83 days after it started, OIL caps Assam gas well blow out in third attempt
The natural gas well in Assam’s Tinsukia district had a blowout during a workover or maintenance operation to locate a new reservoir on May 27.Updated: Aug 17, 2020, 22:57 IST
The blowout --- an uncontrolled release of gas or oil -- at an Oil India Limited (OIL) natural gas well in Upper Assam’s Baghjan was capped on Monday after 83 days.
Efforts are in progress to douse the fire, which had broken out on June 9, at the well.
The natural gas well in Assam’s Tinsukia district had a blowout during a workover or maintenance operation to locate a new reservoir on May 27.
While efforts were underway to plug the blowout, the well caught fire on June 9, which claimed two firefighters’ lives.
The blaze is yet to be brought under control.
“The well-capping operation was initiated on Monday morning and the capping blowout preventer (BOP) stack was successfully placed over the wellhead. The 16 studs have also been tightened,” OIL said in a statement.
The BOP is a specialised valve or a similar device, which is used to seal control and monitor oil and natural gas wells to prevent blowouts.
Usually, they are installed in stacks of other valves.
“The preparations for killing operation are on. The BOP and the lines connected to it are being kept cool through continuous spraying of water,” the statement added.
Installation of the BOP stack was the penultimate task needed to complete the operation.
Once the BOP is installed, the process of “killing the well” and dousing the fire starts.
The mechanism requires injecting a “kill fluid”, a sludge-like specially prepared mud, into the well slowly to push the gas from it back to the reservoir.
The well at Baghjan is around 3.5 kilometres deep and the killing operation that will douse the fire is expected to take up to 36 hours.
Monday’s attempt at placing the BOP on the wellhead was the third try after OIL personnel and foreign experts engaged for the job had failed twice earlier.
On July 31, experts were attempting to place the BOP stack, weighing nearly 3 tonnes, on the wellhead, when the Athey Wagon, a type of hydraulic lift used to fight oil-field fires consisting of a track-mounted boom with a hook in one end, fell down.
Another attempt to cap the blowout failed on August 10 after one of the two bull lines connected to the Athey Wagon, which was lifting the BOP stack, came out from the socket due to the impact of excessive heat.
Initially, OIL authorities had said that the well would be plugged in a month, but later the deadline was extended to July 7.
However, several delays occurred due to annual flood woes, technical glitches and three foreign experts also sustained burn injuries while attempting to douse the flames.
Fears abounded regarding environmental damage due to the blowout and the blaze to the surroundings of the gas well, which is located adjacent to Dibru Saikhowa National Park (DSNP) and the ecologically-sensitive Maguri Motapung wetland.
Several studies by different agencies are in progress to measure the extent of the damage.
In June, the National Green Tribunal (NGT) authorities had ordered the formation of an expert committee to probe the blowout and subsequent fire and assess the damage caused to human lives, wildlife, and the environment because of industrial disasters.