Oil production in high-salinity reservoir remains challenging due to limited wettability alteration and poor chemical agent performance under harsh reservoir conditions. This study aimed to develop and evaluate a biodegradable composite comprising polylactic acid (PLA) and Henna (PLH) as a multifunctional agent capable of reducing interfacial tension (IFT), altering rock wettability, and improving mobility control. The PLH composite was synthesized through controlled melt processing, with reproducibility confirmed by FTIR, EDS, and SEM analyses across multiple fabrication runs. Its physicochemical effects were assessed via IFT measurement, rheological characterization, wettability tests, and core flooding experiments using formation water (FW), seawater (SW), and PLH-modified brines under HPHT conditions. Optimal PLH concentration (2 wt%) delivered significant IFT reduction (up to 34 % in SW), increased viscosity and yield stress consistent with Bingham plastic behavior, and pronounced wettability alteration toward water-wet conditions. Core flooding with 2 wt% PLH-SW achieved a tertiary recovery factor of 80.5 %, outperforming FW and SW due to synergistic chemical and physical mechanisms, including controlled high-permeability channel diversion. Particle size stability (<100 nm) ensured injectivity in the tested sandstone cores. Compared with prior EOR agents, PLH exhibited competitive recovery performance, environmental compatibility, and cost advantages. Findings support its potential as a sustainable, multi-mechanism EOR material for high-salinity reservoirs, warranting pilot-scale evaluation and extended reservoir aging studies. • Polylactic Acid (PLA)/Henna composites as an environmentally sustainable additive to enhance oil recovery • Physicochemical effects were assessed via IFT measurement, rheological characterization, wettability tests, and core flooding experiments • Compared with prior EOR agents, PLH exhibited competitive recovery performance
Alkhrissat et al. (Fri,) studied this question.