Identification of a new biozone within the Sarvak Formation in Binak oil field well No.2 ( NW Bushehr )

Abastract

The Binak oil field is located in an asymmetrical anticline with NW- SE Trending in NW Bushehr. The Thickness of  Sarvak Formation in well No.2 is 560 m and is mainly composed of limestone, dolomitic limestone and shale interbeds. Petrographic studies of 306 cutting thin sections led to recognition of 3 carbonate lithofacies associations and one siliciclastic lithofacies. They are deposited in three  facies belts including open marine, bar and lagoon. Based on this studies , four biozones were identified .These are including No.21(Trocholina - Orbitolina ass.zone) 25 (Nezzazata - Alveolinid ass .zone ), 26 (Oligostegina Facies) and 24  ( Rudist debris ) of Wynd (1965 ). It is noted that biozone No.24 interferces with biozone No.25 and biozone 21 has been recognized for the first time in the Binak well No.2 . Based on these data Late Albian - Turonian  age is suggested for Sarvak Formation in the study area