Gulf oil leak may be 5 times worse

Theoffshore oil well at the site of a drilling-platform disasterin the Gulf ofMexico is leaking five times more petroleum than previously thought into the sea, U.S. Coast Guard officials said late Wednesday night.

"It's premature to say this is catastrophic. I will say this is very serious," Rear Adm. Mary Landry said.

A second leak in the well was discovered Wednesday, andscientists from theU.S. National Oceanic Atmospheric Administrationnow believe that 5,000 barrels a day of oil, up from 1,000 a day,is pouring into the Gulf.

An official atBP, the petroleum conglomerate that operated the rig, saidhethinks the new leak hasn't increase theflow rate.Doug Suttle, the company's chief operating officer, held to the 1,000-barrel-a-day figure in a news conference Wednesday night, as Landry stuck to the NOAA estimate.

The Deepwater Horizon oil platform, located about 80 kilometres off the Louisiana coast,exploded April 20, sending giant fireballs into the sky as it went up in flames. A total of 126 workers were aboard at the time; 11 are missing and presumed dead.

The rig collapsed into the Gulf last Thursday, rupturing the platform's wellhead 1,500 metres below the water's surface, sending oil gushing into the water.

As ofWednesday midday, the resulting oil slickmeasured 160km by 72 km and was creeping toward the Louisiana shore, threatening an environmental disaster.

Thousands of litres burned

Mere hours before the latest announcement about the second leak, the coast guard had starteda testburnof some of theoil.

The coast guard used a 152-metre boom to corral thousands of litres of thick petroleum at the surface, tow it away from the coastline and set it on fire for an hour.

Petty Officer Thomas Blue said burning the oil is better than letting it reach ecologically sensitive areas on the shore.

"They don't go out and light the entire oil sheen on fire,"Blue said before the burn began. "In the past these burns have burned about 90 per cent of the oil, and they've found that thisisbetter for the environment," he said.

Wednesday's burn began in the lateafternoon, withofficials setting fire with hand-held flares to a test area about 50 kilometres east of the Mississippi River delta. The test was deemed a success, but the coast guard didn'tstart any new burns before nightfall.

Greg Pollock, head of the oil spill division of the Texas General Land Office, said the burning method is effective.

The oil has the consistency of thick roofing tar and when the flames die off, Pollock said, the material that is left resembles a ball of hardenedtar that can be removed from the water with nets or skimmers.

"I would say there is little threat to the environment because it won't coat an animal. And because all the volatiles have been consumed, if it gets on a shore it can be simply picked up," he said.

Crews have been trying with submersible robots to activate a shut-off devicein the well, but those attempts have been unsuccessful.

In another development, BP said work could begin Thursday to drill a relief well to alleviate pressure in the blown-out well, but the processcould take months.

BPsaid cleanup costs are running at $6 million US a day, and it could require $100 million US to drill a relief well. The total cleanup could cost around $1 billion US.