Experiments on Mixing During Miscible Displacement in Porous Media

Abstract

The paper describes experiments on miscible displacement in various porous media and the results of these experiments. Both glass bead packs and natural cores were used. Bead diameters varied from 0.044 to 0.47 mm, and pack lengths varied from 83 to 678 cm. Natural cores used were Berea and Torpedo sandstone.By taking samples as small as 0.5 cc and using refractive index for analysis, the data on breakthrough curves could be plotted to within ± 0.5 per cent. To plot the data correctly on error function paper, a parameter (Vp -V)/y'V was used which allowed for the predicted growth of the front as it moved past the observer.The change in the amount of mixing (length of mixed zone) was studied by varying velocity, length of travel, bead size, viscosity ratio and pack diameter. When the displaced material was less viscous than the displacing material (favorable viscosity ratio), these changes were adequately predicted by theory. When natural cores were used, rath'er than glass beads, the amount of mixing was greatly increased -also qualitatively predicted by theory.In experiments with favorable viscosity ratios in which the ratio was varied from 0.175 to 0.998, it was found that the rate of mixing was changed by a factor of 5.7. Thus, the rate of mixing is strongly affected by viscosity ratio, even when the theoretical error function relationship for mixing is valid.Experiments using. fluids with viscosity ratios near 1.0 showed that the instability effects of even a slightly unfavorable viscosity ratio (1.002) caused disproportionately m 0 r e elongated breakthrough curves than found with a favorable viscosity ratio (.998). When the viscosity ratio was as high as 5.71 these instability effects were much more pronounced, as evidenced by the shape of the breakthrough curve. The displacements at viscosity ratios above 1.0 no Original manuscript received in Society of Petroleum Engi~ neers Office Nov. 30, 1959. Revised manuscript received Oct.

Quantifying solute spreading and mixing in reservoir rocks using 3-D PET imaging

“…While some studies (Hulin & Plona 1989;Gist et al 1990) report measured dispersivity values for Berea sandstone that are just above those obtained in this work, others have reported significantly larger values (e.g. 0.2-0.5 cm) (Brigham et al 1961;Perkins & Johnston 1963;Baker 1977;Walsh & Withjack 1994). We argue that such discrepancy is a direct manifestation of subcore-scale heterogeneities of rock samples and, specifically, of their spatial distribution and correlation length that may vary from sample to sample even when the same rock type is considered.…”

“…(+) Dullien (1992) and (×) Perkins & Johnston (1963), as well as those on Berea sandstone samples, i.e. ( @ ) Brigham et al (1961), ( D ) Scheidegger (1974) (after Cortis & Berkowitz (2005)), ( C ) Baker (1977), ( A ) Hulin & Plona (1989), ( E ) Gist et al (1990) and (♦) Honari et al (2015). Results from this study are given by the black-filled symbols, as obtained from the 'tuned streamtubes' ( u ) and '2P-ML' ( q ) models and by assuming D = 1 × 10−5 cm 2 s −1 and d P = 150 µm.…”

“…grain) size. So-called 'inhomogeneity factors' have been introduced to account for this increased dispersivity when using the Fickian advection-dispersion model described above (Brigham, Reed & Dew 1961;Perkins & Johnston 1963). Not surprisingly, this empirical approach seems to work only in a limited number of instances (Honari et al 2015), while for most consolidated systems only a poor fit of the tracer elution history is achieved (Donaldson, Kendall & Manning 1976;Baker 1977).…”

Colloid-Facilitated Transport of Radionuclides Through The Vadose Zone

“…We attribute the humps to the breakthrough of distinct viscous fingers. The main features of the breakthrough curves, early breakthrough, humps, and slow approach of inflow concentration caused by flow instability, have been reported previously for miscible displacement experiments in porous media using fluids of different viscosity [Brigham et al, 1961]. [22] Horizontal displacement of the high ionic strength solution by the low ionic strength solution also resulted in an unstable front, but the effect was not very pronounced in our experiments (Figure 1f).…”

Experimental and numerical investigations into the effect of heterogeneities on the recovery of heavy oil by VAPour EXtraction (VAPEX)

“…The absolute permeability of the different beads, meanwhile, was simply calculated from Darcy' Law by measuring the pressure difference across the inlet and outlet of the pack using pressure transducers while varying the injection rates. The longitudinal dispersion coefficient for each bead size was determined using the method of [47] from effluent profiles resulting from vertical upwards, glycerol-ethanol displacements in the mini-pack [48]. These displacements were performed at the same injection rates as used in the VAPEX experiments.…”