There are many ways to kill time at boring meetings. Some people like to play imaginative games of tick-tack-toe on ceiling tiles. Others stare at a green felt conference table and envision tricky cue shots. President Reagan is known to doodle caricatures of cowboys and horses.

When the 13 oil ministers from the Organization of Petroleum Exporting Countries gather these days to ponder the world's energy scene, several of them usually find solace from the drudgery of discussing the depressed oil market in a number of exotic pastimes.

Mana Said Otaiba, the United Arab Emirates representative who also now doubles as chairman of OPEC, used to bring his prized pet falcon to the gatherings. The bird accompanied him in a first-class airplane seat.

Since becoming chairman of OPEC, Otaiba has decided to leave his falcon home and pursue more sophisticated forms of whimsy while the tedious talk of spot-market price fluctuations and relative viscosity of crude oils flows around him.

Otaiba has cultivated the habit of composing poems about OPEC's plight, allegedly with the help of a well-versed Palestinian aide. After long contemplation of OPEC's weakened state at the latest meeting here, Otaiba was moved to write: "It's a buyer's market--a flexible fluidity-- And the buyers are now quite changed, Sometimes showing coyness, at others cupidity, No longer fearing boycotts, or shortages in supply, They now dictate conditions, and harsh rules apply. The market, alas, is stagnant, To the whims of buyers over-pliant. For sellers, that's a heavy care, A great predicament."

The consensus view about Otaiba's oeuvre in the realm of rhyme was said to be less than enthusiastic. There was even talk about urging him to bring the falcon back. SAUDI ARABIA'S MINISTER, Ahmed Zaki Yamani, who refrains from public displays of poetry, is still considered among OPEC hands to be the most verbally agile with Arabic prose.

Once, when a reporter pressed him about whether the price of oil would rise or fall, Yamani ducked the question with the serene reply: "I do not wish to rob you of the ecstasy of your curiosity." FOR THOSE OIL MINISTERS less inclined to literary adventure, the Finnish hosts tried to be as accommodating as possible, although the rigid antiterror precautions cramped the style of some of the more flamboyant OPEC delegates.

Those who tried to return to the hotel late at night with new female acquaintances were brusquely rebuffed, regardless of rank, at the hotel gate by security guards. In Geneva, where most OPEC sessions are held, "The hotel people are more understanding about such things," as one delegate put it. DURING THE INTERMINABLE hours while the delegates talk business, reporters and oil industry analysts pitch camp in the hotel lobby where gossip and data bits are traded with the contagious flair of an oriental bazaar.

Within the space of a half hour, you can expect to hear all sorts of contradictions. A rumor that Yamani has abruptly walked out of the conference is traced to the fact that the pilot of his private plane vanished inexplicably, only to buy cigarettes.

The long stretches of boredom, waiting for ministers to emerge from closed-door sessions, tend to increase the flow of falsehoods.

Three or four times in the course of OPEC meetings, just when a few reporters' heads begin to jerk with drowsiness, tedious spells are broken by doomsday cries that the cartel is on the brink of collapse. The ministers, it is said, must be shouting and scheming how to cover up the fiasco.

Such dire predictions have not, as yet, been fulfilled, but OPEC's problems in recent months of dividing up a glutted oil market have given rise to more doubts than ever about the cartel's chances for survival.

Even Otaiba has adopted a more somber tone in his most recent verse: "To strengthen a market that's meek, No surer way than to seek, Through agreement by each on a modest share. But if you then again come back To disputes, then too come setbacks, And disaster will loom in the air."