Page 190 - Fundamentals of Enhanced Oil and Gas Recovery

178 Forough Ameli et al.

Figure 5.14 Steam-drive oil recovery mechanism.

_ m s H s M R h
A h 5 Gt D
ðÞ
4 T s 2 T R ÞαM 2
ð
ð7292Þð977Þð32:74Þð20Þ
5 0:113
4 470:9 2 80Þð0:0482Þ 31:12 2
ð
5 7222 ft 2
r ffiffiffiffiffiffi r ffiffiffiffiffiffiffiffiffiffi
7222
A h
r h 5 5 47:94 ft
π π
5.2.12 Steam Drive Oil Recovery Mechanism

The assumption of this technique is occupation of the whole area by steam. After
formation of the hot water zone, it invades to steam zone of the formation. The
other assumption is preceding the oil to each of the zones. This mechanism is illus-
trated in Fig. 5.14. Willman et al. [74] analyzed various experimental data to deter-
mine the main mechanisms of displacement by the tests conducted on long and
short cores. Tests were done at 330 and 250 F and the pressure of 800 psig. The

other output was that the required number of pore volumes of injected fluid is more
in the case of hot and cold water injectionincomparisontosteam injection. The
main issues that resulted in increased recovery of hot water include thermal expan-
sion and viscosity reduction. The residual saturation of oil in water-drive systems is
a weak function of temperature. This leads to application of fractional-flow concept
in hot water-drive systems for determining the performance of waterflood by dis-
placement calculations.

5.2.12.1 Steam Distillation
• The presence of an immiscible phase (water/steam) will lower the temperature for
the volatile organic phase to resolve. Vapor phase is in contact with two immiscible
liquids.