Microfacies, sedimentary environment and diagenesis of the Asmari Formation in Chahar Bisheh Oil Field, south west of Iran

In this research, two subsurface sections consist of well No.2 and No.3 from the Asmari Formation with a thickness of 423 and 412 m respectively in Chahar Bisheh oil Field have been studied. The Asmari Formation in this field consists of intermittent layers of limestone and dolomite, very thin shale layers and anhydrite interlayers. Based on petrographic studies and identification of microfacies, 15 microfacies and 1 lithofacies in 4 facies belts consist of tidal flats, lagoon, shoal and open marine for the Asmari Formation have been recognized and sedimentary environment of this formation, is a Homocline ramp carbonate platform. Effective diagenetic processes including cementation, dolomitization, compaction, fracturing, dissolution, micritization, pyritization, geopetal fabric, boring, silicification and neomorphism which has influenced the Asmari Formation by all three marine, meteoric and burial diagenetic environments.