A review of cellulose nanomaterial-stabilized Pickering foam: Formation, properties, and emerging oilfield applications

The rapid development of the petroleum industry has led to increasing demands for high-performance oilfield working fluids, such as drilling fluids, fracturing fluids, and fluids for enhanced oil recovery. Liquid foam is widely utilized as the oilfield working fluids due to its advantages, including low density, high mobility, superior cutting suspending ability, excellent fluid diversion capacity, and outstanding sweep efficiency. However, the short lifespan of foam limits its broad application in the oilfield. Considering the advantages of environmental protection, renewability, high specific surface area, tailorable surface chemistry, and excellent rheological properties of cellulose nanomaterials (CNMs), Pickering foams stabilized by CNMs offer improved eco-friendliness and foam stability. In this review, the classification and preparation methods of CNMs are briefly introduced. Subsequently, the preparation methods, properties, and application prospects of CNM-stabilized Pickering foams as oilfield working fluids are summarized. Finally, the challenges and prospects of CNM-stabilized Pickering foam are outlined, aiming to pave the way for the development of petroleum industry in an eco-friendlier manner.