Albizia amara leaf powder as a next-generation biodegradable additive for advanced drilling fluid applications.

The environmental and health risks associated with traditional nanoparticle-based drilling fluids have made the development of ecologically sustainable drilling-fluid additives crucial. This study examined a novel biodegradable additive made from Albizia amara leaves as a way to improve the rheology and filtration of water-based drilling fluid (WDF). XRD, SEM, FTIR, and TGA tests were used to characterize the obtained Albizia amara powder. While TGA showed outstanding thermal stability with 92% mass retention up to 225 °C, XRD verified the powder's crystalline composition. Rotational, oscillatory, thixotropic, and filtration analyses were used to assess the additive's performance at 30 °C, 70 °C, and 110 °C after it was added to WDF at concentrations of 0.5, 1.0, and 1.5 weight percent. When compared to the base mud at 30 °C, the formulation with 1.5 weight percent Albizia amara performed the best, increasing viscosity by up to 95% and shear stress by 58%. The optimized formulation only reduced viscosity by 20-28% at high temperatures (110 °C), while the standard WDF showed a drop of up to 47%, indicating better thermal stability. The optimized formulation's storage modulus increased significantly from 21.54 Pa for the basic mud to 40.7 Pa for oscillatory rheology, indicating improved elasticity and anti-sagging behavior. While the basic mud only recovered 74.9% of its initial viscosity, thixotropic experiments showed full structural recovery at 118 s at increased temperatures. Additionally, filter-cake thickness decreased from 4.5 to 2.0 mm, and API fluid loss dropped from 7.45 mL for the normal WDF to 5.45 mL for the optimized formulation. The study presents Albizia amara as a viable option for HPHT drilling applications since it is an affordable, environmentally friendly, and sustainable bio-additive that can simultaneously enhance rheological stability, cuttings suspension, thermal resistance, and filtration control in water-based drilling fluids.