11/30/2023 0 Comments Water in oil emulsion volum fraction![]() Moreover, for a given water fraction, the reduction in drag of stable water-in-oil emulsions was found to be more pronounced in smaller pipe diameter due to the shear thinning effect and became significant at higher values of water fraction and Re. In one case, a decrease of water volume fraction from 0.7 to 0.6 resulted in a 60 to 75% drag reduction, depending on the Reynolds number (Re). Furthermore, a significant reduction in emulsion viscosity and pressure drop with decreasing water fraction was observed. In addition, as water fraction increased emulsion stability increased. The results demonstrated a shear thinning behavior for the emulsions being investigated. Emulsion physical properties such as stability, type, and rheology measurements were correlated to pressure drop measurements in a flow loop consisting of 1-in and 0.5-in horizontal pipe diameters at constant (ambient) emulsion temperature. This study experimentally investigates the role of dispersed phase (water) fraction on frictional drag in different pipe diameters.įlow loop experiments were conducted to study the effect of water fraction on the flow characteristics of surfactant-stabilized water-in-oil emulsions. the signal decreases again when the oil concentration further increases.High friction losses while pumping emulsified acid in a carbonate stimulation treatment limit the injection rate, which can negatively impact operational efficiency consequently, reducing friction is highly desirable. An increase of the oil concentration first also means an increase of the receiver signal, but here multiple scattering also leads to a reversal of the effect, i.e. This light that is generated by fluorescence is emitted in all directions, and some of this light also arrives at the receiver optics. In case of an O/W emulsion the UV light that is emitted by the sensor impinges on the oil droplets (inner phase), and in case of a W/O emulsion on the outer phase (dispersion medium), and is converted into the visible range by the oil molecules (fluorescence). With this method a sensor is used that contains both the UV transmitter unit and the receiver unit for visible light. This method is suitable for low to medium particle concentrations.ĭetermining the oil fraction of an O/W or W/O emulsionĮmulsions on mineral-oil or vegetable-oil basis can be excited to fluoresce by using UV light. An increase of the droplet concentration results in a signal increase at the sensor. Similar to the lateral scattering method the scattered light that is generated by the droplets is used to determine the phase-volume ratio. When the droplet concentration becomes too high, however, the effect may reverse due to multiple scattering. With low to medium concentrations there primarily is single scattering. An increase of the phase-volume ratio first leads to a signal increase at the receiver unit. The receiver unit is arranged at an angle of 90° with respect to the optical axis of the transmitter unit's light beam. The droplets also generate scattered light in this method. When the number of droplets increases (higher phase-volume ratio) the light quantity that is measured by the receiver unit decreases. The light that is emitted by the transmitter unit is partially diffusely reflected (light scattering) or absorbed by the droplets of the emulsion. Relaxation frequencies varying from 110 MHz for a volume fraction of 11 water in oil to about 210 MHz for a volume fraction of 1.5 water in oil are. Various methods can be used for this measurement: ![]() Based on the assumption that the average particle diameter of the droplets of the inner phase during a change of the phase-volume ratio corresponds with, turbidity measurement can provide information about the phase-volume ratio. The phase-volume ratio is the quotient of the volume fraction of the inner phase and the volume fraction of the outer phase. ![]()
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