Page 157 - Primer on Enhanced Oil Recovery

Chemical EOR 147

Figure 12.4 Polymer flooding application criteria.

Oil viscosity should preferably not to exceed 150 cP or be lower than 10 cP
API gravity should be more than 13.
The permeability of the rock should preferably be above 10 mD.

Formation temperature: a low formation temperature is preferred, preferably less than

80 C and no higher than 100 C.

Use wells with high injectivity and with an additional injection pressure boost.
The clay content in the reservoir should be low.
Low salinity of injected and formation water is greatly preferred.
Polymer flooding is usually successful in sand formations, but there have been
known successful applications in carbonate and fractured reservoirs. It is preferable
to use polymer flooding in layered heterogeneous as well as micro-inhomogeneous
formations.
It is preferable to use the method in hydrophilic formations, but there are known
cases of successful use in hydrophobic and mixed wettability formations.

12.1.2 Polymer flooding completed projects
Starting from the 60s of the last century the active introduction of polymer flooding
began As can be seen from Fig. 12.5, currently at around 730 projects have been
implemented in 24 countries. At the same time, the absolute leaders here are the
United States, where around 560 projects have been implemented, i.e. approxi-
mately 76% of all implemented projects.