Massive Fire & Major gas leak in the state of Assam

Since the morning of May 27, natural gas has been continuously flowing out of a gas well in Assam following a blowout or a sudden, uncontrolled release of gas/oil. Meanwhile, people from surrounding villages have been evacuated, while a variety of fish and an endangered Gangetic dolphin have died.

The Baghjan 5 well is a purely gas-producing well in Tinsukia district. It is at an aerial distance of 900 meters from the Dibru-Saikhowa National Park. It was drilled by Oil India Limited (OIL) in 2006. It produces around 80,000 standard cubic meters per day (SCMD) of gas from a depth of 3,870 meters. As per officials, the current discharge is at 90,000 SCMD at a pressure of 4,200 PSI, far higher than the normal producing pressure of around 2,700 PSI.

As, I have previously stated the leak is devastating and its very difficult to control now it appears that fire broke out around the area since control over the well was not successful and it got exploded and reaching to the nearby villages. You can go through about the full details in  my blogs as we get the information but we presently have this amount of information available in the public domain. To get a idea how massive the fire is please go through the video below -

DRILLING OF NATURAL GAS

Like all forms of energy drilling, natural gas drilling starts when a deposit of natural gas is found deep beneath the Earth’s surface. To find these deposits, energy companies use a variety of methods. They look at the surface geology of an area, the seismic energy (how energy moves from inside the Earth to its surface) and even the magnetic properties of the underground rock formations. Once a likely deposit of natural gas is located, the energy company then drills down to reach it.

Assam gas leak: Placement of blow out preventer huge challenge ...


A natural gas well isn’t at all like a water well (where you drill a hole in the ground and water fills it).
Natural gas tends to be contained within the underground rock itself. The rock must be broken to release the gas. And if it’s brought out the wrong way, it can contaminate the groundwater supply surrounding it.  Energy companies send electric charges down the well, which affects the rock around it. After the charges are set off, a highly-pressurized liquid fracking solution is sent down the well. This solution breaks up the rocks, releasing the natural gas. Since the gas is lighter than the fracking solution, it rises to the top of the well for capture. Natural gas is a mix of propane, methane, propylene and other gases.

GAS LEAK
Sometimes, the pressure balance in a well may be disturbed leading to ‘kicks’ or changes in pressure.
If these are not controlled in time, the ‘kicks’ can turn into a sudden blowout. Lack of attention, poor workmanship, bad maintenance, old age, etc.

Poor weather condition hampering work to control gas flow from OIL ...

REASON FOR THE GAS LEAK IN BAGHJAN 5 WELL

The gas well at Baghjan was being serviced, and new sand was being tested at another depth in the same well. To repair the well-head, you need to temporarily ‘kill the well’ or shut down the producing zone.
“The blowout preventer was also removed since we were in the process of repairing the well-head.
But suddenly, gas started to ooze out of the exposed well. Before anyone could do anything, it broke through our cement barrier,” said Tridiv Hazarika, spokesperson of OIL.

COMPARABLE BLOWOUTS IN PAST
OIL-owned oil well in Dikhom (Dibrugarh) in 2005. An ONGC-owned oil well in Rudrasagar in the 1970s. Took three months to contain

 IT SO DIFFICULT TO CONTROL
The control of a blowout depends on two things: Size of the reservoir and the pressure at which the gas/oil is flowing out. This reservoir was particularly difficult to control since it was a gas well and ran the risk of catching fire at any point. To control a blowout, the first step is to pump in water, so that the gas does not catch fire.

IMPACT IN THE SURROUNDING
As many as 1,610 families with 2,500-3,000 people have been evacuated to relief camps. Locals have complained of symptoms such as the burning of eyes, headache, etc. There are reports of deaths of a river dolphin, and a variety of fish. While the well is outside the Eco-Sensitive Zone of the park, The boundary does not matter since the gas is moving through the air. Condensate is falling into Dibru-Saikhowa National Park too. Also close is the Maguri-Motapung wetland an Important Bird Area notified by the Bombay Natural History Society.





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