Abstract

ROJAS, MARIO et al. Transport of solids in solutions of biopolymer mixtures and improvements to their distribution in a flow simulator in vertical conduits with annular cross section. Rev. Fac. Ing. UCV [online]. 2008, vol.23, n.3, pp.43-51. ISSN 0798-4065.

This paper compares the results on suspension and transport of solids in two experimental flow simulators in vertical ducts with annular cross section. In both cases, non-Newtonian biopolymer solutions were used as the liquid phase. The biopolymers used were xanthan gum and guar gum, and the solid phase was silica sand with an average particle size of 250 ìm. The first experimental system used was based on a 3-m height concentric pipe with a 0.15 m hydraulic diameter. The second equipment was built by changing the dimensions of the first system to a height of 6 m and a 0.10 m hydraulic diameter. These changes were made so that the solid phase would distribute better throughout the whole system. Both units simulate a well drilling process at room temperature and without the effect of drill bit rotation. The most important variables studied were annular velocity and polymer concentration. Significant improvements were obtained in solids transport when changing the solids distribution pattern in the system and the geometrical characteristics of the annulus. Furthermore, the xanthan-guar gum mixture solutions with a higher proportion of guar gum have a higher solids transport capacity than pure polymer solutions; there is an important synergistic effect from the point of view of the use of these polymers as viscosifying additives for drilling fluids.

Keywords : Non-Newtonian fluid; Liquid-solid flow; Guar gum; Xanthan gum.