TY - THES

T1 - Performance Evaluation of Polymer Solutions in Enhanced Oil Recovery

T2 - A Study on Liquid and Powder Polymer Flooding

AU - Ghodsi, Elham

N1 - no embargo

PY - 2024

Y1 - 2024

N2 - This study investigates the feasibility of liquid polymer flooding in Austrian oil reservoirs, focusing on the Hochleiten field with permeabilities ranging from 300 to 500 mD and extending to higher permeability (1300 mD) to assess the broader applicability of liquid polymers. The research compares the performance of liquid and powder polymers from two vendors, evaluating their potential as alternatives for EOR in challenging reservoir conditions. Four liquid polymer products (LP#1-4) and four powder polymer products (PP#1-4) with varying molecular weights were systematically tested. The target polymer concentration was set to achieve 20 cP viscosity at 20°C. Comprehensive experiments included stability tests, Interfacial Tension (IFT) measurements, phase behavior analyses, and core flooding tests at an interstitial velocity of 5 ft/day. Initial stability, IFT, and phase behavior tests showed promising results for liquid polymers. However, subsequent single-phase and two-phase core flooding experiments revealed significant injectivity challenges for liquid polymers across low permeable rocks. These challenges manifested as continuous pressure increases without stabilization, contrasting with the stable pressure profiles observed with powder polymers. In two-phase core floods, LP#4's concentration was reduced from 1800 ppm to 900 ppm to investigate whether a less viscous solution could resolve the observed injectivity issues. Despite this adjustment, injectivity problems persisted. For PP#3, the concentration was increased from 1400 ppm to 2000 ppm in two-phase core floods to examine the impact of a more viscous polymer solution on the recovery factor and differential pressure across the core plug. Adsorption tests showed comparable results for both liquid and powder polymers, with measurements around 250 μg/g of rock. Resistance and residual resistance factors were successfully determined for powder polymers but could not be accurately assessed for liquid polymers due to their unstable pressure profiles. The study concludes that while liquid polymers show potential in certain aspects, they face substantial injectivity challenges in the permeability range typical of the Hochleiten field. In contrast, powder polymers, particularly PP#4, demonstrated superior performance and stability across all tested permeabilities, making them more suitable candidates for EOR applications in these reservoirs. These findings provide critical insights for optimizing EOR strategies in mature Austrian oil fields and contribute to the broader understanding of polymer behavior in complex reservoir conditions across a range of permeabilities.

AB - This study investigates the feasibility of liquid polymer flooding in Austrian oil reservoirs, focusing on the Hochleiten field with permeabilities ranging from 300 to 500 mD and extending to higher permeability (1300 mD) to assess the broader applicability of liquid polymers. The research compares the performance of liquid and powder polymers from two vendors, evaluating their potential as alternatives for EOR in challenging reservoir conditions. Four liquid polymer products (LP#1-4) and four powder polymer products (PP#1-4) with varying molecular weights were systematically tested. The target polymer concentration was set to achieve 20 cP viscosity at 20°C. Comprehensive experiments included stability tests, Interfacial Tension (IFT) measurements, phase behavior analyses, and core flooding tests at an interstitial velocity of 5 ft/day. Initial stability, IFT, and phase behavior tests showed promising results for liquid polymers. However, subsequent single-phase and two-phase core flooding experiments revealed significant injectivity challenges for liquid polymers across low permeable rocks. These challenges manifested as continuous pressure increases without stabilization, contrasting with the stable pressure profiles observed with powder polymers. In two-phase core floods, LP#4's concentration was reduced from 1800 ppm to 900 ppm to investigate whether a less viscous solution could resolve the observed injectivity issues. Despite this adjustment, injectivity problems persisted. For PP#3, the concentration was increased from 1400 ppm to 2000 ppm in two-phase core floods to examine the impact of a more viscous polymer solution on the recovery factor and differential pressure across the core plug. Adsorption tests showed comparable results for both liquid and powder polymers, with measurements around 250 μg/g of rock. Resistance and residual resistance factors were successfully determined for powder polymers but could not be accurately assessed for liquid polymers due to their unstable pressure profiles. The study concludes that while liquid polymers show potential in certain aspects, they face substantial injectivity challenges in the permeability range typical of the Hochleiten field. In contrast, powder polymers, particularly PP#4, demonstrated superior performance and stability across all tested permeabilities, making them more suitable candidates for EOR applications in these reservoirs. These findings provide critical insights for optimizing EOR strategies in mature Austrian oil fields and contribute to the broader understanding of polymer behavior in complex reservoir conditions across a range of permeabilities.

KW - Enhanced Oil Recovery

KW - Liquid polymer flooding

KW - Powder polymers

KW - Austrian oil reservoirs

KW - Hochleiten field

KW - Injectivity challenges

KW - Core flooding experiments

KW - Polymer stability

KW - Interfacial Tension

KW - Adsorption tests

KW - Resistance factors

KW - Polymer concentration optimization

KW - one-phase core floods

KW - Two-phase core floods

KW - Enhanced Oil Recovery

KW - Pulverpolymerflutung

KW - Österreichische Erdöllagerstätten

KW - Hochleiten-Feld

KW - Injektivitätsherausforderungen

KW - Kernflutungsexperimente

KW - Polymerstabilität

KW - Grenzflächenspannung

KW - Adsorptionstests

KW - Widerstandsfaktoren

KW - Polymerkonzentrationsoptimierung

KW - Einphasige Kernflutungen

KW - Zweiphasige Kernflutungen

U2 - 10.34901/mul.pub.2025.005

DO - 10.34901/mul.pub.2025.005

M3 - Master's Thesis

ER -