Asghar Ahanjan - Post graduate student, Petroleum Engineering Department, Petroleum University of Technology(PUT) , Tehran, Iran and IFP school, Paris, France
Arsalan Zeinalzadeh - Exploration& Production Department, Research Institute of Petroleum Industry(RIPI), Tehran, Iran
Mahmoud Memariani - Exploration& Production Department, Research Institute of Petroleum Industry(RIPI), Tehran, Iran
Shahram Sherkati - Geology department, Exploration Directorate, NIOC, Tehran, Iran

Marun oil Field is one of the giant oil field in Dezful Embayment SW Iran which produces from Asmari limestone of Oligo-Miocene and Bangestan of middle Cretaceous.The main source rock is Kazhdumi of Albian with average thickness of 230 m, Type II kerogen, Marl-carbonate lithology which was deposited in a depression corresponding to the Present-day Dezful embayment and extending towards the northeast.Modeling with Temis 2-D showed that in this field, Kazhdumi is mid-mature at present in anticlinal parts, in peak oil generation window in flank of anticlines. If Kazhdumi buried to synclinal depth will be in gas generation window. The onset of oil generation was reached by middle Miocene during deposition of Gachsaran Formation and expulsion occurred by late Miocene at about 10 Ma with beginning of Zagros folding and during deposition of Mishan formation.Migrations took place almost vertically in crest and flank of anticlines and were facilitated by intense fracturing whereas in synclines migration occurred horizontally along career beds