Reservoir drive mechanism is the manner in which various energy sources in a reservoir provide energy to flow fluids in reservoir to surface. Recovery of reservoir fluid is categorized into three categories (primary, secondary, and tertiary recover).
This is the first mechanism which is carried out by natural energy in a reservoir.
Figure 1 – Primary Recovery
This recovery is conducted by adding extra energy into reservoir for instant gas injection, water flood, etc. The extra energy is used to maintain reservoir pressure so a reservoir can produce effectively and yield more of a recovery factor.
Figure 2 – Secondary Recover
Tertiary Recovery or Enhance Recovery is referred to as various methods to increase oil recovery. For example, a stream injection, carbon dioxide injection, polymer injection, etc. This recovery may change rock properties or inject non-reservoir gas to enhance efficiency of the ultimate oil recovered. Normal water or reservoir gas injection is not classified in this category. This is normally performed after the secondary recovery. However, in some areas, the tertiary recovery may be started after the primary recovery.
Figure 3 – Tertiary Recovery