Page 12 - Hybrid Enhanced Oil Recovery Using Smart Waterflooding

4 Hybrid Enhanced Oil Recovery using Smart Waterflooding

(A)

R im (% OOIP) 40

30
20
10
0
1 10 100 1000 10000 100000
__ ______ t __
(B) μ μ L 2 c
w o
100
90
80
70
60
50
40
30
20
10
0
0 2 4 6 8 10 12
Injected brine volume, PV
FIG. 1.4 Effects of connate brine concentration on recovery of Dagang crude oil (RB ¼ Dagang brine): (A)
spontaneous imbibition and (B) waterflood. (Credit: From Tang, G. Q., & Morrow, N. R. (1997). Salinity,
temperature, oil composition, and oil recovery by waterflooding. SPE Reservoir Engineering, 12(04), 269e276.
https://doi.org/10.2118/36680-PA.)

This study clearly demonstrated that the low-saline waterflooding and imbibition test are carried out using
brine has a positive effect on both wettability and water- nontreated and fired/acidized sandstones (Fig. 1.5).
flood efficiency and oil composition also affects them. Firing and acidizing treatments stabilize the fine
Therefore, this study concluded that the wettability particles in cores. In addition, the experiments also
is a complex characteristic, which responds to the test crude and refined oils to validate the effects of crude
changes of brine composition, temperature, and oil oil composition, which is observed in the previous
composition in thermodynamic condition. study of Tang and Morrow (1997). The sandstone cores
Further study (Tang & Morrow, 1999) was continued of Berea, Bentheim, CS, and Clashach are saturated with
to reveal how low-saline brine increases the crude oil synthetic reservoir brine and flooded with various
recovery. In this study, the increasing oil recovery with diluted versions of synthetic brine and seawater. The
a decrease in salinity is assumed to be attributed to results of waterflooding and imbibition test, using
the fine particle. To verify it, the comprehensive nontreated cores and crude oils, report the oil recovery