The United States seems likely to import much more oil this year than the Carter administration earlier estimated, and will come very close to the president's much-advertised ceiling of 8.2 million barrels a day.

If the recession is weaker and the winter weather harsher than expected, imports easily could exceed the ceiling, and the president would be called upon to turn some oil away, according to new estimates.

The administration had thought the limit was set high enough to avoid such action so soon. "I'm surprised and a little startled," an administration economist said yesterday. "It looked like we had a fair amount of room when we set those quotas."

When President Carter set the ceiling in his energy address last month, the administration estimated that crude oil imports were running at an annual rate of 7.8 million barrels a day, a comfortable 400,000 barrels a day below the ceiling.

At the time, several European energy officials were critical of the 8.2-million-barrel-a-day ceiling, claiming that the United States would not have to make any sacrifices to stay under it, while their countries were making concessions.

But now the Energy Department has revised its estimates to show crude oil imports running at an annual rate of between 8.1 million and 8.2 million barrels a day. While still below the ceiling, the import levels are high enough that a change in economic factors could force Carter into the difficult position of restricting oil imports.

Such action, forcing consumption cutbacks and possibly leading to further price increases, in the midst of a recession and in the winter before a presidential election, would be politically painful.

DOE and White House officials were unable to pinpoint specific reasons for the changes in the estimates.

A White House economist acknowledged that the Energy Department had been dealing regularly with higher import estimates than its White House counterparts. But, he added, it was assumed at the White House that the DOE estimates would be revised downward as better import information became available.

"We never really used the 7.8-million-barrel figure over here," said a DOE official. "Actually, our projections all along have indicated that we would be somewhat snug up against the quota."

Support for the higher DOE estimates came yesterday in the revised forecasts for imports during the third and fourth quarters of 1979.

The administration and DOE had expected the earlier estimates of imports during those periods to drop somewhat as better information became available. The new information, they theorized, would reflect the drop in imports resulting from the 25 percent price increase levied on crude oil by the Organization of Petroleum Exporting Countries (OPEC) in June.

In fact, the new projections released yesterday for those two quarters are lower than the earlier ones, but not as low as officials had expected. Consequently, DOE statisticians are now firmer in their belief that the administration has little room to play with in keeping under the ceiling.

And it is now apparent that the administration's hopes of keeping under the ceiling without having to curtail consumption rest precariously on certain economic factors, the DOE economists said.

If, for example, the recession predicted by the administration is mild, demand for petroleum products will not drop much, and crude oil imports could run higher.

In addition, if it is a harsh winter, demand for such products as heating oil will rise above estimates, and imports also would increase.

The combination of both factors would almost surely force Carter to impose import restrictions to stay below the 8.2-million-barrel-a-day ceiling.

On the other hand, DOE and White House officials are quick to point out, there are many conditions that could lead to reductions in oil imports. Factors such as further unrest in Iran, a bad recession, a mild winter and further increases in the price of imported oil could each guarantee that the ceiling would not be reached.