Effect of oil viscosity

The effect of oil viscosity on initial emulsion viscosity is not clear from these experiments. The St. Lina crude is about six times as viscous as the California crude. The apparent viscosity of the lower viscosity St. Lina Crude emulsion (2 x 10 moles NaOH/gram oil) is less than 50% greater than the lowest viscosity moderately stable California crude emulsion (4.0 x 10 NaOH). The average particle size of the St. Lina emulsion is 7 microns while that of the Shell crude emulsion is about 3 microns (see Figure 8). Since particle sizes, particle size distributions and types of oil are different, no conclusions can be drain about the influence of oil viscosity. There is, however one fact which should be emphasized, namely that viscosities 600 times lower than that of the crude were observed for 60% St. Lina crude emulsions. 

Figure 36. Effect of oil viscosity on the half-lifetime (r ) of foams formed from 0.06 M sodium dodecyl sulfate in the presence of 200ppm mixed antifoam containing silicone oils [poly(dimethylsiloxane), DMPSJ of various kinematic viscosities and 2.5 wt% hydrophobized silica (T-500).

Figure 10. Effect of Oil Viscosity on Oil Displacement Efficiency by Foam Flooding.

The effect of oil viscosity on the displacement of oil is presented in Figure 10. In order to determine the oil displacement efficiency by foam flooding, the injection of gas phase was started at surfactant solution breakthrough. Both air and steam were employed to generate in-situ foams. The steam foam recovered more oil as compared to air foams. 

The effect of oil viscosity on fluid displacement efficiency for both pure and commercial surfactants is shown in Figure 10. It was cbserved that the oil viscosity has an effect on the fluid displacement... 

There is little experimental evidence in the scientific literature concerning the existence of this supposed optimum. Indeed there have apparently been few published studies of the effect of oil viscosity on both the effectiveness and deactivation rates of hydrophobed silica-polydimethylsiloxane antifoams. Evidence that increase in polydimethylsiloxane oil viscosity can reduce the rate of deactivation of hydrophobed silica-oil antifoams is, for example, presented by Racz et al. [3]. These authors repeatedly pulled films, using a film frame, from surfactant solution upon which antifoam had been spread. The time for film rupture was measured. After several hundred films had been pulled, the film rupture time increased dramatically indicating partial antifoam deactivation. Increase in the viscosity of the oil in a hydrophobed silica-oil antifoam, from 200 to 1000 cSt, increased the number of films that could be pulled by more than 50%, implying a decrease in rate of deactivation [3]. 

The latter argnment is of course speculative and we are therefore forced to conclude from these limited studies that the effect of oil viscosity on hydrophobed silica-polydimethylsiloxane antifoam effectiveness and rate of deactivation is not fully understood. Clear evidence of an optimum viscosity, as suggested by Denkov et al. [6], is lacking as is the magnitnde of the viscosity before the supposed onset of... 

Figure 5. Effect of oil viscosity on the net recovery efficiency of smooth and grooved drum skimmer with different geometrical properties (1 mPa-s = 1 cP) (the viscosities given here, are just some examples to show the various trends of oil recovery rate versus viscosity the viscosity of weathered oils may be quite larger than these values) (Broje Keller 2006).

The most commonly utilised and versatile lubricants are mineral oils. Viscosity is the main oil characteristic. The effect of oil viscosity grade on bearing operating limits was considered in [7]. From the point of view of minimal power loss and pad temperature thinner oils are recommended at high speeds. Thicker ones are usually used at low speeds to avoid too thin oil films. 

The effect of water temperature variation is logarithmically correlated with dispersant effectiveness [585]. Dispersant/oil ratios greater than approximately 1 40 or 1 60 result in a low dispersant effectiveness. Dispersion experiments were conducted to investigate the effects of oil composition. The effectiveness is positively and strongly correlated with the saturate concentration in the oil and is negatively correlated with the contents of aromatic, asphaltene, and polar compounds in the oil. The effectiveness is weakly correlated with the viscosity of the oil. The dispersant effectiveness is limited primarily by the oil composition. 

SMD = A.T y. Q-6 AL a l(smGpLVl))n Derived from fan spray data of water and oil based on a simplified sheet breakup theory Effect of liquid viscosity not included Dombrowski Munday [94]... 

Porter and Lammerink (1994) studied the density of coriander essential oil over the temperature range 20 to 60°C. The density of the oil decreased as temperature increased. There was some variation between oils in the temperature coefficients with the change in density. The density differentials between oil and water and their temperature coefficients varied markedly between different oils. A preliminary separation coefficient is used to indicate the effect of oil density and condensate water viscosity on oil separation at different temperatures. Separation of less dense oils with small differentials would benefit more from increased temperatures than less dense oils with large differentials (C. sativum). It was necessary to use both density and viscosity data to determine whether temperature control of a separator was required to obtain efficient separation of an oil from the condensate stream following steam distillation. 

Effects of Fuel Viscosity and Pressure on Spray Formation. Atomizer is Delavan 90A, 2 gph and Fuel is No. 6 Oil. 

The effect of the viscosity of the continuous phase was studied theoretically in o/w emulsions containing water-soluble stabilizers and also in w/o emulsions of various oils [32]. In the former, droplets were larger in the absence of a stabilizer than in its presence. However, there was no clear-cut correlation of the viscosity of the continuous phase with droplet size. This can be ascribed to the increased amount of energy dissipated in the immediate vicinity of the droplets relative to the bulk liquid, which may result in more efficient disruption than if the energy dissipation occurs evenly throughout the continuous phase. The addition of a stabiiizer possibly alters and partly suppresses cavitation in the bulk liquid, the cavitation threshoid and viscosity being related similarly as in pure liquids [58]. The energy may subsequently dissipate preferentially at the surface of droplets and result in more efficient use in terms of droplet disruption. 

Kerosene is a good solvent for use with ICP-AES but is prone to noisy plasma. The solvent tetralin (1,2,3,4-tetrahydronaphthalene) has been used by workers involved in metal analysis of crude and lubricating oils with success. The solvent decalin (decahydronaphthalene) was also found to be a good solvent for metal analysis of crude oils but it is very expensive and not used extensively. The analytical performance of these solvents was studied for stability over an extended period of time to determine the effect of varying viscosities. The solvents toluene and xylene are also good solvents for dissolution but have high background to noise ratio and will not be discussed further. 

Table 7.5 Results of analysis of effects of low viscosity lubricating oil (Conostan 20) spiked with and without enhancing agents for the analysis of 0.5 (igmC1 of each metal against standard calibration curves, similar to Figure 7.13. All analyses were carried out using scandium as internal standard. Nl, no increase in signal...

Brooks, B.W. Richmond, H.N. Phase inversion in non-ionic surfactant-oil-water systems. III. The effect of oil phase viscosity on catastrophic inversion and the relationship between the drop size present before and after catastrophic inversion. Chem. Eng. Sci. 1994, 49, 1843-1853. 

Although the pour point test is still included in many specifications, it is not designated for high-boiling fuel oil (ASTM D 396). In fact, although the failure to flow at the pour point normally is attributed to the separation of wax from the fuel oil (in the case of waxy crude oil precursors), it also can be due to the effect of the viscosity of the fuel oil (in the case of naphthenic crude oil precursors). In addition, the pour point of fuel oil may be influenced by the previous thermal history of the fuel oil. Thus the usefulness of the pour point test in relation to fuel oil, especially residual fuel oil, may be open to question. 

Further data on the effect of interfacial viscosity on emulsion stability and its subsequent effect on oil recovery efficiency by alkaline water flooding are needed. 

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