Sand packs, preparation

All sand packs were prepared in lucite columns approximately 6 or 12 in length and 1-1/2 in diameter. The two ends of a colunn were equipped with solid lucite plugs. Each colunnn was also equipped with a stainless steel cage to hold the assembly in place. In sand pack preparation, wire gauze and a layer of reagent grade sand were packed at each end of the column to hold the reservoir sand sample in place. The sand pack pore volumes for the 6 colunnn were approximately 50 mis, and for the 12 colunn were approximately 110 mis. The pore volume was determined gravimetrically by evacuation of the sand pack under vacuum and saturation with 1% NaCl. 

Flow Tests. One foot long sand packs using Wilmington oil field unconsolidated sand were prepared for each of the flow tests. Porosity and permeability of all the sand packs were within 30-35% and 100-300 md, respectively. All core packs were evacuated to about 1 mm of mercury (Hg) before saturating them under gravity to assure complete water saturation. Table III gives the core and fluid properties for the flow tests. The properties of the cores were chosen so that they are close to the field conditions reported by Krebs(15). 

Soo and Radke (11) also studied the effect of average droplet size of emulsion on the flow behavior in porous media. The droplet size distribution of the emulsions that were prepared with surfactants and NaOH in a blender are shown in Figure 12. These droplet size distributions were found to be log-normal distributions. Others (9, 27) have also observed that the size of emulsion droplets was log-normally distributed. Soo and Radke (11) conducted experiments with emulsions having different average mean diameter in fine Ottawa water-wet sand packs. Their results of the reduced permeability, k/ko, and reduced effluent volume concentration as a function of the pore volume of oil (in the emulsion) injected are shown in Figure 13. All emulsions were of 0.5% quality, and the initial permeability, ko, was 1170 mD (millidarcies). The lines in the figure represent results of flow theory (12,13) based on deep-bed filtration principles. 

Four 6 sand packs were prepared with Aminoil IMZ sand. 

Five sand packs were prepared with THUMS Ranger sand. The saroples were made from the same disaggregated and extracted sand described above in the Long Term Flow Study. Without any pre-treatment, the sand packs were each saturated with a complete pore volume of an alkaline solution containing either sodium hydroxide or sodium orthosilicate and 1% NaCl. The alkaline solutions were then displaced in opposite direction to that of the initial alkaline injection input with a 1% NaCl solution in twelve small periodic increments over a long period of time. Each displaced incranent was analyzed for its alkalinity. The time period between incranents was governed by the rate of alkaline consuirption. 

After the silica flour or soil mixture has set, add a layer of silica sand as a filter pack, then fill the remainder of the borehole with bentonite or a grout seal (Figure 5). Access lines may be run from the lysimeter reservoir through a protective PVC riser pipe to the land surface. A locking protective casing should be used to secure the abovegrade lysimeter components. If the lysimeter is used immediately after installation, it is necessary to purge any water used to prepare the siiica flour or soil slurry. Remove at least the water volume equivalent to approximately one third of that used to make slurry. 

Details of preparation and storage conditions for crops that last well through the winter are given here (seepanel, left). Some other crops can also be stored for shorter periods for example, carrots, parsnips, beets, rutabagas, and celeriac keep well if packed in moist sand or fine leaf mold in shallow trays or boxes. 

Mg)2(Al,Si)40io(OH)2] was prepared by sifting glauconite sand to obtain a fraction of uniform size (<40 and >70 mesh size). The sand was washed repeatedly in distilled water to remove dust adhering to the particles and was packed in a stainless-steel tube to form a column 15 cm long by 1.0 cm diameter with 53 percent porosity. 

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