Numerical Simulation of Drilling Fluid Behavior in Different Depths of an Oil Well

Abstract

When drilling an oil well, a viscous fluid is injected to aid drilling. This fluid is also responsible for removing the cuttings and maintaining structural stability of well. The rheology of this drilling fluid has a direct influence on the cleaning of the well, on the dynamics of the fluid in pipe and annular areas. Linear mathematical extrapolations for high pressure and high temperature environments can lead to rheology errors up to 75%. In this study, a finite volume model was developed to simulate the flow of a waterbased mud in annular and jetting environments in the drilling environment. Annulars were made by steel pipes and permeable formations. The fluids evaluated were developed empirically with xanthan gum and bentonite clay. The numerical results are consistent with literature and represent characteristics of a Yield Power Law fluid and a Bingham plastic. A comparison was made with water, allowing a correlation between rheological effects and fluid dynamics in annular and high vorticity regions.

Numerical Simulations of the Flow of a Dense Suspension Exhibiting Yield-Stress and Shear-Thinning Effects

“…The flow behavior of a yield stress fluid is difficult to predict, as it usually involves solid to fluid transition and shear thinning effects; these effects cannot be simply predicted a priori without the help of numerical simulations [12]. Based on the experimental tests, Gomes et al [13] developed a finite volume model to study the flow of a Bingham plastic and a Herschel-Bulkley fluid in annular and jetting regions. Their numerical simulations agree with the results presented in the literature, indicating that numerical simulations supported by reliable experimental data can effectively promote the study of flow under extreme conditions.…”