Effects of clay contamination on the seepage flow ofPartially hydrolyzed polyacrylamide (PHPA) polymer

Abstract

Constructions of large bored piles in Bangkok subsoils require drilling fluid for stabilizing boreholes. Partially hydrolyzed polyacrylamide (PHPA) polymer is a popular fluid used nowadays. Since the permeation rate in to the ground of PHPA polymer fluid is relatively high, a considerable fluid loss occurs during construction. This research studies the rheological properties of PHPA polymer fluid which is vital for describing its seepage behavior through the ground. Since the PHPA polymer slurry can be contaminated by clay particles when drillings are performed through the Bangkok clay layer, the effects of clay contamination on the rheological properties of the PHPA polymer fluid is also carried out in this study. The experiments are performed on the PHPA polymer fluids at various concentrations with and without clay particles by a rheometer. The results are used for determining the relationship between viscosity and shearing rate of the fluids and proposing a mathematical model which can describe the rheological properties of contaminated PHPA polymer fluid.