Page 80 - Formation Damage during Improved Oil Recovery Fundamentals and Applications

62 David A. Wood and Bin Yuan

β s Formation damage coefficient for straining
2
q Injection rate per formation height, m /s
T Absolute temperature of reservoir, K
p The flowing pressure at different locations, Pa
Δp Pressure drop, MPa
Pressure drop along different layers 1 and 2, MPa
Δp 1;2
Total flow mobility (both water- and oil-phase)
λ t
Total flow mobility within different layers 1 and 2
λ t1;2
r Radial location of flowing system, m
Pore radius, m
r p
Outer radius of radial flowing system, m
r e
Radius of nanoparticles, m
r NP
Oil saturation
S or
Capillary number
N ca
θ Contact angle at the crude oil-formation water-porous rock interface
σ Interfacial tension (IFT) between oil and water
Interfacial tension (IFT) between oil and formation water
σ ow
Interfacial energy between oil and porous rock matrix
σ om
Interfacial energy between formation water and porous rock matrix
σ wm
σ cr;initial 0; S wc Þ Critical retention concentration of fines at initial condition with connate
ð
3
water saturation Swc, m /m 3
σ a Maximum retention concentration of particles at specific flow and salinity
conditions
σ cr Maximum volumetric concentration of captured particles
3
σ cr Maximum retention concentration of fine particles, m /m 3
3
σ s Strained fine particles concentration, m /m 3
Δσ Concentration of fine particles released
xf D Locations of water-saturation front
t D Dimensionless time or injected pore volume
γ Salt concentration; γ i is formation fluid salinity; γ o injected fluid salinity
v interstitial velocity of the displacing fluid
U Darcy velocity
Dimensionless distance
x D
REFERENCES
Aksulu, H., Hamso, D., Strand, S., et al., 2012. The evaluation of low salinity enhanced
oil recovery effects in sandstone: effects of temperature and pH gradient. Energy Fuels
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Al-adasani, A., Bai, B., 2012. Investigating low-salinity water flooding recovery mecha-
nism(s) in carbonate reservoirs. In: Proceedings of the 2012 SPE EOR Conference at
Oil and Gas West Asia, Muscat, Oman, 16 18 April, SPE155560.
Al-adasani, A., Bai, B., Wu, Y.-S., Salehi, S., 2014. Studying low-salinity waterflooding
recovery effects in sandstone reservoirs. J. Pet. Sci. Eng. 120, 39 51.
Alagic, E., Skauge, A., 2010. Combined Low Salinity Brine Injection and Surfactant
Flooding in Mixed 2 Wet Sandstone Cores. Energy Fuels 2010. Available from:
https://doi.org/10.1021/ef1000908.
Al Shalabi, E.W., Sepehrnoori, K., Delshad, M., 2013. Mechanisms behind low salinity
water flooding in carbonate reservoirs. SPE-165339-MS. SPE Western Regional &