Page 429 - Enhanced Oil Recovery in Shale and Tight Reservoirs

Fracturing fluid flow back 397

Baseline (DI-Water) – Coreflood #4 1wt% Surf (Type-I) – Coreflood #5
0.8 0.8
End of Invasion 0.7 End of Invasion
0.7
Water Saturation in Core 0.5 0.367PV (11hr) Water Saturation in Core 0.5 0.367PV (11hr)
0.033PV (1hr)
0.017PV (0.5hr)
0.033PV (1hr)
0.167PV (5hr)
0.6
0.6
0.167PV (5hr)
0.333PV (10hr)
0.533PV (16hr)
0.467PV (20hr)
0.800PV (24hr)
0.800PV (24hr)
0.4
0.4
0.3
0.3
0.2
0.1 0.2
0.1
0.0 0.0
0 50 100 150 200 0 50 100 150 200
Distance from Frac Face (mm) Distance from Frac Face (mm)
Baseline (DI-Water) – Coreflood #6 1wt% Surf (Type-II) – Coreflood #7
0.8 0.8
End of Invasion
0.7 End of Invasion 0.7 0.017PV (0.5hr)
0.017PV (0.5hr)
Water Saturation in Core 0.5 0.267PV (8hr) Water Saturation in Core 0.5 0.533PV (16hr)
0.100PV (3hr)
0.100PV (3hr)
0.6
0.6
0.167PV (5hr)
0.167PV (5hr)
0.267PV (8hr)
0.367PV (11hr)
0.533PV (16hr)
0.4
0.4
0.3
0.3
0.2
0.1 0.2
0.1
0.0 0.0
0 50 100 150 200 0 50 100 150 200
Distance from Frac Face (mm) Distance from Frac Face (mm)
Baseline (DI-Water) – Coreflood #1 1wt% Surf (Type-III) – Coreflood #3
0.8 0.8
End of Invasion End of Invasion
0.7 0.350PV (10.5hr) 0.7 0.033PV (1hr)
Water Saturation in Core 0.5 0.467PV (14hr) Water Saturation in Core 0.5 0.467PV (14hr)
0.033PV (1hr)
0.167PV (5hr)
0.167PV (5hr)
0.6
0.6
0.350PV (10.5hr)
0.933PV (28hr)
0.850PV (25.5hr)
1.167PV (35hr)
0.4
0.4
0.3
0.3
0.2
0.1
0.1 0.2
0.0 0.0
0 50 100 150 200 0 50 100 150 200
Distance from Frac Face (mm) Distance from Frac Face (mm)
Figure 12.54 Comparison of changes of water saturation profile during flow back and
hydrocarbon production among DI water and various surfactant cases (Liang et al.,
2017a).
than the type I. Liang et al. (2017a) explained that the low efficiency of the
type II was not caused by the fact that water was dispersed in water-in-oil
microemulsion; rather it was easier for oil to bypass the type II microemul-
sion. However, such explanation is not supported by conventional reasoning