Sedimentological studies of marine oil fields in order to reduce drilling risk and environmental pollution: a case study of South of Iran

Abstract

Detailed studies of sedimentology and petrology of oil fields, especially oil fields located in the seas, play a very important role in reducing the risk of danger, increasing harvest, and reducing the amount of environmental pollution. The South Pars gas field in the waters of the Persian Gulf on the joint border line of Iran and Qatar and on the south coast of Iran has been used as a comprehensive model for this type of study. In these studies, the sedimentary environment and sequential stratigraphy of the Scorpion and Sarvak Formations in the South Pars gas field in wells 1 and 3 have been investigated. Microscopic studies and analysis of gamma-ray and acoustic diagrams of these formations have led to the identification of 9 facies in three facies belts related to wetland, dam, and open sea. Dam facies have been identified only in Sarvak formation. This study shows that the facies belts of the abovementioned formations in a ramp platform are also sloping. Sequence stratigraphy of Kazhdomi and Sarvak Formations in the study wells shows that Kazhdomi Formation has one sedimentary sequence (third category cycle) and Sarvak Formation has two sedimentary sequences. The lower boundaries of sequences 1 and 2 and the upper boundary of sequence 3 have type 1 (SB1) discontinuities, and the boundary between sequences 2 and 3 has type 2 (SB2) discontinuities.