Assam Well Blowout: What are the reasons behind the gas leak in Sivasagar? An expert decodes

Assam Well Blowout: The recent natural gas blowout at Oil and Natural Gas Corporation (ONGC’s) Bhatiapar well in Assam’s Sivasagar district has raised several questions about the complexities and risks associated with oil and gas exploration. While such incidents are rare, they underscore the high-pressure challenges intrinsic to the sector and the significance of robust response mechanisms in maintaining operational safety and national energy security.

With gas continuing to leak from an ONGC crude oil well in Assam for the seventh straight day, Chief Minister Himanta Biswa Sarma on June 18 urged Union Petroleum Minister Hardeep Puri to direct the energy major to step up efforts to contain the blowout. In a letter to Puri, Sarma said locals claimed that there has been "inadequate urgency and seriousness in ONGC's response" while trying to contain the leak.

Sarma has also met ONGC Chairman Arun Kumar Singh to review the well control operations following the gas leak.

Expert Decodes

Subrata Borgohain Gogoi, Professor at the Department of Petroleum Technology and Dean of the Faculty of Earth Sciences & Energy at Dibrugarh University, explains the phenomenon of a blowout in relatable terms.

“Oil and gas exploration is like searching for underground treasure. Deep beneath the surface, hydrocarbons accumulate under intense pressure, trapped beneath impermeable rock layers. Drilling into such formations requires meticulous planning, engineering precision, and rigorous safety protocols. However, despite all precautions, there are instances when pressurised gas escapes through a weak point, rushing uncontrollably to the surface, this is what we call a blowout,” said Dr Gogoi.

While blowouts are rare, they are an inherent risk in high-pressure operations, Dr Gogoi said.

“Globally, such events occasionally occur not due to negligence but because of the unpredictable behavior of subsurface formations. Interestingly, a blowout also signals the presence of a productive reservoir which, in the long run, is promising for energy security,” she said.

Memories of the catastrophic 2020 Baghjan blowout

The Sivasagar incident has evoked memories of the catastrophic 2020 Baghjan blowout at Oil India Limited’s site, which lasted over five months and led to significant environmental damage and displacement. Is this incident of a similar magnitude?

“The Sivasagar event involves only natural gas, without any condensate or crude oil release. The reservoir pressure is also relatively low, making the situation more manageable. In contrast, the Baghjan blowout involved high-pressure gas, oil and condensate and ultimately caught fire, escalating the crisis. Importantly, there has been no fire in the current case. The site is being monitored round-the-clock, and ONGC is adhering to international blowout control protocols using certified equipment,” Dr Gogoi explained.

How long to control?

The most pressing question remains – how long will it take to control the blowout?

“It is difficult to estimate a timeframe because each blowout presents unique challenges. The environment is extremely hazardous — even static electricity from clothing can ignite the gas. Every step, whether placing a capping stack or pumping heavy mud to kill the well, must be executed with utmost precision and safety. Additionally, the terrain and monsoon conditions in Assam slow down equipment transport and complicate logistics,” said Dr Gogoi.

Since the blowout on June 12, ONGC has mobilised its top professionals and is also coordinating with international experts, including a specialist from the USA, to ensure swift and safe containment.

(With agency inputs)