Optimization of Water-Based Drilling Mud Performance Through the Integration of Xanthan Gum and Natural Zeolite as a Composite Viscosifier

Abstract

The increasing demand for ultra-deep reservoir development has driven the need for high-performance water-based drilling fluids that can maintain stability under high-pressure and high-temperature (HPHT) conditions. This study investigates the integration of xanthan gum with natural zeolite, forming composite viscosifiers through blending and grafting methods, to enhance the rheological and filtration properties of drilling muds. The ZXG composites were synthesized and incorporated into drilling fluid systems, then evaluated under both ambient and simulated HPHT conditions (150 °C for 16 hours). Rheological tests using a rotational rheometer measured plastic viscosity (PV) and yield point (YP), which are critical indicators of cutting transport and suspension capacity. Results showed that the physically bonded composites, particularly Z-XG (Blending) and Zeolite + Xanthan Gum (XC), exhibited superior rheological performance compared to the baseline and grafted formulation. These samples demonstrated higher PV and YP values before thermal aging and retained better flow properties after hot rolling, indicating improved thermal stability. In contrast, the grafted Z-XG formulation showed significant performance degradation. The study concludes that physically blended xanthan-zeolite systems are more effective than chemically grafted alternatives in improving drilling fluid resilience under HPHT environments.