Untitled - Technische Universiteit Eindhoven

More documents

Recommendations

Info

8.4. Results and discussion 1230.150.150.10.1w wSA × Sw [-]w wSA × Sw [-]0.050.05time0-0.03 -0.02 -0.01 0 0.01 0.02 0.03z [m]time0-0.03 -0.02 -0.01 0 0.01 0.02 0.03z [m]Fig. 8.4: Profiles of the amount of formed silicic acid (SA). Two PV of TMOS/oil were injectedbetween t = 0 and t = t s . The time step between different solid curves is 0.8 hours.The dashed curve is the saturation profile at t = t s . (left) Q = 1 ml min −1 . (right)Q = 0.02 ml min −1 .the amount of gel that can be formed. The product of the wwSA and S w represents thisamount, and the profiles are shown in Figure 8.4. The fast placement of the batch resultsin a gradual and uniform increase in the course of time of the amount of SA from zeroto about 0.105. The slow placement results in a slightly non-uniform distribution but ahigher amount of silicic acid formed (ww SA × S w ≈ 0.125).8t=08t=07time7time6655E [-]4E [-]43322110-0.03 -0.02 -0.01 0 0.01 0.02 0.03z [m]0-0.03 -0.02 -0.01 0 0.01 0.02 0.03z [m]Fig. 8.5: Profiles of the partition term E. Two PV of TMOS/oil were injected between t = 0and t = t s . The time step between different solid curves is 0.8 hours. The dashedcurve is the saturation profile at t = t s . (left) Q = 1 ml min −1 . (right) Q = 0.02 mlmin −1 .The effect of the methanol concentration on the partitioning of TMOS between bothphases is illustrated by the profiles of the partitioning coefficient E = exp(ε/R g T ), whichare shown in Figure 8.5. It can be observed that initially E is much larger than one, so
124 8. Model of reactive transport of an oil-soluble chemical in porous mediathat the TMOS tends to remain in the oleic phase. However, E decreases as the methanolconcentration is increased. Ultimately, E is about 0.8. It is noted that the values for Edepend on the choice of ε 0 and a, both of which are arbitrary at this point. In the followingsection these parameters are varied and the results are discussed.Finally, from the simulated profiles of w T o the volume fractions φ T of TMOS in oil –at five different positions (slices) along the core – were derived and plotted against time(indicated by the solid curves in Figure 8.6). The purpose is to compare, qualitatively, thecalculated concentration profiles with the experimentally derived concentration profiles(see also Chapter 6). Direct quantitative comparison with the experimental profiles isnot plausible due to a number of uncertain parameters and due to the uncertainty in themeasured profiles.0.20.180.160.14A03 (no buffer)z = -25 mmz = -12.5 mmz = 0 mmz = 12.5 mmz = 25 mm0.20.180.160.14A05 (pH = 2.84)k = 1.39 x 10 -3 s -1z = -25 mmz = -12.5 mmz = 0 mmz = 12.5 mmz = 25 mm0.120.12φ T[-]0.1φ T[-]0.10.08z (solid curves)0.080.060.060.040.02k = 3.23 x 10 -4 s -1 0 5 10 15 200.040.02z (solid curves)00 5 10 15 20time [h]0time [h]0.20.180.160.14A07 (pH = 6.2)z = -12.5 mmz = 0 mmz = 12.5 mmz = 25 mm0.20.180.160.14A09 (pH = 9.48)k = 8.8 x 10 -5 s -1z = -25 mmz = -12.5 mmz = 0 mmz = 12.5 mmz = 25 mm0.120.12φ T[-]0.1φ T[-]k = 3.2 x 10 -5 s -1 0 5 10 15 200.10.080.080.060.060.040.040.020.0200 5 10 15 20time [h]0time [h]Fig. 8.6: Measured concentration profiles in the core injection experiments (see also Chapter6) for the different slice positions indicated by the symbols. The solid curves are thesimulated concentration profiles. The reaction constants k are displayed in the graphsand are based on the bulk experiment results. The other parameters are defined inSections 8.4.1 and 8.4.2.The experiments performed at 25 ◦ C are considered. For the simulations the reactionconstants k are based on the values obtained from the bulk experiments (see Chapter4). As was discussed in Chapter 6 the experimentally determined concentration profiles
Page 2:
TWO-PHASE REACTIVE TRANSPORTOF AN O
Page 5 and 6:
Dit proefschrift is goedgekeurd doo
Page 7 and 8:
4. The effect of pH on mass transfe
Page 9 and 10:
Samenvatting . . . . . . . . . . .
Page 11 and 12:
2 1. Introductionproducerbarrierlow
Page 13 and 14:
4 1. IntroductionTwo inter-European
Page 16:
Part ITwo-phase bulk systems7
Page 19 and 20:
10 2. Coupled mass transfer and sol
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
32 3. Interfacial effects during re
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
0+,44 4. The effect of pH on mass t
Page 55 and 56:
46 4. The effect of pH on mass tran
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
58 5. Cross-linking of silica with
Page 69 and 70:
Page 71 and 72:
0+,62 5. Cross-linking of silica wi
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82: 72 5. Cross-linking of silica with
Page 84: Part IIGel placement in porous mate
Page 87 and 88: 78 6. Coupled mass transfer and gel
Page 107 and 108: 98 7. Permeability reduction in por
Page 109 and 110: 100 7. Permeability reduction in po
Page 123 and 124: 114 8. Model of reactive transport
Page 131: 122 8. Model of reactive transport
Page 141 and 142: 132 9. Concluding remarks and outlo
Page 149 and 150: 140
Page 151 and 152: -142 Appendix A, - C D *, - D
Page 153 and 154: 144 Appendix Awhere S 0 is a consta
Page 155 and 156: 146 Appendix AThe 0.95 Tesla scanne
Page 157 and 158: 148 Appendix B
Page 159 and 160: 150 Appendix CwhereΩ A (θ) = −2
Page 161 and 162: 152 Appendix C
Page 163 and 164: 154 Appendix D
Page 165 and 166: 156 Appendix Eand equal to zero in
Page 167 and 168: 158 Appendix EAs the saturations, d
Page 169 and 170: 160 Bibliography[12] B. Vinot, R. S
Page 171 and 172: 162 Bibliography[40] M. D. Mantle a
Page 173 and 174: 164 Bibliography[70] F. J. M. van d
Page 175 and 176: 166 Bibliography[97] K. Yoshida, A.
Page 177 and 178: 168 Bibliography[127] G. W. Scherer
Page 179 and 180: 170 Bibliography
Page 181 and 182: 172 Summaryand gelation rates. The
Page 183 and 184:
174 Samenvattingwaterfase. De T 1 v
Page 185 and 186:
176 List of publications
Page 187 and 188:
178 Dankwoordimmer opgewekte stemmi
Page 189:
Prior to the speech, Harald Cramér
show all

Untitled - Technische Universiteit Eindhoven

Create successful ePaper yourself

Delete template?

Save as template?