Tertiary Oil Recovery

Tertiary oil recovery refers to the process of producing liquid hydrocarbons by methods other than the conventional use of reservoir energy (primary recovery) and secondary recovery schemes discussed in the last section. In this text, tertiary oil recovery processes will be classified into three categories: (1) miscible flooding processes, (2) chemical flooding processes, and (3) thermal flooding processes. The category of miscible displacement includes single-contact and multiple-contact miscible processes. Chemical processes are polymer, micellar polymer, alkaline flooding, and microbial flooding. Thermal processes include hot water, steam cycling, steam drive, and in situ combustion. In general, thermal processes are applicable in reservoirs containing heavy crude oils, whereas chemical and miscible displacement processes are used in reservoirs containing light crude oils. The next few sections provide an introduction to these processes. If interested, the reader is again referred to several good references on the subject that provide detailed design criteria.^6,7,16–20