Page 63 - Formation Damage during Improved Oil Recovery Fundamentals and Applications

Low-Salinity Water Flooding: from Novel to Mature Technology 45

Figure 2.13 Water saturation profiles along each layer at different moments (t D 5
0.1, 0.2, and 0.3).

speed of the waterflood-front and the fraction of injection fluids flowing
into the high-permeability layer decreases gradually, until it reaches the
same as the fraction of injected fluids entering the low-permeability layer.
As low-salinity waterflooding continues, the flow fractions of the injected
water entering each layer and the movement of flood-front along each
layer gradually become uniform. This uniformity of flood-front move-
ment is attributed to the mobility control assisted by fines migration.

2.7 FACTORS INFLUENCING EOR IN SANDSTONE
RESERVOIRS SUBJECTED TO LSWF

The concept of a CRC above which the effects of LSWF would
not be realized was introduced by Khilar and Fogler (1984) as shown in
Fig. 2.14.
Salehi et al. (2017) conducted an experimental study on a sandstone
core from the Cheshme Khosh oil field (Iran). The system tested
involved:
• Core with porosity 14.19% and permeability 20.8 mD;
• Formation water salinity B200,000 ppm;