Stratigraphy and Palaeontology
Mahmoud sharafi; Nasim Mousavi; Mehran Moradpour; Bijan Biranvand; ebrahin Abdollahi; Hossein Soltani
Abstract
Based on lithostratigraphy analysis, Cheleken Formation in the studied section of the Gorgan plain, subdivided into lower sandstone and upper mudstone/marl units. Based on petrographic analysis, the sandstone sediments include low textural and compositional maturity litharenite and sublitharenite. Conglomerates ...
Read More
Based on lithostratigraphy analysis, Cheleken Formation in the studied section of the Gorgan plain, subdivided into lower sandstone and upper mudstone/marl units. Based on petrographic analysis, the sandstone sediments include low textural and compositional maturity litharenite and sublitharenite. Conglomerates are polymictite orthoconglomerate with variables carbonate and chert grains. High percentage of the porosity as vuggy, channels and fractures in the sandstone and conglomerates and even mudstone deposits displays high reservoir potentional for the studied sediments and hence necessitates the exploration studies in the Iranian part of the SCB. Based on the youngest nannofossil species, a late Miocene to middle Pliocene (?) age is defined for the Cheleken Fm. in the studied area. Nannofossils distribution of the studied succession displays the SCB was connected to the Black Sea and Mediterranean Basin in the late Miocene- early Pliocene and the Pleistocene and was isolated in the main part of the Pliocene.
S. Nezamvafa; M. Rezaee; R. Moussavi-Harami; M. Bargrizan; A. Chehrazi
Abstract
Investigation and detail recognition of hydrocarbon reservoirs can have a good help in management of production wells, and field development. Burgan formation is deltaic sandstone from lower-median Cretaceous that is divided into three zones, A, B, and C. This formation ...
Read More
Investigation and detail recognition of hydrocarbon reservoirs can have a good help in management of production wells, and field development. Burgan formation is deltaic sandstone from lower-median Cretaceous that is divided into three zones, A, B, and C. This formation in its type section (Kuwait) makes the second biggest world reservoir, with up to 72 billion barrels of in situ oil. In this study, evaluation of reservoir parameters has been made for this formation. Volume of shale, porosity, permeability, saturation, determination of oil water contact (OWC), net/gross and hydrocarbon column thickness, are the main reservoir parameters, that have been calculated with deterministic and problistic method using different logs and core data of 36 wells.
All of these parameters in problistic method have been calculated by professional petrophysic software, Geolog. Results of calculations show that despite of B zone lower thickness; this zone has a very high reservoir quality than the other two zones. This high quality arises from clean sand and high porosity (intergranualr) and permeability of this zone. Higher thickness of Burgan formation and its reservoir zones in the west of study field, and reservoir high quality in these horizons, show that the original source of clastic sediments is form the Arabian Shield toward Iran.
