What is happening?
As you might already know, the Brahmaputra is flooding in Assam and putting a lot of lives at stake with almost 56 lakh people affected and over 100 people dead. However, this isn’t about that. This is about something happening in the far east border of the state, near a city called Baghjan.
Baghjan is the site of a natural gas field under operation of OIL (Oil India Limited) - yes the wordplay is evident. This is the excavation spot where natural gas from the mines deep below has been burning since 9th June, 2020. This phenomenon is termed as a blowout and typically take months to die down on its own.
What is a blowout?
Natural gas wells are deep in the crust and are under intense pressure due to this depth. This leads to a magnanimous pressure gradient when the well is dug and the gas comes in direct contact with the atmosphere. This leads to gas release at terminal velocity and leads to kicks (or pressure changes). These kicks, when not controlled in time, can ignite the gas and cause massive fires in the well and at the excavation site.
Why did the blowout happen and is it being controlled?
Possible reasons behind blowouts range from simple lack of attention, poor workmanship, bad maintenance, old age, sabotage to morpho-tectonic factors. A device called a blowout preventer is usually installed in wells.
The gas well at Baghjan was being serviced, and a new sand was being tested at another depth in the same well. The blowout preventer was also removed and suddenly, gas started to ooze out of the exposed well.
Controlling a blowout presents its own set of challenges. The control of a blowout depends on two things: the size of the reservoir and the pressure at which the gas/oil is flowing out. While many blowouts automatically collapse on their own, it can take up to months. To control a blowout, the first step is to pump in water, so that the gas does not catch fire. This reservoir was particularly difficult to control since it was a gas well and ran the risk of catching fire at any point.
However, OIL has begun working towards improving the situation of the disaster. Bioremediation of sludge is being done using a technology developed in-house by OIL’s research and development wing. Bioremediation is the cleaning of polluted sites through naturally occurring or introduced microorganisms for breaking down environmental pollutants. OIL also updated the efforts to kill the well fire before capping the blowout. Certain steps such as the erection of a heat shield have been completed.
Is it a big deal though?
It is near the border region of our country and may not be of enough significance to us. However, it is important to note that just one kilometre from the field is Maguri-Motapung wetlands, an ecotourism site. The State-owned sanctuary Dibru Saikhowa National Park - renowned for migratory birds - is about 2.5km (1.5 miles) away. Dibru-Saikhowa is also a Biosphere Reserve situated on the south bank of the river Brahmaputra in Assam. It is easy to understand that this amount of fossil fuel burning (regardless that natural gas is the cleanest bi-product) is very harmful to the entire biodiversity of the regions and will have negative impacts. Reports have already surfaced about the death of a river dolphin due to the toxins being released.
How was drilling near an ecologically sensitive zone permitted?
OIL India said that it had obtained permission for the seven wells in 2016 on the basis of the sophisticated ERD [extended reach drilling] technology.
The Extended Reach Drilling Technology was extensively used to intersect hydrocarbon targets far from the surface or areas of the reservoir that otherwise were difficult to access.
This technology enabled drilling of wells up to a depth of approximately 4 km from an existing well plinth without entering the protected area. Hence, this technique ensured sanctity of the protected area while providing for safe drilling
According to OIL India, the permissions were obtained as the location of the drilling site was completely outside of the protected area. It must also be noted that the demarcation for a protection area includes a buffer zone to create a safety bubble.
What actions are being taken wrt to the incident?
The National Green Tribunal (NGT) has directed the Environment Ministry, Oil India Limited (OIL) and two other entities (Assam State Pollution Control Board and the Assam State Biodiversity Board) to explain how the proposed drilling of seven oil wells in Dibru-Saikhowa National Park was permitted.
Following this directive, a committee formed by the NGT has noted that there was a mismatch between planning and execution by OIL, leading to a well blowout in eastern Assam’s Baghjan. Further details and progress is awaited as of date of publishing.