Diagenetic history of Asmari Formation and itsInfluence on reservoir quality of Kupal oil field
Oligo-Miocene Asmari Formation is the most important reservoir rock unit in the oil fields of southwest Iran. The formation is comprised of limestone, dolomite, shale and sandstone which are mineralogical susceptible to diagenetic processes. Considering the significant role of diagenetic features/processes on reservoir quality, the diagenetic history of the formation is investigated in Kupal field. The cores and thin sections from available cores and cutting are used for such a purpose.
The major diagenetic processes in the formation are micritization by Micro-organisms, cementation, dissolution, neomorphysm, dolomitization and anhydritization. Results from this study lead for recognition of marine, meteoric and burial diagenetic environments. Diagenetic features related to fresh water phreatic environment along with those of marine phreatic environment show that the studied sediments were affected by meteoric processes before burial diagenesis. This paper briefly discusses the role of each process and resulted products in reservoir quality.