نوع مقاله : مقاله پژوهشی
نویسندگان
دانشکده مهندسی، دانشگاه شهید چمران اهواز، اهواز، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
In overbalanced drilling operation, due to the pressure difference between the drilling
fluid and formation mud filtration happens in which a layer of cake develops on the sides of a wellbore
wall. In this research a numerical procedure was used for modeling and simulation of the cake growth
in which at first, three-dimensional flow field of non-Newtonian drilling mud has been computed using
finite difference scheme and using bipolar coordinate. Next, permeation flux of the filtrate is evaluated
using the Darcy equation and the rate of cake growth has been calculated based on the probability of
particle adhesion and using an explicit 4th order Runge-Kutta method. In the present paper, the effects
of drill string rotation, eccentricity and particle radius on the cake thickness and permeate flux are
studied. The results show filter cake thickness and filtrate flux remains invariable by increasing drill
string rotation due to drilling fluid recirculation in the annulus. Increasing eccentricity not only changes
the profile of filter cake thickness and filtrate flux but also increases the difference between its maxima
and minima. Furthermore by decreasing particle size, the filter cake thickness increases and filtrate flux
decreases.
کلیدواژهها [English]