Novel Equation for the Prediction of Rheological Parameters of Drilling Fluids in an Annulus

Abstract

Several well-known correlations such as the Bingham-plastic, power-law, and Herschel−Bulkley models have been used so far to determine the rheological parameters of drilling fluids. For some particular fluids, however, even a three-parameter model such as Herschel−Bulkley does not exhibit appropriate behavior. On the other hand, determination of the rheological parameters by numerical methods such as nonlinear regression may provide meaningless values, i.e. negative yield stresses. This is particularly notable in determination of yield stress, which identifies the capacity of the drilling fluid to carry the cuttings. In this work, a new equation has been developed which is capable of determining the rheological parameters and, more particularly, the yield stress of drilling fluids. It is demonstrated that the developed correlation improves the prediction of the rheological parameters of the fluids by including a logarithmic term. The velocity profiles and pressure drop values obtained for several drilling fluids in an annulus geometry exhibit the suitability of this novel equation in comparison with the previously mentioned equations.

Cellulose Nanoparticles as Modifiers for Rheology and Fluid Loss in Bentonite Water-based Fluids

“…Among these models, Bingham, power-law and HerschelBulkey models are commonly used. 35 The Bingham plastic model is given by Equation 2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 where is the shear stress, 0 is the yield stress or yield point, is the plastic viscosity, and ̇ is the shear rate.…”

Rheology and Temperature Dependency Study of Saraline-Based Super Lightweight Completion Fluid

“…2. The reasons for this poor prediction of the Ostwald-de Waele model are, first, the shear rate versus shear stress behaves linearly at a lower shear rate, and, second, it is due to the nonexistence of a yield point parameter in the model; this explains the poor prediction of the Ostwald-de Waele model (Nasiri and Ashrafizadeh, 2010). The SSE and RMSE were considerably very low (1.03 and 1.33, respectively).…”

Rheology, stability and filtration characteristics of Colloidal Gas Aphron fluids: Role of surfactant and polymer type

“…The Power Law model had performed well in predicting the rheological behavior of CGA based drilling fluids compared to the Bingham plastic and Casson models. The low error of the Power Law model in predicting the rheological behavior is due to the lack of a yield point parameter in this model (Nasiri and Ashrafizadeh, 2010). Also, as can be seen in …”