The raging flames, which were visible from 30 kilometres away, at the Tengratila gas field in eastern Chhatak will take no less than a month to extinguish.

Operators of the Canadian oil company Niko ran into trouble when a sudden surge in natural gas pressure at the well was noticed on Friday at 7:30pm.

They desperately tried to tackle what they considered an impending disaster by diverting the rising pressure of gas to 500 meters away with a pipeline and burning it off. The operators claimed to the press on Friday night that the "major threat is over."

But the drilling well exploded at 5:00am yesterday with such a loud noise that was heard from areas 8km off the location. The raging fire devoured the expensive drilling rig, cracked the soil of the area and burnt down 40 houses.

A Petrobangla expert, after visiting the site of devastation, pointed fingers yesterday at the sloppy handling of well by Niko.

He alleged that it was the result of 'inadequate monitoring' of exploration activities and of drilling too deep into the gas field without adequate structures.

"This was a repeat of the 1999 Magurchhara explosion," he said.

Experts say the inferno will take 30-45 days to control unless the gas from this well, estimated to have a 300 billion cubic feet reserve, burns itself out.

State Minister for Energy AKM Mosharraf Hossain, along with secretary in charge of the ministry Nazrul Islam, Petrobangla Chairman SR Osmani and Petrobangla Director (operation) Raihanul Abedin yesterday visited the spot.

The state minister indicated the inferno will burn 30 to 40 million cubic feet of gas a day-- worth about Tk 30 to 40 lakh.

A Petrobangla expert noticed monitoring flaws at the site.

"Like the Magurchhara incident, there was no monitoring of the exploration activities here. We know many gas structures in Sylhet are volatile and not all foreign operators are as well-informed about these structures as we are," he said.

"The Tengratila field also gave a shallow kick of gas pressure that was experienced at Magurchhara. This is the sign of volatility, which the Niko's drilling operators failed to pay proper attention to.

"But the biggest fault of Niko is that like Occidental, which in Magurchhara had drilled through an improper well casing (made of concrete), Niko also made a casing of 300 metres but went on drilling up to 800 metres without any stable structure," the expert pointed out.

But Niko's Operations Manager Peter Mercier insisted that it was not possible to know the cause of the explosion at the moment. "The incident may have taken place due to the high pressure of the well head. We will have to wait till the fire goes out automatically," he told The Daily Star at a spot two kilometres off the burning gas field.

"We had a target of drilling 1,700 metres. But the disaster occurred after drilling about 800 metres on Friday night. We had tried to avert the accident by firing a flare line within an hour of the abnormal behaviour of the well," he said.

The state minister for energy said they will form an enquiry committee after returning to Dhaka. He declined to comment on the reasons for the explosion, saying: "I would not comment before the committee reaches its own conclusions."

Niko is now trying to mobilise a drilling-rig, owned by Barker, to bring the fire under control. But it will take a few weeks to bring the rig, which was used in Bangura under Block 9, from Chittagong Port.

Experts from abroad are also coming to assist in this emergency operation, according to the Petrobangla chairman.

However, the Niko operations manager was unable to give any details of when the company will be able to start remedial measures. "After the situation comes under total control, we will start work for drilling a relief well for linking with lower zones of the main well. It would be about 500 metres off the main well," Mercier said.

Thirty-seven engineers, technicians and workers, including 22 foreigners, were working on the gas field before the fire took place. Foreigners have now been shifted to safer places.

The Bangladesh Rifles from the nearby outposts along with the police have been deployed two kilometres away from the gas field.

In a further twist, it is alleged that the gas field itself was arbitrarily given to Niko in October 2003 violating government rules.

Niko, which committed to invest $15 million in the field, had deployed a drilling company which is represented by a top leader of a certain bhaban. It is alleged that this person had earlier forced Petrobangla to award it this gas field area along with two other gas fields in Feni and Kamta through a joint venture with Bapex.

Once considered by Petrobangla unsuitable for gas exploration, Niko is the only foreign oil company to operate in Bangladesh without any Production Sharing Contract (PSC).

Niko was given this field despite it having been ring-fenced for future operations by Petrobangla, and US company Unocal had the first right to get exploration right as it operated in that area. The oil company was disqualified by Petrobangla's evaluation in the second round block bidding in 1997.

Though Bapex is 40 percent stakeholder in this venture, none of its staff was at the location, sources said.

There was also no Petrobangla representation to oversee the operations at this gas field even after the Magurchhara experience and with the gas fields in Sylhet showing a tendency to show sudden pressures.

The US company Occidental was found responsible for the Magurchhara explosion, but the company was allowed to sell out its concerns to Unocal and leave Bangladesh in 1999 following an extension of its PSC through a supplementary contract.

Petrobangla demanded $685 million in compensation for damages from Unocal in 2002, but Unocal so far has not paid anything. Instead the company claimed that the compensation has been "paid" through the supplementary contract. As per Petrobangla estimate, the field had a gas reserve of over 245 billion cubic feet.