Page 283 - Enhanced Oil Recovery in Shale and Tight Reservoirs

260 Enhanced Oil Recovery in Shale and Tight Reservoirs

water-wet, it could imbibe into small pores (indicated by the left peak).
Similarly to the heavy water case, more heavy water with the surfactant
imbibed into the cores, and T 2 decreased.
Comparing the subfigure b and the subfigure c, the T 2 spectrum curves
became lower at the higher concentration, indicating higher concentration
resulted in more wettability alteration from oil-wet to water-wet; therefore,

(A) 2000 0
12h
24h
48h
1500 96h
192h
Amplitude 1000
240h
Water
500

0
0.01 0.1 1 10 100 1000
T relaxation time/ms
(B) 3000 (C) 3000
0 h 0 h
12 h 12 h
24 h 24h
48 h 48 h
96 h 96 h
2000 192 h 3000 192 h
240 h
240 h
Amplitude Amplitude
IAE-0.01% IAE-0.1%
1000 1000
0 0
0.01 0.1 1 10 100 1000 0.01 0.1 1 10 100 1000
T relaxation time/ms T relaxation time/ms
(D) (E)
3000 2000
0 h 0 h
12 h 12 h
2500 24 h 24 h
48 h 1500 48 h
96 h 96 h
2000 192 h 192 h
240 h
Amplitude 1500 AEO-9 Amplitude 1000 AEO-9
240 h
–0.01% –0.1%
1000
500
500
0 0
0.01 0.1 1 10 100 1000 0.01 0.1 1 10 100 1000
T relaxation time/ms T relaxation time/ms
Figure 9.33 T 2 spectrum curves during the process of spontaneous imbibition in
heavy oil and heavy water of different surfactants at two concentrations of 0.01%
and 0.1%.