Ali Osouli said deepwater drilling is a branch of knowledge owned by only a few big companies in the world.

"At present, Iran is at the top of Caspian Sea littoral states to that effect," he said.

Osouli said studies by major oil companies in the world show that drilling in Caspian Sea deep waters requires huge investment.

He said the offshore Sardar-e-Jangal oil field in north of Iran promises economic development and industrial growth.

He said more studies are needed to make more finds about hydrocarbon reserves in the Caspian Sea.