Investigating the thermal effect on the flow characteristics of acrylamide-based polymer modified bentonite drilling mud using upper shear stress limit

摘要

In this work, the effects of hot-aging on the rheological characteristics of acrylamide-based tetrapolymer modified bentonite drilling mud were examined. The dosage of the acrylamide-co-sodium 2-acrylamido-2-methylpropanesulfonate-co-N-vinyl pyrrolidone-co-N-butyl propenoate (ASAPB) in the drilling muds was varied from 0 to 1 wt.% under geothermal condition ranging from 25 degrees C to 150 degrees C. The rheological behaviour of ASAPB modified bentonite drilling mud were quantified using Vipulanandan model and compared with Herschel-Bulkley model. The Herschel-Bulkley model predicted satisfactorily the shear thinning relationship between the shear stress and shear strain rate. However, Vipulanandan has a maximum shear stress limit whereas the other did not.