The 13 OPEC oil ministers ended a meeting here today with hints that a small rise in the price of oil in 1978 was likely.

The routine session for the ministers of the Organzation of Petroleum Exporting Countries was not called to fix the 1978 oil price.

But OPEC ministers did fix a date and place - Dec. 20 in Caracas, Venezuela - for an OPEC session to do just that. And some ministers also gave reporters broad hints on how they were thinking.

Saudi oil minister Ahmed Zaki Yamani, said in a Swedish television interview Tuesday night that he favored freezing prices at the current benchmark of $12.70 a barrel through 1978.

Today, Yamani said President Carter is doing everything in his power to advance peace in the Middle East, and the Saudi minister called for an 18 month freeze on OPEC oil prices as a reward. Asked if Carter should be doing anything more in the Middle East, Yamani replied: "Nothing to my knowledge."

Algeria's new oil minister, Sid Ahmed Ghozali, seemed to reflect the majority feeling when he said today it was too early to speak in detail about 1978 prices, but he said he thought the ministers would discuss a small adjustment in prices when they meet again in Caracas.

The oil minister of the United Arab Emirates, Mana Said al-Oteiba, told reporters he thought prices were likely to be increased at the next meeting.

Taken together, these statements led oil analysts to predict a moderate price increase in the new year.

Libya also said a minimum increase of 10 per cent would be justified. Libya, Algeria and Iraq also warned of the possibility of a new spilit within the organization and another round of two-tiered prices if the Saudis and Iranians insist on a price freeze at the next OPEC meeting in Caracas.