Double-Network Structure Slickwater Reinforced by Silane-Modified Nanofibers: Enhancing the Sand-Carrying Performance

Area of Science:

• Petroleum Engineering
• Materials Science
• Chemical Engineering

Background:

• Slickwater fracturing fluid is widely used in hydraulic fracturing for its low friction and minimal formation damage.
• A key limitation of slickwater fluid is its poor sand-carrying performance due to low viscosity, impacting fracturing efficiency.
• There is a critical need for advanced slickwater systems with superior proppant-carrying capabilities.

Purpose of the Study:

• To develop a novel slickwater fracturing fluid with enhanced sand-carrying performance.
• To investigate the efficacy of silane-modified cellulose nanofibrils (S-CNFs) in improving slickwater rheology and proppant transport.

Main Methods:

• Silane modification of cellulose nanofibrils (CNFs) to create S-CNFs, confirmed by FT-IR and XPS.
• Incorporation of S-CNFs into conventional slickwater to create a reinforced fluid.
• Evaluation of fluid properties through rheological tests, viscoelasticity tests, dynamic proppant-carrying experiments, and SEM imaging.

Main Results:

• S-CNFs demonstrated excellent dispersion stability and improved the rheological properties of slickwater, including strength and temperature shear resistance.
• The S-CNFs-reinforced slickwater exhibited a wider elasticity-dominated range, indicating enhanced proppant-carrying capacity.
• Dynamic experiments showed reduced sand bank area (16.4%) and residual sand (14.8%) compared to conventional slickwater, with deeper proppant transport.
• SEM analysis revealed a double-network structure formed by polymers and S-CNFs, explaining the improved performance.

Conclusions:

• Silane-modified cellulose nanofibrils (S-CNFs) significantly enhance the rheological properties and sand-carrying capacity of slickwater fracturing fluids.
• The developed S-CNFs-reinforced slickwater offers a viable solution for improving the effectiveness of hydraulic fracturing operations.
• This study provides a theoretical basis for developing advanced nanofiber-based fracturing fluids.