-Deformation analysis in the Pazanan Anticline based on subsurface data and geometric characteristics

Document Type : Original Article

Authors

1 Department of Sedimentary Basins and Petroleum, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran

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

3 ., Exploration Directorate, National Iranian Oil Company, Tehran, Iran.

10.22077/jt.2024.7113.1170

Abstract

The Pazanan anticline is one of the most important condensate gas reservoirs in Iran, which is located in the southeastern part of the Dezful Embayment with a northwest-southeast trend.The structural analysis and deformation of this anticline based on the interpretation of existing subsurface data(including 3D-seismic data and drilled wells data) indicates that the folding style of this anticline in the Asmari reservoir and older formations is faulted asymmetric detachment folding.Based on the structural interpretation of the tops of the Asmari, Sarvak, Fahliyan, Gotnia formations and a deeper horizon(probably top of the Kangan) in the transversal seismic sections of the Pazanan anticline, it could be divided into 3 main culminations known as southeastern, central and northwestern, which are separated from each other by saddles.The interpretation of the observed seismic data and stratigraphic column clearly shows that the sedimentation thickness of formations, especially the Late Cretaceous and Paleocene,have been reduced due to the uplift of the Hendijan-Izeh Paleo-high, so that the Ilam and Gurpi formations have not been deposited or eroded in the Paleo-high area.The interpretation of the Asmari reflector in the seismic time slices, with assuming that the changes in the spatial dimension (along the axis of the Pazanan anticline) are equivalent to the changes in the time dimension(during the folding time of the anticline);shows folds growth in the central and southeastern culminations of the Pazanan anticline were simultaneously but separately,while the northwestern culmination of this anticline started to folding after increasing the deformation and finally connected to the central culmination.

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