Rheological behavior of a bentonite mud

Abstract

Predicting drilling fluids rheology is crucial to control/optimize the drilling process and the gas extraction from drilling fluids in logging systems. A Couette viscometer measured the apparent viscosity of a bentonite mud at various shear rates and temperatures. The bentonite mud behaved as a yield-pseudoplastic fluid, and a modified Herschel-Bulkley model predicted the shear rate and temperature effects upon the shear stress. A pipe viscometer was built to seek a correlation between the mud flow rate and the pressure drop and thereby determine refined Herschel-Bulkley parameters. Coupling a rheological model to a pipe viscometer enables the continuous acquisition of apparent viscosities of Newtonian or non-Newtonian fluids at a rig-site surface.

Elastoviscoplasticity, hyperaging, and time–age-time–temperature superposition in aqueous dispersions of bentonite clay

“…This journal is © The Royal Society of Chemistry 2023 40 1C, depending on the geographical location. 27 This observed temperature dependence of yield stress is in agreement with other studies of bentonite dispersions, 7,22,55 and is thought to result from increases in thermal motion accelerating the formation of EF and EE associations, driving the glassy microstructure deeper into a state of low free energy and leading to a more stable gel structure. 4.1.2 Transient yielding during creep.…”

“…where t w is the time elapsed between the cessation of preshear and the beginning of an experimental measurement, and t is the total elapsed time since the cessation of preshear. For t 4 t w , eqn (27) makes clear that the elapsed material time t ˜is nonnegative and increases (nonlinearly) with laboratory time scale t.…”

“…The dependence of the material time interval t ˜on the elapsed laboratory time t À t w since the beginning of an experiment at time t = t w is illustrated in Fig. 12, which plots eqn (27) for a set of distinct age times t w . Each of these curves is observed to approach an asymptote as the wall clock time t -N. The asymptotic value can be derived by direct inspection of eqn (27) in that limit:…”

“…12, which plots eqn (27) for a set of distinct age times t w . Each of these curves is observed to approach an asymptote as the wall clock time t -N. The asymptotic value can be derived by direct inspection of eqn (27) in that limit:…”

Preparation and Characterization of Chitosan/Hydroxypropyl Methylcellulose Temperature-Sensitive Hydrogel Containing Inorganic Salts for Forest Fire Suppression

“…The high correlation coefficient (R 2 > 0.99) suggests a strong relationship, indicating that the hydrogel behaves as a yield pseudoplastic fluid [ 46 ]. This behavior has significant implications, as it implies that the hydrogel does not flow until a critical stress (i.e., the yield stress) is exceeded, highlighting its potential for effective deployment in fire suppression scenarios, where rapid activation is essential.…”