Payam Alikhani - Department of Petroleum Engineering, Petroleum University of Technology, Ahwaz, Iran
SeyyedMohammadReza Hesami - Department of Gas Engineering, Petroleum University of Technology, Ahwaz, Iran
Emad Jamshidi - Drilling Department, Exploration Directorate, National Iranian Oil Company, Tehran, Iran

Enhanced Oil Recovery (EOR) process is used to recover additional oil left in place after primary recovery. The prediction of its performanceis of great importance in selection and design ofcertain EOR process and future planning for oil production. Microbial Enhance Oil Recovery(MEOR) is friendly with environment, and it isapplied as ex-situ and in-situ in oil reservoirs. In microbial flooding, in the water oil contact themicroorganisms consume the nutrition and producebioacid, biopolymer, biosurfactant, biogas and solvent, which improve the oil recovery and yield theless harmful product for a green environment with respect to other types of EOR methods. This study was investigated potential of applying MEOR by oilrecovery prediction in five different carbonate reservoirs. The study is conducted utilizing 100 laboratory data with valid references. In all of thesereferences, MEOR processes are obtained based on porosity, permeability, salinity, temperature, pressure and PH. Clostridium Acetobutylicum are also used asmicrobe. From this laboratory data different data clusters are tested by Adaptive Neuro Fuzzy Inference System (ANFIS). The best modeling (fouror five clusters) obtained based on Mean Square Error (MSE) and correction factor (R-Value) by employing reservoir parameters as inputs and oilrecoveries as outputs. Five different reservoirs selected from Iranian southern oil fields, which have not experienced any EOR processing before.Reservoir properties entered as inputs in obtained ANFIS model, which result five output as oil recovery prediction. Results reveal 36.71- 40.68% oilrecovery, which conform to previous studies. Besides, considering green technologies, it is shownthat MEOR can be one of the best options among EOR techniques for carbonate reservoirs