عنوان مقاله [English]
This paper is intended to investigate the diagenetic processes and its effects on the reservoir quality of Fahlian carbonate formation in the early Cretaceous in the subsurface section of the well 1 and 2 of Arvand oil field located in Abadan plain, out based on full use of cores and 229 thin sections, well logging data, petrophysical testing data of two wells. Diagenetic events showed that cementation, dissolution, compaction, replacement, dolomitization, micratization, dissolution are the most common diagenetic processes affecting the Fahliyan Formation in Arvand Field. Among the processes mentioned above, cementation and physical compaction have caused porosity to disappear, and dissolution and dolomitization have increased it. Due to its dolomitization and dissolution along with it, the acetylation of the cell increases the quality of the reservoir, and in some cases, due to the concentration of the decomposition remains, it has caused permeability. In the thin sections studied, the observed porosity is of a type of membrane, intergranular cavity and fracture. Based on petrophysical studies of the studied reservoir, the Fahlian Formation is mainly composed of lime and variable amounts of shale and clay minerals of illite and montmorillonite type. Water saturation is 10 to 40 percent, and water and oil are fluid, with a high water saturation percentage. Due to the lack of expansion of the diagenetic processes affecting reservoir quality and the high volume of calcareous muds affected by sedimentary environment, the quality of reservoir of Fahliyan Formation in Arvand field has been low.