Reduced activity on the Gulf of Mexico shelf helped drag down GlobalSantaFe's SCORE, or summary of current offshore rig economics, for October. Meanwhile, the U.S. Minerals Management Service (MMS) reports that deepwater Gulf drilling remains strong. The Houston-based offshore drilling contractor's worldwide SCORE decreased 3.1% from September-from 47.8% to 46.3%-led by the Gulf. "While still well ahead of the trough reached in June 1999, the Gulf of Mexico SCORE sank to 34% in October," says chairman and president Bob Rose. The region's SCORE was 40.8% in September. The SCORE in West Africa fell slightly, from 58.2% in September to 57.8% in October. Southeast Asia declined also, from 57.3% to 55.7%. The only region whose SCORE grew was the North Sea, which jumped from 49.4% to 51.7%. By rig type, jackups declined from 58.1% to 53.7%, and semisubmersibles grew from 39.3% to 40.2%. The monthly estimate compares the profitability of current mobile offshore drilling rig dayrates to the profitability of dayrates at the 1980-81 peak of the offshore drilling cycle, when speculative new rig construction was common. In 1980-81, the SCORE averaged 100%. MMS reports that the number of rigs working in the deepwater Gulf of Mexico remained at a peak of 47 in mid-November. These rigs-drilling in more than 1,000 feet of water-are up from 39 working at the beginning of the year. At 1,500 feet, the number of working rigs rose to an all-time high of 43, compared with 32 at the beginning of the year. Unocal Corp. is drilling in a new world-record water depth of 9,727 feet, which eclipses the company's previous record of 9,687 feet on the same prospect, Trident, in Alaminos Canyon Block 903. The Interior Department oil and gas leasing division adds that the total number of deepwater wells drilled in its fiscal-year 2001, which ended September 30, reached a new high of 277 total wells, compared with 226 drilled during the previous fiscal year. -Jodi Wetuski