (ONGC) on Saturday said it has made "significant" headway in controlling the gas blowout at the Assam well, with flow rates reducing substantially.

The blowout -- or uncontrolled flow of natural gas -- took place on June 12 at a well of the Rudrasagar oil field of ONGC at Barichuk. A private firm, S K Petro Services, was operating the well on behalf of the company.

In a statement, ONGC said it "has made significant headway in its well control operations at RDS#147A, with the flow rate of gas having reduced substantially, marking a critical step forward in containment efforts."  The international expert team from CUDD Pressure Control, USA, who arrived on site on Friday, has conducted a preliminary assessment of the situation and reviewed all actions undertaken by ONGC teams so far.

"The experts have expressed their agreement with the strategy and execution carried out to date, reaffirming the effectiveness of ONGC's approach to safely managing the well," the statement said without giving a timeframe by when the blowout will be fully controlled.

ONGC said based on the forward plan jointly developed, extensive site preparations are underway to facilitate the next phase of action. The process of removing tubulars from the well has commenced, and mobilisation of cranes for the removal of tubing from the rig floor is in progress.

"Water blanketing continues around the clock as a key safety measure. Additionally, flood-level monitoring of the nearby Dikhow River remains ongoing, ensuring all operations are aligned with environmental and safety protocols," the statement said.

"ONGC is continuously monitoring the low explosive limit (LEL) levels of air around the well site through real-time gas detectors to ensure safety. Medical assistance is being provided at the relief camp to support all those in need."  In a LinkedIn post, Oil Minister Hardeep Singh Puri on Friday said he has been reviewing the well control operation at the RDS 147 A at Sivasagar in Assam.

"The Crisis Management Team headed by experienced Blow Out Control specialists are on the job."  Residents in the vicinity had been relocated to a safe relief camp and arrangements for food, security and other essentials are being arranged by authorities concerned, he said, adding that the well is continuously blanketed by water to avoid fire as a safety measure.

"Composition of gas is found to be free from H2S, CO, and CO2. Being 97 per cent methane which is much lighter than air, it keeps going higher and higher. The gases are getting dispersed into heights and not settling on ground," Puri said.

He added that the air quality around the well site was being monitored continuously and was found to be in safe limits just at 50-100 metres distance from the well mouth.

"Considering the falling gas pressure which has fallen from 2600 psi to 500 psi, we are trying to contain the situation through junk shot operation and will try pumping kill fluids today. If it doesn't suffice and the fire is still not contained, capping of the well shall also be considered," he added.