Mutual displacement of liquids in oil deposits
UDC: 622.276.031:531.5
DOI: 10.33285/0207-2351-2022-5(641)-25-31
Authors:
LIVINTSEV PETR N.
1,
VERZHBITSKY VYACHESLAV V.1,
GUNKINA TATIANA A.1,
HANDZEL ALEXANDER V.1,
VERZHBITSKAYA VICTORIA V.1
1 North-Caucasus Federal University, Stavropol, Russia
Keywords: relative phase permeabilities, horizontal and vertical filtration of mixtures of water with oil, long-term water cut oil production, velocities of oil floating up and water sinking during segregation of their mixtures in reservoirs
Annotation:
When developing fields, oil is usually displaced towards the wells by invading edge water. The features of joint (two-phase) filtration of the resulting water and oil mixtures and their segregation require further studying.
The article discusses the filtration of mixtures of liquids in cases requiring no consideration of capillary forces or when they are indirectly accounted for using three types of relative permeability curves.
Analytical methods are used to study the features of horizontal and vertical filtration of water and oil mixtures and the segregation of these fluids. For three models of the relative phase permeability dependences on water saturation, analogs of the Buckley – Leverett function as well as analytical formulas for the velocities of filtration and liquids’ vertical movement in layers were obtained. Formulas for the velocity of water sinking down and of oil floating-up during segregation are obtained. Filtration of liquids mixtures and their mutual displacement are studied with the help of analytical mathematical methods.
In case of horizontal and vertical filtration of oil and water mixtures, the same volume of mixtures passes through the reservoir sections perpendicular to the flow; the volumes of oil and water mutually displace each other in the case of a constant flow rate of the mixture.
Simple formulas for calculations of horizontal and vertical filtration of liquid mixtures and their mutual displacement are obtained. Explanatory graphs and calculation results are presented.
Oil floating up from the oil-water mixture accumulates during segregation and moves near the roof of the formation. This phenomenon contributes to the long-term production of the water-cut oil.
The velocities of oil floating up and water sinking during segregation are proportional to the segregation coefficient, which itself is proportional to the value of the absolute vertical permeability of the reservoir.
The formulas found in the course of the study and calculations based on them showed the possibility of relatively rapid oil floating up and water down sinking in the layers of deposits with increasing water cut. These phenomena cause long-term production of the water-cut oil during pumping of edge water into the reservoirs.
Bibliography:
1. Pykhachev G.B., Isaev R.G. Podzemnaya gidravlika. – M.: Nedra, 1973. – 360 s.
2. Podzemnaya gidromekhanika / K.S. Basniev, N.M. Dmitriev, R.D. Kanevskaya, V.M. Maksimov. – M.: Nedra, 2006. – 488 s.
3. Podzemnoe khranenie gaza: ucheb. posobie / M.V. Lur'e, A.S. Didkovskaya, D.V. Varchev, N.V. Yakovleva. – M.: Neft' i gaz, 2004. – 172 s.
4. Alishaev M.G. Modelirovanie i raschet v prikladnoy matematike i dobyche nefti. – Makhachkala: ALEF, 2015. – 288 s.
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