105 / 2021-10-27 11:12:39

Lignocellulosic Nanofibers from Energy Cane Bagasse as fluid modifiers in Oil Drilling field

Cellulose Nanofibers; Lignin-containing Cellulose Nanofibers; Drilling Fluids; Fracturing Fluids; Rheology

Energy cane bagasse (ECB) is the major residue after the cane is milled to extract juice for sugar, biochemical, and/or biofuel production. The sustainable conversion of ECB into high value-added products can help reduce agricultural waste, and enhance utilization of bioresources. ECB can be converted into cellulose nanofibers (CNFs) that can serve as high value-added additives in bentonite water-based fluids (BT-WDFs). Particularly, CNFs were rapidly isolated from ECB by microwave-assisted NaOH / NaClO₂ and mechanical treatments (wet-grinding and microfluidization). CNFs suspensions exhibited typical shear-thinning behaviors and solid-like viscoelastic properties due to the entangled network structure of the CNFs. Formulated fluids with 0.5 wt% of the manufactured CNFs showed good rheological and fltration properties, demonstrating their potential applications in the oil service industry. Also, lignin-containing cellulose nanofibers (LCNFs) were produced from ECB using microwave assisted deep eutectic solvent (MV-DES) treatment in combination with ultrasonication, which can be used as rheology and filtration modifiers in BT-WDFs. The yield of lignocellulose is up to 45.2 % with 81.0 % delignification under the optimal reaction condition (110 ℃, 30 min). The resulting LCNF exhibited a highly entangled network, which was caused by the binder role of lignin between cellulose nanofibers. Compared with the CNFs suspension, the LCNFs suspension with the same concentration showed a higher viscosity and a more obvious entangled network structure due to the binder role of lignin between nanocelluloses. Therefore, the addition of a small amount of LCNFs (0.1 wt%) can greatly improve the rheological properties and filtration properties of low-solids WDFs, even better than high-solids WDFs, providing a novel WDF that is sustainable and green for drilling applications. In addition, the application of LCNFs in fracturing fluids (FFs) can also suspend proppants well (even at high temperatures after standing for 24 hours), which significantly improved the rheological properties and suspension stability of FFs. This also provides a sustainable and green approach to improve the oil and gas productivity in the fracturing process.