Despite the Iranian oil shutdown, oil production worldwide was higher during the first two months of this year than in January and February of last year, according to the Central Intelligence Agency.

In addition to Energy Department documents drawing on CIA statistics, oil production from the Organization of Petroleum Exporting Countries (OPEC) rose from 27.9 million barrels a day in 1978 to 28.6 million barrels a day this year, even though Iran, formerly the cartel's second-largest producer, was exporting no oil.

Energy Secretary James R. Schlesinger has said repeatedly that the drop in production resulting from the Iranian revolution caused a world oil shortage of 2 million barrels a day-with a half-million barrels a day or more of that shortfall affecting the United States.

According to a DOE memo, however, government analysts conclude that during the first two months of this year, worldwide production (including OPEC) was 60.1 million barrels a day compared with 57.3 million barrels a day last year.

Similarly, oil production from countries outside the oil cartel rose from 29.4 million during the first two months of 1978 to 31.5 million barrels a day this year.

While in the past some CIA oil analyses have been questioned, the Energy Department relies on the agency's statistics for its calculations of worldwide oil production.

In a memo to Deputy Energy Secretary John F. O'Leary citing CIA statistics, Lincoln Moses, head of the DOE's Energy Information administration said, "I was wrong about world oil production, which these figures show to be above January and February of 1978."

In the memo, a copy of which was obtained by The Washington Post, Moses adds that production went down in January and February when compared with the last two months of 1978. There was a similar drop during January and February last year, compared with the year before.

Moses also wrote that non-OPEC production "has been appreciably higher" this year compared to 1978's first two months. "The increase in non-OPEC oil between the two periods is 2 (million barrels a day), that is large but not unbelievable," Moses wrote.

He also pointed out that non-OPEC production rose 2.7 million barrels a day in the 13-month period following November 1977 to its current level. This increase was the result of stepped-up production from the North Sea, Mexico, Canada, and some Third World states.

Since January 1977 Arab OPEC production rose from 16.4 million barrels a day to 21.2 million barrels a day in January this year, while the output of the cartel's non-Arab producers declined from 10.8 million barrels a day to 7.2 million barrels a day in January. Non-Arab production has since begun to rise. The total increase in OPEC second-leading producer - Kuwait, production resulted from higher out-put from Iraq-now the cartel's Saudi Arabia, Venezuela, and Nigeria.

On Friday Schlesinger defended his department's shortage estimates on Capitol Hill. Also, he told the National Association of Manufacturers in a breakfast speech that continuation of the projected shortage would depend largely on "whether production will be cut back" by other OPEC countries as Iran increases its output.

Iran is now producing nearly 3 million barrels a day, compared to more than 5.5 million when the shah was in power.

Some international oil analysts, however, question DOE's interpretation of oil production and inventory data.

One, Bruce Wilson of Smith, Barney, Harris, Upham, says, "If you look at the numbers there probably was no shortage in excess of 1 million barrels a day worldwide."

He adds that "Schlesinger has tried to rationalize a larger shortage," saying that because of higher prices and profits available in Japan and Europe major oil companies have shifted some of their supplies there instead of to the United States.

Energy Department officials now concede that world production has gone up this year compared to last year even though Iran was shut down for more than 2 months. But they stick by their assessment that there is still a 2 million barrel a day shortage because of higher demand.

The Central Intelligence Agency's energy forecasts have sparked controversy in the past. The CIA's 1977 forecast of a world oil shortage triggered by anticipated declines in Soviet oil production, as well as the agency's published data in 1978 on Saudi Arabia's productive capacity, were both challenged by oil experts.

Schlesinger and John Treat, one of DOE's leading international oil specialists, say that the shortage will continue unless production remains high enough to allow oil companies to rebuild inventories during the spring and summer.

Still another factor is oil consumption.

Albert H. Linden Jr., assistant administrator of DOE's Energy Information Administration, says that demand for oil this year is running about 3 percent in excess of last year's consumption level.