# Comparative Evaluation of Xanthan Gum, Guar Gum, and Scleroglucan Solutions for Mobility Control: Rheological Behavior, In-Situ Viscosity, and Injectivity in Porous Media

## TL;DR

This study compares three biopolymers for improving water injection in oil recovery, focusing on their viscosity and injectivity in carbonate reservoirs.

## Contribution

The paper provides a comparative analysis of Xanthan Gum, Scleroglucan, and Guar Gum under reservoir conditions for polymer flooding applications.

## Key findings

- Xanthan Gum showed the highest viscosity increase and strongest shear thinning behavior.
- Scleroglucan provided stable viscosity and moderate permeability impairment.
- Guar Gum offered predictable but lower viscosity enhancement compared to the other polymers.

## Abstract

Water injection is the most widely used secondary recovery method, but its low viscosity limits sweep efficiency in heterogeneous carbonate reservoirs, especially when displacing heavy crude oils. Polymer flooding overcomes this by increasing the viscosity of the injected fluid and improving the mobility ratio. In this work, we compare three biopolymers (i.e., Xanthan Gum, Scleroglucan, and Guar Gum) using a core flood test on Indiana Limestone with 16–19% porosity and 180–220 mD permeability at 60 °C and 30,905 mg/L of salinity. We injected solutions at 100–1500 ppm and 0.5–6 cm3/min to measure the Resistance Factor (RF), Residual Resistance Factor (RRF), in situ viscosity, and relative injectivity. All polymers behaved as pseudoplastic fluids with no shear thickening. The RF rose from ~1.1 in the dilute regime to 5–16 in the semi-dilute regime, and the RRF spanned 1.2–5.8, indicating moderate, reversible permeability impairment. In-site viscosity reached up to eight times that of brine, while relative injectivity remained 0.5. Xanthan Gum delivered the highest viscosity boost and strongest shear thinning, Scleroglucan offered a balance of stable viscosity and a moderate RF, and Guar Gum gave predictable but lower viscosity enhancement. These results establish practical guidelines for selecting polymer types, concentration, and flow rate in reservoir-condition polymer flood designs.