1. D = diffusion coefficient, cm2/s
  2. C = concentration, g/cm3
  3. Co= initial concentration, g/cm3
  4. c = compressibility, psi-1[Pa-1]
  5. Fr = resistance factor (brine mobility before placement of blocking agent divided by blocking-agent mobility before setting or gelation)
  6. Fr1 = resistance factor in Zone 1, Core 1, or Fracture 1
  7. Fr2 = resistance factor in Zone 2, Core 2, or Fracture 2
  8. Frr = residual resistance factor (mobility before placement of blocking agent divided by mobility after placement of blocking agent)
  9. Frr1 = residual resistance factor in Zone 1
  10. Frr2 = residual resistance factor in Zone 2
  11. Frro = oil residual resistance factor
  12. Frrw = water residual resistance factor
  13. G = gravity number
  14. g = acceleration of gravity, ft/s2 [m/s2]
  15. h = formation thickness, ft [m]
  16. I = injectivity, bbl/D-psi [m3/s-Pa]
  17. Io = initial injectivity, bbl/D-psi [m3/s-Pa]
  18. k = permeability, md [m2]
  19. ki = permeability in Zone i or direction i, md [m2]
  20. k1 = permeability in Zone 1, md [m2]
  21. k2 = permeability in Zone 2, md [µm2]
  22. L = distance or gelant or gel bank length, ft [m]
  23. Lm = length of the mixing zone, ft [m]
  24. mH = slope from Hall plot, psi-D/B [Pa-s/m3]
  25. PV = pore volume
  26. p = pressure, psi, [Pa]
  27. pe = pressure at the external drainage radius, psi [Pa]
  28. pwo = initial pressure at the wellbore, psi [Pa]
  29. pw2 = final pressure at the wellbore, psi [Pa]
  30. p = pressure drop, psi [Pa]
  31. q = volumetric injection or production rate, bbl/D [m3/s]
  32. r = radius or pore radius, ft [m]
  33. re = external drainage radius, ft [m]
  34. rp = radius of penetration, ft [m]
  35. rpi = radius of penetration into Layer i, ft [m]
  36. rp1 = radius of penetration into Layer 1, ft [m]
  37. rp2 = radius of penetration into Layer 2, ft [m]
  38. rw = wellbore radius, ft [m]
  39. s = skin factor
  40. t = time, s
  41. tg = gelation time, s
  42. ttr = transient time, s
  43. u = superficial or Darcy velocity or flux, ft/d [cm/s]
  44. uz = vertical superficial velocity, ft/d [cm/s]
  45. α = dispersivity, cm
  46. = fluid viscosity, cp [mPa-s]
  47. o = oil viscosity, cp [mPa-s]
  48. p = gelant viscosity, cp [mPa-s]
  49. w = water viscosity, cp [mPa-s]
  50. ó = standard deviation, m
  51. Ø = porosity
  52. Øi = effective aqueous-phase porosity in Zone i
  53. Ø1 = porosity of Zone 1
  54. Ø2 = porosity of Zone 2
  55. Θ = dip angle relative to horizontal
  56. ρ = density, g/cm3
  57. Δρ = density difference, g/cm3