Research of polymer solutions and surfactant-polymer compositions for enhanced oil recovery

UDK: 622.276.61

DOI: 10.24887/0028-2448-2026-7-42-45

Key words: : chemical flooding, polyacrylamide, surfactant, oil displacement properties, incremental oil recovery factor

Authors: M.R. Khisametdinov (TatNIPIneft, RF, Almetyevsk); G.R. Karimova (TatNIPIneft, RF, Almetyevsk); E.I. Varlamova (TatNIPIneft, RF, Almetyevsk); A.I. Kashapov (TatNIPIneft, RF, Almetyevsk); A.T. Zaripov (TatNIPIneft, RF, Almetyevsk); K.A. Trots (TATNEFT Research and Development Centre, RF, Almetyevsk)

The paper presents key findings of coreflood experiments aimed to determine oil displacement performance of polymer solutions depending on concentration of two types of polyacrylamide (PAA) (medium- and high molecular) in presence of surfactants. Coreflooding is the most insightful method for research of mixed oil displacement compositions, enabling performance comparison at different concentrations and various physical and chemical properties, to determine the most important properties of compositions and select efficient solutions for specific conditions. The experiments were conducted under conditions typical of terrigenous Devonian and Bobrikovian sediments with permeability of core samples ranging from 0,303 to 0,726 μm2, and oil viscosity of 17,2–21,3 mPa·s for the terrigenous Devonian and 41,6–54,5 mPa·s for the Bobrikovian. The key polymer property that influences the oil displacement is viscoelasticity, which depends on concentration and molecular weight of the polymer, temperature, water salinity, permeability, and other conditions. Coreflood experiments revealed that under given experimental conditions PAA resistance to high salinity and PAA molecular weight have the largest impact on oil displacement properties of PAA solutions and surfactant-polymer compositions (with the same amount of surfactants in the composition), moreover surfactant-polymer composition ensures manyfold increase in displacement efficiency compared to PAA solution. Maximum increase in oil displacement efficiency for surfactant-polymer compositions studied under conditions typical of terrigenous Devonian and Bobrikov sediments was 29,8 % and 30,6 % respectively.

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