Oil Reserves in Iran - Additions To Reserves

Additions To Reserves

Iran oil reserves at the beginning of 2001 were reported to be about 99 billion barrels; however in 2002 the result of NIOC’s study showed huge reserves upgrade adding about 31,7 billion barrels of recoverable reserves to the Iranian oil reserves.

The 2002 NIOC reserve revision came from the following sources:

• Revision of oil-in-place volume which added 14,3 billion barrels of oil to Iran’s Oil in place reserves.
• Revision of the field’s recovery factors which increased average recovery factor of the revised oil fields from 29% to 36%.
• South Pars gas field liquefied petroleum gas reserves (C₃ and C₄) about 3,2 billion recoverable barrels.
• New discoveries about 700 million recoverable barrels.

In addition to the large reserves, Iran still has huge potential for new significant gas discoveries: areas like Caspian Sea, North East, Central Kavir and especially areas starting from Aghar and Dalan gas fields in Fars province up to the Strait of Hormuz and Central Persian Gulf have considerable amount of undiscovered gas resources. According to Exploration Directorate of NIOC, there are about 150 unexplored anticlines in Iran.

Since 1995, the National Iranian Oil Company (NIOC) has made significant oil and gas discoveries, standing for some 84-billion-barrel (1.34×1010 m3) of oil in place and at least 191×10^12 cu ft (5,400 km3) of gas in place, which are listed below.

In the Zagros and Persian Gulf Basins the highly porous Cretaceous and Tertiary carbonate rocks make very important oil reservoirs, while Permo-Triassic carbonates, particularly the Dalan and Kangan formations, are the main gas and condensate reservoirs. It is reported that 38 gas/condensate pools have been discovered in the Dalan and Kangan formations in these basins alone. The mid-Cretaceous Sarvak formation is significant for the volume of recoverable oil it holds, while the Oligo-Miocene Asmari formation is the best current producer.