Sedimentary Environment of Asmari Formation in Parsi Oil Field with special reference to anhydrite development between Asmari and Pabdeh formations

Category Sedimentology
Group GSI.IR
Location The 24 Symposium of Geosciences
Author A-Hasanvand
Holding Date 19 August 2007

Abstract:

The Oligo-Miocene Asmari Formation is one of the most important reservoir units of the Parsi Oil Field that is located in North Dezful Embayment in SW of Iran.
 This formation
is laid over the shales of Pabdeh Formation concordantly and is overlaid concordantly by evaporates of Gachsaran Formation. Asmari Formation is composed of carbonate rocks (limestone & dolomite) associated with thin shale interlayers anhydrite. Considering gradual shallowing upward and associated facies, basal anhydrite is considered to be formed in early diagenetic condition during sea level fall in dry and hot climate in shallowing upward sequence in the supratidal environment.

In order to study of sedimentary environment of Asmari Formation in parsi oil filed, cores, cuttings and logs from wells A and B were investigated. Petrographic studies resulted in determination of 18 microfacies which grouped as open marine, barrier,shallow subtidal facies, reef, lagoon, supratidal and intertidal facies.

The Correlation of mentioned micofacies with standard model of carbonate from ramp environment (Buxton & Pedley, 1989), show that Asmari Formation was deposited in a carbonate ramp which some local reef or patch reef.

tags: QAZVIN