TY - THES

T1 - Statistical Analysis of the Microscopic Fluid Phase Distribution in Microfluidics for EOR Screening

AU - Schnöpf, Barbara

N1 - no embargo

PY - 2019

Y1 - 2019

N2 - Alkaline flooding, as one of the chemical EOR processes, modifies the properties of fluid-fluid as well as rock-fluid interfaces in the reservoir in order to mobilize additional oil. In this thesis, observations on the pore scale were recorded and analysed to provide information on the displacement mechanism of brine and alkaline flooding which was applied to crude oil. The alkaline concentration ranged from 200ppm to 12000ppm. Microfluidics were used to visualize the dynamic oil distribution in the pore space and the formation of emulsion phases. In means of the statistical analysis, the Lorenz plot and normalized Euler characteristic were applied. Phase behaviour experiments provided additional information about the different phases and formation of emulsions. The experiments were carried out at ambient temperature conditions as well as reservoir temperature conditions to attain a more realistic approach. For some cases, a spinning drop measurement additionally provided data on interfacial tension. The highest ultimate recovery was achieved at ambient temperature conditions in the flooding scenario of synthetic brine with 12000ppm alkaline salt, which resulted in an oil-wet system. An entirely water-wet system was only achieved by using deionized water in combination with alkaline salt. Temperature flooding experiments were carried out with brine and deionized water, each in solution with 3000ppm alkaline salt, since this was initially assumed to be an ideal concentration due to promising results with another oil in the same field. The phase behaviour experiment of synthetic water with 5000ppm alkaline salt showed an optimum at reservoir temperature conditions. There was no comparable behaviour found at ambient temperature conditions which emphasizes the great effect that temperature has on mixing conditions.

AB - Alkaline flooding, as one of the chemical EOR processes, modifies the properties of fluid-fluid as well as rock-fluid interfaces in the reservoir in order to mobilize additional oil. In this thesis, observations on the pore scale were recorded and analysed to provide information on the displacement mechanism of brine and alkaline flooding which was applied to crude oil. The alkaline concentration ranged from 200ppm to 12000ppm. Microfluidics were used to visualize the dynamic oil distribution in the pore space and the formation of emulsion phases. In means of the statistical analysis, the Lorenz plot and normalized Euler characteristic were applied. Phase behaviour experiments provided additional information about the different phases and formation of emulsions. The experiments were carried out at ambient temperature conditions as well as reservoir temperature conditions to attain a more realistic approach. For some cases, a spinning drop measurement additionally provided data on interfacial tension. The highest ultimate recovery was achieved at ambient temperature conditions in the flooding scenario of synthetic brine with 12000ppm alkaline salt, which resulted in an oil-wet system. An entirely water-wet system was only achieved by using deionized water in combination with alkaline salt. Temperature flooding experiments were carried out with brine and deionized water, each in solution with 3000ppm alkaline salt, since this was initially assumed to be an ideal concentration due to promising results with another oil in the same field. The phase behaviour experiment of synthetic water with 5000ppm alkaline salt showed an optimum at reservoir temperature conditions. There was no comparable behaviour found at ambient temperature conditions which emphasizes the great effect that temperature has on mixing conditions.

KW - EOR

KW - Alkaline Flooding

KW - Microfluidics

KW - EOR

KW - Alkaline Flooding

KW - Microfluidics

M3 - Master's Thesis

ER -