ASPHALTENE CONTENT IN HEAVY OIL Russian patent published in 2018 - IPC E21B47/00 E21B49/08 

FIELD: oil and gas industry.

SUBSTANCE: method comprises: moving a downhole tool in a wellbore passing through the ground formation, wherein the ground formation comprises a fluid of different viscosities; extracting the fluid into the downhole tool and measuring fluorescence intensity; estimating the content of asphaltenes in the extracted fluid based on the measured fluorescence intensity, wherein the ratio of fluorescence intensity to asphaltenes is not linear and is determined, for example, by the following formula: , where I_ƒ is the measured fluorescence intensity; α is a fitting parameter; β' is a parameter defined as (8RTτ₀)/3; R is a universal gas constant; T is the temperature of the extracted fluid; τ₀ is the fluorescence lifetime; η is the viscosity; [A] is the content of asphaltenes.

EFFECT: increased accuracy of the determination of asphaltene content in the oil formation.

19 cl, 6 dwg