EEOR in Carbonate Reservoirs - Electrokinetics for Petroleum and Environmental Engineers - page 159

100

Core - 9 - WF

80

Core - 9 - (WF + EK)

Core - 10 - WF

60

Core - 10 - (WF + EK)

Core - 11 - WF

40

Core - 11 - (WF + EK)

Core - 12 - WF

Core - 12 - (WF + EK)

20

Core - 13 - WF

Core - 13 - (WF + EK)

0

0 2 4 6 8 10 12 14

Number of injected pore volumes

Figure 4.2 Displacement Efficiency (%) versus number of injected pore volumes in
experiments conducted on a 1.5 -in core at a flow rate of 0.25 ml/min.

for EK-assisted waterflooding; about 3-4% more when compared to what
was achieved during high flow rate experiments. This is due to an extended
contact time of brine with the core plug leading to a greater migration of
the oil left in the formation pores as mentioned by Amba et al. (1965).
Furthermore, there is also continuity of a significant oil recovery in the
EK assisted waterflooding as a small pore volume is injected for a longer
period of time, effectively dragging the oil molecules along the interface of
the mobile layers.
It was observed that electrochemically enhanced reactions resulted in
an upgrade of the crude oil, while Joule heating also increased the mobility
of fluids further.

4.3 SMART (Simultaneous/Sequential Modified

Assisted Recovery Techniques)

The main objective of surfactant flooding in carbonates is wettability
alteration and the reduction of interfacial tension (IFT). For more details
on conventional surfactant-flooding, see Ziegler (1988), Wu et al. (1996),
Seethipalli et al. (2004), Manrique et al. (2004,2007), Xie et al. (2005),
Alkafeef et al. (2007), and Haiyang et al. (2011).