In his recent meeting with President Carter, the shah of Iran talked of giving "a break" to the troubled industrial world by attempting to keep oil prices down. After a trip to the Middle East, Treasury Secretary W. Michael Blumenthal also expressed hope that the oil-consuming world, which has not yet fully absorbed the massive price boosts of 1973-4, wouldn't have to face yet another.

But in a conversation on his way through London the otherday, oil consultant Walter J. Levy took a much more pessimistic view. The shah may be reasonable for the time being, Levy figures, thus reinforcing the conversative views of Saudi Arabia.

Inevitably, though, Levy predicts that the colossal U.S. appetite for oil will go up rather than down, "and undoubtedly we will be facing a shortage in physical terms some time in the 1980s. "Levy's views on oil are given more attention by Western governments than those of any private analyst. His record isn't perfect (whose is? but he's been right uncomfortably often.

The implications of Levy's forecast are both frightening and staggering. It means, first of all, that efforts to conserve energy and reduce imports - especially by the United States - wil be a failure. The lack of congressional willingness to come to grips with the energy problem would seem to bear out Levy's judgement. And if, indeed, oil consumption goes up instead of down, he says, "There is likely to be a new price explosion in oil before the physical limit is met."

THIS SCENARIO runs counter to some that predict a surplus, even a glut, of oil as new sources develop. But there have been no major proven finds of oil since the North Sea and the Alaska Slope, and little progress in developing alternatives to petroleum.

The more optimistic scenarios also assume that the Saudis - by far the biggest supplier - have developed a special "connection" with the United States that would inhibit any decision to keep the oil in the ground in order to prolong the life of an exhaustible asset.

But who can be sure how Saudi policy will develop if U.S. imports continue at the present greedy $45 billion pace. That not only would hasten the day when the Saudi oil sands run dry, but cause a dollar depreciation reducting Saudi wealth held in dollar assets.

The real thrust of Levy's analysis is that the world only has tricked itself into thinking that it has met the crisis posed by the oil cartel's price demands, by "recycling" the Arab surplus money into loans for oil-importing countries.

Assuming an inflation adjustment plus additional real increases in the price, Levy predicts a world oil bill of more than $400 billion a year (in then current dollars), of which the United States would be paying $100 billion.

ECONOMIST Robert Solomon has argued that members of the Organization of Petroleum Exporting Countries are "necessitous lenders," which means that they have to alternative except to lend the surpluses back to the rest of the world, mostly through buying securities such as U.S. Treasury obligations.

But Solomon's assessment assumes that the debt will be repaid - ultimately - when the OPEC nations themselves move into deficit by importing more goods than they export. But this process hasn't happened. OPEC surpluses have been reduced only modestly from their peak and, if Levy is right, they're headed up in a sort of Phase Two of the oil crisis.

As Solomon admits, until and unless the OPEC surpluses are wiped out, there is no way for the debtor countries to repay their debt. All this spells continued trouble for the oil-consuming countries, especially the developing countries. According to Shinsaku Hogen of the Japanese International Cooperation Agency the poor nations of the world already are paying more in interest and principal to the rich each year than they are receiving in new aid.

If oil prices zoom in the scale predicted by Levy, the Third World debt will increase, the rich nations will plead they can spare no additional aid, but demands for debt forgiveness will rise to a crescendo.

There was a time, not too long ago, that the less-developed countries bought OPEC's lin ethat higher oil prices struck a blow for all the under-privileged of the world, who then could raise the prices of their own commodity exports to compensate for higher costs of oil.

Instead, the oil-induced world recession caused a collapse in world commodity prices. Now the poor nations would like their Arab brothers to give them a lower price for oil than they charge others or lend them the difference. But the OPEC nations appear to have no intention of making it easy for anyone.