Optimization of determination of level of aggrigating of asphalten in crude oil

Depending on content of asphalten compounds in the crude oil the color of the latter changes beginning from the black as far as light yellow. For example, the Baku crude oil is featured by blue illumination and Grozny one by green light. The more content of asphalten in the crude oil the darker is latter. According tothe experimental researches the level of aggregation effects on spectral characteristics of crude oil. It is suggested that the variation of concentration of asphalten leads to changingof its agrigation condition which inevitably changes the spectral characteristics of crude oil. It is shown that the existed methodics for assessment of aggregation condition of crude oil doesn’t contain the quantitative parameters for determination of accuracy of assessment depending of selected wave length of measurements. The new methodicsfor optimum assessment of accuracy of determination of aggregation condition of asphalten is suggested.
Materials and methods
In order to determine the level of aggregation of asphalten using n-pentane as a solvent itis taken into account that in some zones of wave lengths the optical density of n-pentane increases and in some others decreases. The total error is determined as a weighted sum of error of measuring of polystyrene particles depending on radius of partyicles and error of measurements of asphalten dissolved in n-pentane. The research task is selection of such optimum zones of wavelengths for above measurements where the errors of appropriate measurements changes in anti-phase order depending on wavelength and compensate each other.
Results
Thus it is shown that for optimization of process of studying of condition of aggregation of asphalten within crude oil the followingtwo components of total error should be considered:
1. The component of error of determination of optical depth of asphaltens particles occurred due to divergence of predicted value of optical depth at given wavelength.
2. The component of equivalent error occurred due to change of optical depth of n-pentane upon change of wavelength.
Сonclusions
It is shown that upon some conditions when the wavelength is changing the anti-phase variation of total error components is observed. Considering these components as a partial criteria of optimization the task of multi-criteria optimization was formed and solved linked with search of minimum of weighted linear convolution composed of said components.