(FORTUNE Magazine) – Expect the biggest business story of the summer--oil prices--to carry on well into the fall. OPEC meets in Vienna on Sept. 15, and traders around the world will be looking for any signs the cartel is making good on its earlier vows to increase production in the face of $44-a-barrel crude. Oppenheimer analyst Fadel Gheit thinks Saudi Arabia in particular will be inclined to open the taps further as a way to bolster Bush's reelection hopes. Demand should start to cool off too. September and October are among the weakest in terms of crude consumption, when the summer driving season has come to a close but heating-oil demand hasn't yet picked up. As for the markets, the rampant speculation that characterized trading late this summer (crude futures hit new records in 14 out of 15 trading days in mid-August) has been dampened by tighter margin requirements on trades, which were implemented in late August by the New York Mercantile Exchange. Meanwhile the Kremlin's battle with Yukos Oil is edging toward a conclusion, which should eventually reassure the markets. (For more on Yukos, see "Russia's Trial of the Century.") All this makes it likely that oil prices will drop by 15% over the next month, says Gheit. "Barring a cold winter," he adds, "prices will be at least $10 lower by next spring." That would be welcome news for U.S. households--and for the White House. --Nelson D. Schwartz