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• Accelerated production;
• Stepwise-Thermal flooding.
5. Combined EOR
In most cases combined EOR methods are implemented. These are
different combinations of hydrodynamic and thermal,
hydrodynamic and physicochemical, thermal and physicochemical
and other methods.
6. There are also some locally applied methods which are usually
attributed to a special group called Oil Production Intensification
methods. It would not be quite correct to associate these methods
with EOR methods since while increasing for some period of time
the current oil production (recovery) they do not usually increase
the final recovery rate as EOR methods do.
All the methods mentioned above are characterized by
varying potential of enhanced oil recovery.
For example, Russian oil recovery index using thermal
methods is about 15-30%, gas methods is around 5-15%, chemical
methods is about 25-35%, physical methods is around 9-12%,
hydrodynamic methods make 7-15% (Fig. 8.5).

Figure 8.5 - Carability of different EOR methods

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