Influence of Formate Concentration on the Rheology and Thermal Degradation of Xanthan Gum

Abstract

Xanthan gum solutions have gained increasing interest for their use as environmentally friendly chemicals in the oil industry. Xanthan is compatible with most concentrate brines used for controlling formation damage and fluid loss. Particularly, formate brines reinforce the ordered structure of the biopolymer in solution, gel strength, and the specific gravity of the resulting fluid. In this paper, we studied the effect of thermal aging on the rheological behavior of xanthan solutions as a function of the concentration in potassium formate. Ionic strength below a threshold concentration does not prevent the degradation of the structure of xanthan after being submitted to aging at 165 °C. Aged solutions show an important loss of strength in their mechanical properties, lower pH, and higher content in furfural and hydroxymethylfurfural. Highly concentrated formate brines are necessary to maintain the strength of the rheological properties after exposure to high-temperature environments.

Thermal and Rheological Properties of Hydrophobic Nanosilica in Sunflower Oil Suspensions at High Pressures

“…Drilling fluids are classified as water-based mud (WBM) and oil-based mud (OBM) according to the nature of its continuous phase. Despite WBM having economic and environmental advantages over OBM [3][4][5][6][7], in challenging wells OBM present technical advantages thanks to intrinsic oil properties such as high thermal stability, lubricity, and shale inhibition [8,9]. In the context of environmental concerns, fluids having a low-toxicity continuous phase such as vegetable oils and derivatives are more suitable [10].…”