Page 233 - Formation Damage during Improved Oil Recovery Fundamentals and Applications

Using Nanofluids to Control Fines Migration in Porous Systems 207

• The maximum retention concentration of fine particles onto rock
grains is dependent upon both water quality and flow velocity during
low-salinity waterflooding. Nanofluid treatment prior to low salinity
water injection can help control fines migration adjacent to injection
wells, and significantly maintain long-term well injectivity, but with the
negative consequence of accelerated breakthrough of injected water.

NOMENCLATURE

C NP Volumetric concentration of nanoparticles with respect to pore volume,
3
m /m 3
Volumetric concentration of nanoparticles with respect to pore volume,
C FP
3
m /m 3
3
Injected nanoparticles concentration with respect to pore volume, m /m 3
C NP, inject
3
Injected fine particles concentration with respect to pore volume, m /m 3
C FP, inj
3
Initial fine particles concentration with respect to pore volume, m /m 3
C FP, ini
3
Effluent fine particles concentration with respect to pore volume, m /m 3
C FP, eff
^ C NP Concentration of adsorbed nanoparticles with respect to bulk volume,
3
m /m 3
Concentration of straining nanoparticles with respect to pore volume,
S NP
3
m /m 3
σ NP Concentration of retained nanoparticles with respect to bulk volume,
3
m /m 3
S a ,S FP Concentration of straining nanoparticles with respect to pore volume,
3
m /m 3
σ NP ; σ a Concentration of retained nanoparticles with respect to bulk volume,
3
m /m 3
λ s Particles straining filtration coefficient
λ ad Nanoparticles adsorption filtration coefficient
λ a Fine particles attachment filtration coefficient
β a Formation damage coefficient related to particles adsorption
β s Formation damage coefficient related to particles straining
L Length of core plug
A Cross-section area of core plug
3
σ NP;max1 Maximum total retention concentration of nanoparticles, m /m 3
3
σ NP;max2 Maximum irreversible retention concentration of nanoparticles, m /m 3
Fluid injection rate, mL/min
q inj
Electrostatic forces, N
F e
Electrostatic forces at the initial condition, N
F ei
Langmuir adsorption constant of nanoparticle
K NP
T Absolute temperature of reservoir, K