University of Isfahan Journal of Stratigraphy and Sedimentology Researches 2008-7888 27 2 2011 08 23 Depositional Environment and sequence stratigraphy of Dariyan Formation in the South Pars Gas field Depositional Environment and sequence stratigraphy of Dariyan Formation in the South Pars Gas field 63 86 16743 FA M Amiri M.Sc. Student, University of Tehran H Rahimpour-Bonab, Professor, Departement of Geology, University of Tehran A Asadi Ph.D Student, University of Tehran M Sarfi M.Sc. Student, University of Tehran Journal Article 2016 06 14 Dariyan Formation is one of the most important hydrocarbon reservoirs of the South Pars gas field. Since abundance of Orbitolina family in these strata, our microfacies analyses are mainly based on their paleoecological characteristics<strong>.</strong> As shown by microfacies analysis in the SPOa and SPOb wells, depsoitinal and textural nature of the Dariyan Formation in this field are entirely different from its type section and the other parts of the Zagros Basin. Detialed sedimentological studies of this unit, its comparison with the Shuaiba Formation (equivalent of the Dariyan Formation in Arabian countries) in the north dome and compilation of these data with the paleogeographic features of Aptian, all are representing a regional carbonate ramp that was bordering an intrashelf leeward flank <strong>)</strong>leeward ramp<strong>(</strong>. Employing different techniques, sequence stratigraphic study is carried out. In this approach facies association variations along with the gamma ray data and biota response to the sea-level fluctuations, are complied to recognize different system tracts in each well. This approach gives a good perspective for reservoir engineering. Vertical facies changes in the Darian Formation show that, on the whole, these strata represent a thirdorder sequence and a HST that belongs to the lower unit. <strong> </strong> <strong> </strong> Dariyan Formation is one of the most important hydrocarbon reservoirs of the South Pars gas field. Since abundance of Orbitolina family in these strata, our microfacies analyses are mainly based on their paleoecological characteristics<strong>.</strong> As shown by microfacies analysis in the SPOa and SPOb wells, depsoitinal and textural nature of the Dariyan Formation in this field are entirely different from its type section and the other parts of the Zagros Basin. Detialed sedimentological studies of this unit, its comparison with the Shuaiba Formation (equivalent of the Dariyan Formation in Arabian countries) in the north dome and compilation of these data with the paleogeographic features of Aptian, all are representing a regional carbonate ramp that was bordering an intrashelf leeward flank <strong>)</strong>leeward ramp<strong>(</strong>. Employing different techniques, sequence stratigraphic study is carried out. In this approach facies association variations along with the gamma ray data and biota response to the sea-level fluctuations, are complied to recognize different system tracts in each well. This approach gives a good perspective for reservoir engineering. Vertical facies changes in the Darian Formation show that, on the whole, these strata represent a thirdorder sequence and a HST that belongs to the lower unit. <strong> </strong> <strong> </strong> https://jssr.ui.ac.ir/article_16743_5fdbe146308eb8f6029fa3421e70dca1.pdf