Abstract: Carbonate reservoirs in northeastern Sichuan area are characterized by strong heterogeneity,low matrix porosity and complicated lithology.By use of conventional logs,there existed great limitations on reservoir type classification and reservoir evaluation.Through conventional logging,imaging logging and abundant core analysis data,the lithology was identified.Based on the unique advantage on fracture and aperture evaluation of FMI imaging logs,the fracture type and the fracture occurrence were analyzed and determined,and the effect of acidification on reservoirs effectiveness was studied.Through comprehensive analysis of the carbonate reservoirs in northeastern Sichuan area,the evaluation criteria of different reservoir types were established.