Intercalated Montmorillonite Nanocomposites for Sustainable Flow Assurance of Indian Waxy Crude Oil in Low-Temperature Environments

Flow assurance challenges associated with wax precipitation and subsequent crystallization in crude oil transportation lines require efficient and sustainable flow improvers. In this work, three montmorillonite (MMT) nanoclay-based composites, designated as MCP, MCE, and MCPE, were synthesized via hot solvent blending of CTAB-intercalated MMT nanosheets into poly(methyl methacrylate) polymer (PMMA) and ethylene-vinyl acetate (EVA) copolymer matrices. Their performance as flow improvers was systematically evaluated using two Indian waxy crude oils with varying wax contents. The prepared nanohybrids were characterized by X-ray diffraction (XRD) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), and field emission transmission electron microscopy (FETEM). Viscosity measurements revealed significantly improved low-temperature flow behavior for both crude oils, with superior viscosity reduction of up to ∼87.5% at temperatures as low as 15 °C. Yield stress measurements at 10 °C revealed a significant reduction of up to 898 Pa. Additionally, a maximum pour-point depression of 10 °C was achieved at a dosage of 200 ppm. DSC analysis indicated a reduction in the wax appearance temperature of up to 2.4 °C. Polarized optical microscopy analysis further revealed the morphological changes in the wax crystals, promoting effective wax inhibition as well as reducing the mean crystal size. Overall, the results obtained in this study demonstrated that all the synthesized nanocomposites can be applied as effective flow improvers for waxy crude oils. A beneficiation mechanism based on the synergistic effect of nanoclay-promoted heterogeneous nucleation and adjacent polymer chain-facilitated radial cocrystallization is proposed.