FIREFIGHTERS should extinguish Kuwait's last blazing wells in less than a month, but only Iraqi President Saddam Hussein can take the heat off the world oil market.There's enough oil production capacity to get through the cold months, says Cyrus Tahmassebi, chief economist at Ashland Oil Inc. But that could change, he and other analysts warn, if unusually severe weather or a surge in the global economy boosts demand, or if a source fails. The only excess production capacity in the world is in Iraq. The countries in what used to be called the free world will consume 53.5 million barrels of oil per day (b.p.d.) this winter, Mr. Tahmassebi says. To meet the demand, the 13 members of the Organization of Petroleum Exporting Countries (OPEC) will have to produce 24 million b.p.d. - about what they are pumping now. Oil traders in the United States, wary of a disruption, have run the price of domestically produced oil up to $24 per barrel lately. "I can see why some people are nervous," Tahmassebi says. He and other analysts are watching three countries: Kuwait. Last spring the retreating Iraqi Army set fire to 745 oil wells in the Persian Gulf sheikdom. Well-control specialists first predicted that it would take two years or more to snuff them all. But only nine months will be required because the government of Kuwait "spared no expense," says John Burton of Wild Well Control in Houston. The Kuwaitis deployed 28 teams of firefighters from North America, Europe, and even Iran and China. Fewer than 100 wells are still burning, and those will be put out by Nov. 20, Mr. Burton says. But much cleanup and repair work must be done to restore Kuwait's former production capacity of 3 million b.p.d. Kuwait is producing up to 400,000 b.p.d. now, Tahmassebi says. That figure could double by the end of 1992, but little increase will be seen over the winter. The Soviet Union. Oil analysts have been concerned that economic and political disintegration would disrupt Soviet petroleum exports this winter. The economic treaty signed by eight of the remaining 12 Soviet republics might help stabilize the situation there, says Robert Ebel, an expert on Soviet oil with Enserch Corporation. But he warns that the treaty is vague. "We've been through these kinds of economic agreements before and they've fallen apart" when the details were tackled. Reporters in Moscow have picked up rumors that another coup attempt will come after the winter, once food stocks have run low. Ed Krapels, president of Energy Security Analysis, sees logic in the timing. "The winter may create the misery that gets people out on the streets in the spring," he says. "But it's awfully hard to riot when it's 30 below." Even if politics don't interrupt Soviet exports in the next few months, other factors might a year from now. "It's not very difficult to construct a scenario for the beginning of the winter of 1992 where the Soviets for all practical purposes are out of the world oil market," Mr. Ebel says. "Gradual but continual deterioration" of the Soviet oil industry has been under way ever since Moscow stopped spending so much of its nondefense budget on the oil sector so that President Mikhail Gorbachev could deliver more housing and consumer goods to his people, analysts say. "The investment that they didn't make a couple years ago is now catching up with them," Ebel says. Badly needed foreign investment in the country's oil industry is coming slowly. Further, unrest among coal miners and the plateauing of Soviet natural gas production have boosted domestic demand for oil. Ebel expects net Soviet exports to fall from last year's 2.9 million b.p.d. to an average of 1.7 million b.p.d. this year. Next year's level could be 200,000 b.p.d., he warns. Iraq. Despite war damage, Iraq is believed able to produce up to 1 million b.p.d. No other country has so much unused capacity. The United Nations has given Iraq permission to sell $1.6 billion worth of oil - about 500,000 b.p.d. over a year's time. But the UN imposed conditions that Iraq doesn't like. So despite its own dire needs, it hasn't exported any oil. "How long can they hold out?" Ebel wonders. Adds Krapels: "If they don't come into the market, it will be tight." Tahmassebi says the situation is manageable. "Let's say that tomorrow we wake up and find out that there is a civil war going on in the Soviet Union, and their export of oil is almost completely stopped." All the UN has to do is "relax a little bit and let Iraq produce and export so that we can meet the shortage."