Page 126 - Primer on Enhanced Oil Recovery

116 Primer on Enhanced Oil Recovery

Figure 10.21 Hydrocarbon flooding EOR projects operating worldwide between 1969 and
2014.

additional oil. In this case, the calculation of the volume of injected gas is carried
out with consideration for the reservoir pressure and temperature.
The injected gas rate is determined as follows:

V ig 5 V o 1 V w 1 V g ;

3
where: V ig is volume rate injected gas at the reservoir conditions, m /day; V o is
3
volumetric flow rate of produced oil at reservoir conditions, m /day; V w is volumet-
3
ric flow rate of produced water at reservoir conditions, m /day; V g is volumetric
flow rate of free produced gas at reservoir conditions (V g . 0 only in the case of
production wells operation with an accidental gas breakthrough from the gas cap
3
into the production well), m /day.
The parameters included in the above equations are determined by the formulas:
V o 5 V od b o
;
V w 5 V wd b w
where, V od and V wd are volumes of oil and water after degassing (under standard
3
conditions), m / day; b o ; b w are volumetric coefficients of oil and water at reservoir
conditions.
It can be that there is a enough of hydrocarbon gas on the site itself. In this case,
gas need to be prepared locally for the injection. The gas is cleaned from