From EnergyDaily
...Greatly weakened from that overland journey, Dean moved across the Bay of Campeche in the southern Gulf of Mexico, home to more than 100 oil platforms, three major oil exporting ports and the Cantarell oil field, Mexico's most productive.
The entire field's operations were shut down just ahead of the storm, reducing daily production by 2.7 million barrels of oil and 2.6 billion cubic feet of natural gas.
From the Washington Post