M. H. Kazemzadeh; A. Sadeghi; M. H. Adabi; H. Ghalavand
Abstract
In order to determine biostratigraphy, depositional environment and sequence stratigraphy of the Kalat Formation in the Sheikh Syncline (north east of Bojnurd), Four stratigraphic sections including South Sheikh, North Sheikh, Qaleh Zu and Ziarat were selected and sampled. The thickness of the Kalat ...
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In order to determine biostratigraphy, depositional environment and sequence stratigraphy of the Kalat Formation in the Sheikh Syncline (north east of Bojnurd), Four stratigraphic sections including South Sheikh, North Sheikh, Qaleh Zu and Ziarat were selected and sampled. The thickness of the Kalat Formation in the South Sheikh, North Sheikh, Qaleh Zu and Ziarat sections were 25, 16, 25 and 5m respectively, and its lithology consists mainly of brown to yellow limestones. The reason of changes in thickness in studied sections is tectonic factors, subsidence and different rates of sedimentation. The layer of conglomerate in the base part of the Kalat Formation at South Sheikh and Qaleh Zu sections and the layer of sandstone in the base part of the Kalat Formation at Ziarat section were recognized. In the biostratigraphic studies, 15 species belonging 23 genera of foraminifera were recognized and one biozone including Siderolites calcitrapoides-Sirtina orbitoidiformis assemblagezone was identified. The age of the Kalat Formation in all of studied sections based on the above biozone and fossil contents Maastrichtian were determined. Petrographic analysis led to recognition two silliciclastic and eight carbonate facies belonging to four depositional environments including tidal flat, restricted and semi-restricted lagoon, shoal and open marine. Based on the recognized facies and its gradual trend, abundance of shoal facies, absence of reefs and sediment of turbidite flows such as Falling and sliding sediments, the sedimentation of the Kalat Formation was occurred on the homoclinal ramp setting. Based on the vertical changes of facies and recognized depositional environments, one third-order depositional sequences was represented. This depositional sequence consists mainly of shoal facies rich in bioclast, intraclast, benthic foraminifera, echinoid, rudist (Hyporite) and bivalve. MFS of this sequence is represented by open marine facies rich in echinoid.
E. Asadi Mehmandosti; Sh. Alivand; H. Ghalavand; A. R. Rostami
Abstract
Nuclear magnetic resonance (NMR) is a test method that has had basic influence on the accuracy of reservoir parameters prediction. In this study, petrophysical properties of the Ilam Formation in one oil field of the Abadan plain were investigated by Nuclear magnetic resonance method, and core analysis ...
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Nuclear magnetic resonance (NMR) is a test method that has had basic influence on the accuracy of reservoir parameters prediction. In this study, petrophysical properties of the Ilam Formation in one oil field of the Abadan plain were investigated by Nuclear magnetic resonance method, and core analysis and thin sections data were used to validate the test results for the first time. The Nuclear magnetic resonance method was used to determine reservoir parameters such as porosity, permeability and rebuilding of capillary pressure curve in studied oil field. Correlation between petrophysical results of Nuclear magnetic resonance method, core data and microscopic thin sections indicates effectiveness of this method in determining the reservoir parameters. In addition, evaluation of the Ilam Formation carbonate with NMR method indicates that the studied reservoir at depths of 2890 to 2846 m has suitable reservoir quality in terms of hydrocarbon storages in studied oil field in Abadan plain.
M yavari; M Yazdi; M.H Adabi; H Ghalavand
Abstract
Dariyan Formation deposited in two different sedimentary settings. In some places it consists of shallow Limestone with algae and Orbitolina and in the other places in addition to limestone, it represents black shales and marls associated with planktonic foraminifera and radiolarian. In this research ...
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Dariyan Formation deposited in two different sedimentary settings. In some places it consists of shallow Limestone with algae and Orbitolina and in the other places in addition to limestone, it represents black shales and marls associated with planktonic foraminifera and radiolarian. In this research Draiyan Formation was studied in order to microfacies, depositional model and sequences stratigraphy of two sections so called, Kuh-e Gadvan and Kuh-e Banesh in high Zagros belt. Detailed petrographic studies led to the recognition of five main facies belts including: lagoon, bar, shallow open marine, outer ramp and deep marine. According to the vertical and lateral variations of facies, the Dariyan Formation deposited on a carbonate ramp platform and intrashelf basin. Depositional sequences have been presented on the basis of analysis of facies, fauna assemblages, Gama and Neutron logs. Three 3rd orders depositional sequences have been recognized during deposition of sediments. There is Type I sequence boundary in the top of third sequence and the other two sequences was considered as Type II sequence. Sea level fluctuations of the studied area correlated with Arabian platform and these changes follow of regional factors.
