This article summarizes a concise investigation on the effect of concentration of the four main components of a novel lightweight drilling fluid, i.e., glass bubbles, xanthan gum, starch, and clay, to the Herschel-Bulkley rheological model parameters. The three parameters of Herschel-Bulkley model, i.e., yield stress, fluid consistency, and fluid index were calculated by fitting the experimental data of shear stress as a function of rate of shear to the model. Results indicate that the increment of the amount of four main components increase the yield stress of the final fluid as the flow resistance is increased. Furthermore, the result also showed that the calculated fluid consistency of the drilling fluid appears to be strongly dependent on the presence of glass bubbles, xanthan gum, and clay. However, the fluid consistency appears not to be affected by the presence of starch. It is also concluded that the presence of glass bubbles, xanthan gum, and clay in the fluid tends to determine the final fluid to behave as pseudoplastic. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012