This work focuses on controlling the filtration characteristics of water-based drilling muds (WBDMs) under high temperature (HT) and high salinity (HS), which are fundamental for safety and resilience during deep-well drilling operations. It leveraged on the synergistic benefits of thermo-responsive behavior, the anti-polyelectrolyte effect, and biogenic nanosilica (bSiNP) extracted from rice husk to develop thermo-responsive Janus biogenic silica nanocomposites (TRJA). Results indicated that, among the nanomaterials, TRJA-2, with a Janus ratio of 1:1 (based on polymeric face/amino group face), exhibited the strongest anti-polyelectrolyte effect, contributing to the significant colloidal stability in brine, especially above 2.5 up to 36 wt% NaCl (ca. saturated environment) compared to bSiNP, aminated-bSiNP, symmetrical counterpart (TRA), and those with a distinctive Janus ratio. As a result, TRJA-2 yielded an 11.25-fold filtrate loss control against bSiNP and better than its counterparts in NaCl-saturated mud at 210 °C. The steady shear viscosity and consistency plots further revealed that TRJA-2 fortified NaCl-saturated mud demonstrated the highest steady shear viscosity compared to its counterparts at 210 °C, particularly in the zero-shear rate region. Thus, the highest relaxation time and ultimately the lowest critical shear thinning rate should be expected based on the Carreau-Yasuda model. Microscopically, the inward active amino face of TRJA-2 strongly interacted with bentonite platelets via electrostatic attractive force, triggering an alteration of the functional groups under a NaCl-saturated environment. This contributed to increasing affinity between the TRJA-2 and bentonite particles at HT, favouring the creation of a tight hydrophobic layer over the surface of the mud cake from the outward face. This was beneficial not only for the formation of an appropriate particle size distribution but also for a firmed, homogenized, and compacted mud cake. This research proposes a novel approach to sustain a low filtrate volume of WBDMs using agricultural waste-based products under HT and HS. • A series of Janus nanocomposites, TRJA, with a biogenic nanosilica core derived from rice husk, are successfully synthesized. • The colloidal stability of TRJAs is assessed with respect to electrolyte strength. • TRJA-2 greatly enhances the filtration loss control of saturated-NaCl drilling mud at 210 °C. • The filtration loss control mechanism is explored.
Tchameni et al. (Tue,) studied this question.