With growing global energy demand and depleting reserves, enhanced oil recovery (EOR) from existing or brown fields has become more and more necessary and important. Among the various enhanced oil recovery methods, chemical EOR has drawn increasing interest from many petroleum companies. In this paper, the popular EOR methods are introduced briefly. Next, we also consider the EOR processes of chemical flooding and the screening criteria for chemical EOR processes in detail. Finally, based on the data of the White Tiger (Bach Ho) field, we evaluate and predict the potential of using chemical EOR at the main different petroleum reservoirs from the Miocene, Oligocene to fractured basement formations.