Evaluation and Experiment of High-Strength Temperature- and Salt-Resistant Gel System

Area of Science:

• Petroleum Engineering
• Polymer Science
• Materials Science

Background:

• Conventional gel systems face challenges with thermal stability, salt tolerance, and environmental risks in harsh reservoir conditions.
• Developing effective profile control agents is crucial for enhancing oil recovery in high-temperature, high-salinity heterogeneous reservoirs.

Purpose of the Study:

• To develop a novel triple-synergy gel system with enhanced thermal stability and salt tolerance.
• To optimize the gel system's composition and synthesis parameters for challenging reservoir environments.
• To evaluate the gel system's performance in improving crude oil utilization and selective plugging.

Main Methods:

• Response surface methodology was employed to determine optimal synthesis parameters for the APAM, PEI, and SMP gel system.
• A time-viscosity model was established to characterize the gel's behavior.
• Nuclear magnetic resonance (NMR) displacement tests and parallel dual-core flooding experiments were conducted to assess performance.

Main Results:

• The optimized gel system demonstrated excellent thermal stability (93.48% mass retention at 110 °C) and structural integrity under high salinity (150,000 ppm).
• The gel system exhibited a uniform porous structure (2-8 μm) and significantly improved crude oil utilization efficiency in micropores (21.32%).
• Selective plugging in heterogeneous systems (10:1 permeability contrast) was confirmed, with a 98.7% plugging rate in high-permeability layers and a 13.6% increase in low-permeability layer recovery.

Conclusions:

• The developed triple-synergy gel system offers a green and efficient profile control solution for deep, high-temperature, high-salinity reservoirs.
• This innovative gel system overcomes the limitations of conventional gels, providing superior performance in extreme conditions.
• The study highlights the potential of synergistic gel formulations for advanced oil recovery applications.