An Experimental Analysis of the Transport of Drilled Particles

Abstract

Abstract An experimental apparatus was developed to determine the settling velocity of drilled particles in a Newtonian fluid and also to study the transport of drilled particles in an annulus using both water and drilling mud. Correlations were developed for the settling velocity of the drilled particles and for the recovery fraction of the drilled particles subjected to turbulent flow of water in an annulus. The introduction of pipe rotation and drilling muds produces changes pipe rotation and drilling muds produces changes in the recovery fractions compared to the recovery fractions observed in the case of water where no pipe rotation is performed. No correlations were pipe rotation is performed. No correlations were developed, and the data is treated only qualitatively in these cases. Introduction The ability of a drilling mud to remove drilled particles (cuttings) from a wellbore annulus has particles (cuttings) from a wellbore annulus has been discussed by various authors, Williams and Bruce, Pigott and Hall, Thompson and Nuss. The extension of this work to predict the net upward velocities of irregular shaped particles from various settling velocity equations has yielded inconclusive results with large differences between expected and observed values. Some explanation for these differences has been given, but further attempts to predict rise times under actual or simulated conditions have not been made. By simulating a wellbore annulus in the laboratory, I have attempted to extend the present knowledge and present empirical relationships, when possible w predict the recovery fractions for drilled particles in a wellbore simulated annulus. THE EXPERIMENT LABORATORY FACILITIES The laboratory data were taken from two different apparatus. For obtaining the settling velocities of the drilled particles, a 15-ft long, 3-in. ID glass tube was used. Along its length, four measuring stations were marked; the times for a particle to reach the respective stations were measured with electric timers accurate to within 5/100 second, (Fig. 1). SPEJ P. 39