Page 215 - Formation Damage during Improved Oil Recovery Fundamentals and Applications

Using Nanofluids to Control Fines Migration in Porous Systems 189

Figure 4.5 Comparison of fines effluent concentration history obtained from analyti-
cal models (solid line, Yuan et al., 2017b; 2018b) and laboratory experimental results
(discrete points, Arab and Pourafshary 2013) for types of nanoparticles utilizations to
control fines migration.

Within the time range from 1.0 to 1.13, due to the nanoparticle effects,
there is no fines production at the outlet (C FP;eff 5 0), i.e., the rock grains
with the effects of nanoparticles have retained all newly injected fine par-
ticles. After t D1 5 3:3, the maximum retention capacity of rock grains
(with respect to fines) is reached; as a result, the newly injected fines can-
not be attached onto the rock grains anymore. From that point, the
3
3
injection-condition state (C FP;inj 5 0:02m =m ) spreads over the whole 1-
D permeable medium, and the effluent concentration of fines also
3
3
increases gradually to also reach 0.02 m /m (i.e., the injection condi-
tion). The optimal usage of nanoparticles should be the amounts that
have been injected before t D3 5 3:3, which is about 0.001 pore volume in
total (i.e., a very small relative quantity). It is worth mentioning that the
shadowed envelop ABCD in Fig. 4.6A represents the cumulative reduc-
tion quantity of fines production attributed to nanoparticle effects.
Scenario II demonstrates that before the breakthrough of injected fines
at t D1 5 1:0, there are no fines produced at the outlet. Even after the
breakthrough of injected fines, due to the positive effects of nanoparticle
adsorption, there is an extended production period with very small
amounts of fines (close to zero) produced at the outlet, as shown in