Peculiarities of applying the technology for oil displacement by polymer solutions in stratified inhomogeneous bed of White Tiger field

UDK: 622.276.6

DOI: DOI: 10.24887/0028-2448-2017-3-90-93

Key words: polymer flooding, stratified inhomogenous bed, fluids cross-flow, polymer layer, reservoir model, radioactively irradiated polymer, watersoluble compositions, mud pumping

Authors: Tu Thanh Nghia, M.M. Veliev, Tran Quoc Khoi, A.N. Ivanov (Vietsovpetro JV, the Socialist Republic of Vietnam, Vung Tau)

Analysis of the status of the Lower Miocene development indicates the nonuniform oil reserves recovery in various areas of the reservoir. The oil recovery factor remains low, while the water-cut of the produced products increases. By means of increasing the displacing factor and areal sweep efficiency, the reservoir flooding technology based on polymer solutions allows significantly improve the production and economic performance of fields. The basis for the most implemented soluble polymers is polyacrylamide, which has limits in temperature (no higher than 90^oC) and salinity (for mediums with low salinity). The indicated properties prevent the polyacrylamide-based polymer solutions from wide implementation in oil-field practices under conditions of Vietsovpetro JV.

To improve the oil-displacing factor during Lower Miocene flooding at White Tiger field the radio irradiated polymer systems and methods for their rheological and physical properties control were developed. Using of radioactive irradiation new polymer was synthesized. Its viscosity is much higher than the viscosity of the initial polymer.

Study of the temperature influence on the new polymer solution viscosity under various concentrations revealed that the polymer system viscosity has a tendency to decrease under temperature rise. In that way, the viscosity lowers 2 times under low concentration and reduces 4 times under high concentration with temperature variation from 30 to 90^oC.

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