Some of this town's old school ties have an international stripe

One of the themes that runs quietly through Tulsa's economy, like a yarn in the weave of a subtle tweed, is the city's international connections, particularly in the fields of energy technology and aeronautics.

Even as Oklahoma's reserves of oil have been drawn down over the long years of production, oil technology expertise has grown.

Tulsa has become a world leader as a center of the heat-exchanger technology necessary in oil refining. Another Tulsa specialty is the pollution-control technology used in oil refining.

The John Zink Company, a unit of the Chicago-based Sunbeam Corporation, draws industry professionals from around the world - from wherever there's oil and petrochemicals - for its intensive seminars on efficient operation of furnaces in refineries and chemical plants.

A more traditional, academic , and better-known setting is the University of Tulsa, a private, nonsectarian institution, whose school of petroleum engineering is considered one of the best in the world.

One of the prize alumni of this small and selective school (500 undergraduates, 50 graduates) is Venezuelan oil minister Dr. Humberto Calderon Berti. Other notable alumni include high officials of state oil enterprises in Indonesia, Malaysia, and Abu Dhabi, according to a longtime professor, Dr. Kermit Brown.

Near the airport north of town, on one of Tulsa's relentlessly straight mid-American roads, is the unprepossessing corrugated-metal building housing the offices of the Spartan School of Aeronautics.

This operation, too, has an oil connection. It was founded in 1928 by oilman William G. Skelly and later owned by J. Paul Getty. Mr. Skelly was a leader of a group of oil people who, feeling that Tulsa should be an aviation capital, bought a wheat field and gave it to the city for use as an airport.

During World War II this school had a distinguished record of training pilots for the military. The government, unprepared for war, turned to private schools to provide primary flight training in a hurry. Spartan turned out 14,000 cadets - more than any other such school.

The Spartan school, now owned by the National Education Corporation, draws students from all over the world. Currently it has some 100 students learning to be pilots and 1,900 learning to be mechanics. Some 15 percent are foreigners, largely from third-world countries that have bought planes from the United States for their air forces or national airlines and want to have their pilots and mechanics trained here as well.