Salinity viscosity affected

Each oil-dispersant combination shows a unique threshold or onset of dispersion [589]. A statistic analysis showed that the principal factors involved are the oil composition, dispersant formulation, sea surface turbulence, and dispersant quantity [588]. The composition of the oil is very important. The effectiveness of the dispersant formulation correlates strongly with the amount of the saturate components in the oil. The other components of the oil (i.e., asphaltenes, resins, or polar substances and aromatic fractions) show a negative correlation with the dispersant effectiveness. The viscosity of the oil is determined by the composition of the oil. Therefore viscosity and composition are responsible for the effectiveness of a dispersant. The dispersant composition is significant and interacts with the oil composition. Sea turbulence strongly affects dispersant effectiveness. The effectiveness rises with increasing turbulence to a maximal value. The effectiveness for commercial dispersants is a Gaussian distribution around a certain salinity value. 

In sufficiently dilute aqueous solutions surfactants are present as monomeric particles or ions. Above critical micellization concentration CMC, monomers are in equilibrium with micelles. In this chapter the term micelle is used to denote spherical aggregates, each containing a few dozens of monomeric units, whose structure is illustrated in Fig. 4.64. The CMC of common surfactants are on the order of 10 " -10 mol dm . The CMC is not sharply defined and different methods (e.g. breakpoints in the curves expressing the conductivity, surface tension, viscosity and turbidity of surfactant solutions as the function of concentration) lead to somewhat different values. Moreover, CMC depends on the experimental conditions (temperature, presence of other solutes), thus the CMC relevant for the expierimental system of interest is not necessarily readily available from the literature. For example, the CMC is depressed in the presence of inert electrolytes and in the presence of apolar solutes, and it increases when the temperature increases. These shifts in the CMC reflect the effect of cosolutes on the activity of monomer species in surfactant solution, and consequently the factors affecting the CMC (e.g. salinity) affect also the surfactant adsorption. 

A publication that specifically focuses on the screening criteria for chemical processes has not been seen in the literature. Screening criteria for broader EOR processes have been discussed by several researchers—for example, Taber et al. (1997a, 1997b), Al-Bahar et al. (2004), and Dickson et al. (2010). This section briefly summarizes several critical parameters regarding chemical EOR application conditions. Many parameters could affect chemical EOR processes however, the most critical parameters should be reservoir temperature, formation salinity and divalent contents, clay contents, and oil viscosity. Eor polymer flooding, permeability is another critical parameter. 

Salinity is essential for all chemical processes. It directly affects polymer viscosity, and it determines the type of microemulsion a surfactant can form. Salinity effects in waterflooding, in both sandstone and carbonate reservoirs, have recently drawn research interest. This chapter briefly discusses sahnity and ion exchange. At the end of this chapter, the sahnity effects on waterflooding in sandstone and carbonate reservoirs are summarized. 

Both the salinity and pol5nner concentration affect the volumetric ratios of separated phases and the fractionation of sulfonate and polymer in these phases. A proper selection of polymer concentration and salinity in a polymer-sulfonate mixture can result in equal viscosities of the separated phases (Szabo, 1979). This approach may not be practical, however, because a constant salinity or concentration cannot be maintained along the flow path because of adsorption and mixing, and so on. Therefore, we should try to select a formula that will not have an SPI problem. 

SAM has been more widely exploited with detection techniques involving nebulisation (e.g., FAAS, ICP-OES and ICP-MS), as this step tends to be particularly affected by sample matrix effects, mainly salinity and viscosity. Relevant examples of SAM exploitation with spectrophotometry are given below. 

Figure la shows the permeabihty distribution. It can be noted, that for calculation of distribution of the main parameters used heterogeneous field. In opposite corners of the selected area are two wells injection and production. These wells are set bottom hole pressure Pinj or Pprod)- Figure lb shows the results of calculating the distribution of pressure in domain. Distribution of water saturation, polymer and surfactant concentrations, which are pumped through injection well, presented in Figures 2, 3 and 4. It is considered that the salinity of injection water is equal to zero (Figure 5). In these calculations, the solution is pumped into the reservoir over the reservoir temperature, the distribution of which is shown in Figure 6. Thus, the problem is solved numerically in a simple formulation, i.e. not taken into accoimt changes in viscosity of the concentration of the reagents and temperature, polymer adsorption was not affected by the...

Beside concentration, the salinity of water used to prepare a polymer solution also has a major impact on apparent viscosity. A change in the quantity of water directly affects the polymer solution s viscosity. As mentioned above, when a polymer, like HP AM, is exposed to different salinity water, its anionic and cationic in the water would have attraction/ repulsion to the polymer chain, and make it compressed or stretched. When it exhibits to the distilled or low salinity water, the electrostatic repulsion between anionic groups along the polymer chains would be unshielded, make the polymer molecules... 

Compared with solutions of partially hydrolyzed polyacrylamides, viscosities of xanthan solutions are much less affected by changes in salinity or divalent-ion content. Figs. 5.17 and 5.1836 illustrate this by plotting the solution viscosity at various shear rates vs. salinity and divalent-ion content. 

The same phenomenon is observed in complexes that have been compacted under the shape of circular matrices. In fact, it can be seen in Fig. 18 that water sorption rate is proportional to the viscosities reported in Table 3. Thus, the high swelling capacity exhibited by the complexes of atenolol and hdocaine in salt free medium makes them highly susceptible to the saline effect. Thus, the sorption rate decreases when a NaCl solution is used instead of water. On the other hand, the complex with metoclopramide has a very low rate of water sorption reveal a limited swelling capacity whose rate is barely affected in NaCl solution. 

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