Improving Conventional Waterflooding
Polymer flooding is best used in moderately heterogeneous reservoirs that contain viscous oils. It is most effectively applied in the early stages of waterflooding, when the mobile oil saturation is high.
Timing is critical. The greatest economic benefits of polymer flooding are realized when the polymer flood is started at initial water injection. Polymer floods later in the life of a waterflood result in the reservoir containing more water that must be produced before and during incremental oil production. Increased operating costs associated with higher producing water-oil ratios burden polymer flood economics.
The following factors will influence project design, oil recovery and waterflood efficiency:
- Well spacing and injection pattern
- Asset location (on/offshore)
- Well mechanical integrity
- Net pay definition (multiple zones)
- Reservoir temperature
- Reservoir continuity (faults, compartments, etc.)
- Injection water salinity and temperature
- Polymer characteristics and handling