This comprehensive book examines advanced Enhanced Oil Recovery (EOR) methodologies utilizing nanoparticles, polymers, and surfactants as extraction efficiency becomes increasingly critical in depleting oil reserves. The text provides a systematic analysis of how these chemical agents function to reduce interfacial tension, modify wettability parameters, and enhance oil displacement mechanisms in challenging reservoir environments. The authors present an integrated framework connecting theoretical principles with laboratory investigations and field implementations, addressing both the technical challenges and economic considerations of modern EOR applications. • Offers an analytical examination of nanoparticle-polymer-surfactant synergistic effects in maximizing recovery efficiency in mature and low-permeability formations. • Features documented case studies demonstrating quantifiable outcomes in diverse reservoir conditions. • Provides a systematic analysis of wettability alteration mechanisms, interfacial tension reduction, and sweep efficiency optimization. • Investigates disjoining pressure phenomena and snap-off mechanics affecting multiphase flow in porous media. • Evaluates environmental impacts and economic viability of advanced EOR implementations. • Identifies emerging research directions and technological innovations in chemical EOR applications. This scholarly reference serves researchers and practitioners across multiple disciplines, including graduate-level petroleum and chemical engineering programs, research scientists specializing in nanotechnology, polymer science, and colloid chemistry, and technical professionals engaged in reservoir engineering and field development. The methodological approaches and analytical frameworks presented are particularly relevant for research institutions, oil companies, and professional engineering organizations seeking evidence-based strategies to address the technical challenges of contemporary oil recovery operations.