The Study of Reservoir Zones of Asmari Formation Based on Sequence Stratigraphy and Well-logging Data in a Southwestern Oil Wells of Iran

Abstract

Asmari formation in Maroon Oilfield is made up of fossil-bearing limestone, dolomitic limestone, argillaceous limestone, sandstone and shale. It is the main reservoir rock for multiple oil wells of Zagros. The formation in Maroon Oilfield dates back to Oligocene(Rupelian – Burdigalian). In the present study, sequence stratigraphy and depositional environment of Asmari Reservoir Formation located in Maroon Oilfield are studied through well-logging data. The lower limit of Asmari Formation in the studied area is Pabede Formation and its upper limit is Gachsaran Formation. The lower limit between Asmari and Pabede formations and upper limit between Asmari and Gachsaran formations are not continuous and signs of discontinuity are observed in them. The field, macroscopic and microscopic studied and determination of percentage and type of allochem and orthochem elements led to identification of 17 carbonate and clastic facies in Asmari Formation. In the section, 6 depositional sequences were identified and labeled as sequence 1-6. The sequence limits are all of SB2 type with exception of Sequence 6 which is SB1.