Burial History Reconstruction and Hydrocarbon Generation modeling of Probable Source rocks in two Gas Fields, South of Iran

Authors

1 M. Sc., in petroleum geology, Dept., of Sedimentary Basins and Petroleum, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran

2 Assist. Prof., Dept., of Sedimentary Basins and Petroleum, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran

3 Assoc. Prof., Dept., of Sedimentary Basins and Petroleum, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran

4 Dept., of hydrocarbon systems studies, Exploration Directorate of NIOC, Tehran, Iran

Abstract

The Fars region in Iran is one of the richest places in the world in terms of gas reserves. The area investigated in this study is located on the coastal Fars subzone. In this research, probable source rocks were evaluated by organic geochemical methods and then 1D petroleum system modeling in two wells from the gas fields of southern Iran was contracted and studied. Based on the vitrinite reflectance data and the current temperatures of the formations in the existing wells, the calibrated model and burial history diagram, kerogen to hydrocarbon transformation ratio (TR), the time and amount of light hydrocarbons (c1-c5) and Liquid hydrocarbons (C6+) expulsed from source rock were determined. The geochemical studies in the area reveals that, the Sarchahan Formation is the main candidate source rock. The results obtained from the modeling show that the Sarchahan Formation in the well of the first and second field generated hydrocarbons from 130 and 140 million years ago respectively. Currently, the thermal maturity of the Sarchahan Formation in the both wells is in the gas window. Up to now, the amount of liquid (C6+) hydrocarbons expulsed from the Sarchahan Formation in the first and the second field is about 23500 kg/m2 and 21300 kg/m2 and for gaseous (C1-C5) hydrocarbons is 23000 kg/m2 and 21200 kg/m2, respectively.

Keywords