Abstract: Re-understanding of underground geologic system is one of the key technologies for secondary development of old oilfields,while geological modeling is the only way to quantitatively re-understand geologic system of reservoirs.Old and complex fault block oilfields are characterized by long history of exploitation,complex structures,large lateral variation of reservoirs,and local enrichment of remaining oil.In viewing of these features,we proposed corresponding strategies and methods of geologic modeling.According to the characteristics that many faults crosscut each other,the idea of stepwise simulation-key horizon controlling-overall structural modeling was adopted to accurately and efficiently build fine structure models.In order to approximate the "real" microfacies simulation,multiple iterations microfacies modeling technology under dual vertical and lateral geological trend constraints is adopt to ensure the maximum approximation of subsequent attribute models with the 'real' geological parameters distribution of reservoirs.Meanwhile,for the key potential oil-bearing sandbodies,configuration fine modeling technology that use different stochastic simulation methods in a nested way and performs simulation step by step was used to rapidly build geologic models.This new geological modeling technology was successfully applied to the secondary development of Gangdong oilfield.

Key words: key horizon controlling, dual geological trend constraint, configuration modeling, complex fault block, secondary development, Gangdong oilfield