Reservoir properties controlling on ooidal and mudstone facies in Kangan Formation, South Pars Gas Field

The Kangan (Early Triasic) and Upper Dalan (Late Permian) formations form the important gas reservoirs in Iran. The ooidal grainstone and mudstone facies form more than of 75 percent of Kangan Formation. Therefore, recognition of controlling processes of reservoir properties on these facies lead to understand the reservoir quality on whole formation. In this study, based on recognition of microfacies and depositional environments, petrophysical properties of Kangan Formation are investigated. Results show that the grain-dominated facies have better reservoir quality, and dissolution of allochems on these facies (grain dominated), dolomitization and fracturing caused to increasing reservoir properties. However, calcite cementation, anhydritization and compaction decreased the reservoir quality.