Minimum CO₂ Miscibility Pressure Evaluation using Interfacial Tension (IFT) and Slim-tube Hybrid Tests

Area of Science:

• Petroleum Engineering
• Chemical Engineering
• Geoscience

Background:

• The efficiency of CO2-enhanced oil recovery (EOR) is critically linked to the CO2-oil minimum miscible pressure (MMP).
• Accurate MMP determination is essential for optimizing EOR operations and maximizing hydrocarbon recovery.
• Various experimental and simulation techniques exist for estimating MMP, each with its own advantages and limitations.

Purpose of the Study:

• To evaluate and compare different methods for estimating the CO2-oil MMP.
• To assess the accuracy and efficiency of interfacial tension (IFT) and slim-tube tests in MMP determination.
• To compare experimental MMP data with equation of state (EOS) simulations for EOR applications.

Main Methods:

• Interfacial tension (IFT) measurements were conducted to determine MMP.
• Slim-tube tests were performed to evaluate MMP under dynamic displacement conditions.
• MMP values were compared between IFT, slim-tube tests, visual observation, and EOS simulations.

Main Results:

• IFT tests yielded slightly higher MMP values compared to slim-tube tests, with differences of 0.7% and 4.3% at 60 and 66 °C, respectively.
• EOS simulations provided MMP estimates that were higher than experimental methods but within a close range.
• Consistent deviations between slim-tube tests and EOS simulations were observed across different temperatures.

Conclusions:

• Both IFT and slim-tube tests are viable methods for estimating CO2-oil MMP in EOR.
• EOS simulations offer a complementary approach, providing comparable results to experimental techniques.
• This study provides a validated framework for accurate and efficient MMP evaluation for CO2-EOR projects.