N.I.O.C

National Iranian Oil Company

I.O.E.C

Iranian Offshore Engineering and Construction Company

N.I.S.O.C

National Iranian South Oil Company

S.Z.O.G.P.C

South Zagros Oil & Gas Production  Company

I.O.O.C

Iranian Offshore Oil Company

I.C.O.F.C

Iranian Central Oil Fields Company

W.O.G.P.C

West Oil & Gas Production  Company

P.E.D.E.C

Petroleum Engineering and Development Company

E.O.G.P.C

East Oil & Gas Production  Company