Lignin-containing cellulose nanofibers as stabilizers in Pickering emulsion-based drilling fluids

Area of Science:

• Materials Science
• Environmental Science
• Petroleum Engineering

Background:

• Conventional drilling fluids pose environmental risks due to mineral oils and surfactants.
• Limited research exists on sustainable alternatives for drilling fluid formulations.

Purpose of the Study:

• To develop a sustainable Pickering emulsion drilling fluid system.
• To utilize mechanically treated lignin-containing cellulose nanofibers (MLCNFs) as stabilizers and biodiesel as the base oil.
• To evaluate the performance and environmental compatibility of the developed drilling fluid.

Main Methods:

• Characterization of MLCNFs' physicochemical properties.
• Elucidation of emulsion stabilization mechanisms using SEM and CLSM.
• Performance evaluation including emulsion stability, rheology, filtration, and ecotoxicity.

Main Results:

• The MLCNF-stabilized Pickering emulsion drilling fluid demonstrated enhanced emulsion stability (78 mV), viscosity, yield point, and reduced fluid loss (4.5 mL FLAPI).
• Superior environmental compatibility was observed with EC50 of 9.48 × 10^4 mg/L and BOD5/CODcr of 42.7%.
• Synergistic stabilization by lignin nanoparticles and cellulose nanofibers within MLCNFs formed a robust interfacial film and 3D network.

Conclusions:

• The developed MLCNF-stabilized Pickering emulsion drilling fluid is a high-performance, environmentally friendly alternative to conventional options.
• The cooperative stabilization mechanism involving MLCNFs and bentonite contributes to superior rheological and filtration properties.
• This research offers a sustainable solution for the drilling industry, addressing environmental concerns associated with traditional drilling fluids.