After surveying 54 energy companies, the federal agency reported that 86 rigs and production platforms remained evacuated and switched off.

This accounts for a loss of 842,091 barrels of oil, 56.14% of the region’s average daily production of 1.5 million barrels. About 35% of shut-in oil was as a result of problems with onshore infrastructure.

The evacuations have also shut in 3.4 billion cubic feet of natural gas – or 34.1% of the normal 10 billion cubic feet per day.

In total, the production of 18.6 million barrels of oil and 91.1 billion cubic feet of gas have been delayed, since Katrina first forced platforms to evacuate over a fortnight ago.

Meanwhile, Louisiana's Department of Natural Resources has said the estimated daily loss in royalty income was near $900,000, as about 2640 oil and gas wells remained blocked.

A DNR spokesperson reported that refineries in Louisiana suffered varying degrees of damage, from minimal to heavy, but only three remained closed.

"I have seen some of the disruption, some of the damage to our coast, but it is just still too early to gauge realistic impacts to our resources from Katrina," the spokesperson said in a press release.

The Louisiana Independent Oil and Gas Association said this week that the offshore support structure in Venice at the mouth of the Mississippi River was heavily damaged, but Port Fourchon - a major oil and gas exploration hub almost 100km south of New Orleans - should be 75 to 90% operational by the end of the week.

http://www.mms.gov/