Assessing the Reliability of Physical Non-Newtonian Fluid Models for Saline FLOPAAM Polymer Solutions

Abstract

Experiments were conducted to investigate the impact of salt (NaCl) on rheological properties of specifically FLOPAAM 5115 VHM and FLOPAAM 3630-S polymers. These polymers were dissolved in brines of various salinity levels ranging from 0 to 20 g/l of NaCl. The experiments were comprised of steady shear ramping, start-up and cessation tests using advanced rheometer with a cone and plate tool. Apparent viscosity and shear stresses were recorded at various step shear rates.

The data obtained from these tests were graphically presented and analyzed. Additionally, the scope of this theses was to investigate the reliability of physical non-Newtonian fluid models and their capability to predict the behavior of complex fluids. The models involved in this work are LPTT, EPTT, FENE-P and C-FENE-P. These models were fitted against the experimental data for qualitative and quantitative analysis.

Results of the experiment showed that the salt has a stabilizing effect on the polymers’ viscosity as well as a dampening effect on shear stress growth and a greater decay of shear stress for the cessation test. These effects amplifies with increasing salt content. Furthermore, the data fitting showed interesting results, especially for the C-FENE-P dumbbell model. As it has proven itself capable of predicting viscosity of saline solution very well, something which cannot be said for shear stress, which has shown to be sensitive to the approach used for the applying such models.