Study on the Enhancement of Recovery Rates in Heterogeneous Dense Reservoirs Using Foam Drives Stabilized by...

Area of Science:

• Petroleum Engineering
• Enhanced Oil Recovery
• Colloid and Surface Science

Background:

• Traditional water flooding is ineffective in low-permeability reservoirs due to issues like high salinity and heterogeneity.
• Improving oil recovery in challenging reservoirs requires advanced chemical flooding techniques.

Purpose of the Study:

• To develop and evaluate a low interfacial tension and salt-resistant nano-scale particle-stabilized foam flooding system (LITF-NSF) for low-permeability oil reservoirs.
• To determine the optimal injection parameters for the LITF-NSF system and assess its performance.

Main Methods:

• Core dynamic plugging and injectivity experiments.
• Single/dual-tube core displacement and static imbibition experiments.
• Evaluation of injectivity, plugging effect, imbibition effect, and oil displacement mechanism under varying injection pressures, slug volumes, and gas-liquid ratios.

Main Results:

• The LITF-NSF system demonstrated good injectivity with a resistance coefficient of 1.086–15.468.
• Optimal parameters identified: 5 MPa constant pressure difference, 0.3 PV slug volume, and 2:1 gas-liquid ratio.
• Achieved a 29.77% increase in subsequent water flooding recovery, over 10% increase in heterogeneous reservoirs, and 4.38% higher static imbibition recovery than pure water.

Conclusions:

• The LITF-NSF foam flooding system exhibits excellent adaptability and stable foam performance in target reservoir environments.
• This system effectively improves subsequent water flooding recovery rates.
• LITF-NSF shows significant application prospects for chemical flooding in low-permeability oil reservoirs.