SELECTION AND CONTROL METHOD OF EFFICIENCY OF DEMULSIFIER AT OIL DEHYDRATION Russian patent published in 2012 - IPC C10G33/04 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to oil sampling, determination for them of relationship of tangent of an angle of dielectric losses and frequency tgδ(f), determination of resonance frequencies of oil and demulsifier (f_mo and f_md), which correspond to maximum values of tangent of the angle of dielectric losses of oil and demulsifier (tgδ_mo and tgδ_md), frequencies f_1d, f_2d from the following ratio: tgδ_d(f_1d, f_2d)=0.7 tgδ_md, where f_1d, f_2d - frequencies of electromagnetic field at which tgδ_d=0.7tgδ_md, selection of effective demulsifier for this oil, on the basis of frequency f_mo corresponding to maximum oil value tgδ_m from water concentration K in oil, which falls within the range f_1d÷f_2d, determination as per curve f_mo(K) of water quantity "Ф", after delamination of which f_mo will not be at the interval of f_1d÷f_2d; selection of demulsifier with other dielectric properties after water delamination in quantity "Ф". At that, oil, its water-oil emulsions and tested demulsifiers, before relationship of tangent of angle of dielectric losses and frequency tgδ(f) is determined for them, are heated to dehydration temperature T_dehyd 50-80°C, and determination of frequency relationships of tangent of angle of dielectric losses is performed at temperature T_dehyd.

EFFECT: improving the accuracy of method of selection of effective demulsifiers and control of efficiency which could consider the varying electric and physical properties of oil not only due to water content, but also thermal conditions of oil dehydration.

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