The Chemical Enhanced Oil Recovery (EOR/IOR) employs three main categories of chemicals: polymers, surfactants, and alkali agents. Polymers increase the viscosity of injected water, reducing fingering and improving sweep efficiency. Surfactants lower interfacial tension between oil and water, mobilizing trapped oil droplets. Alkalis react with acidic components in crude oil to form natural surfactants, further improving displacement efficiency.

The process typically begins after conventional recovery methods decline. Chemicals are injected in controlled concentrations, often in combination with water flooding, to mobilize and push residual oil toward production wells. Advanced formulations and nanotechnology are being developed to improve chemical stability under high-temperature and high-salinity conditions.

The success of chemical EOR depends on careful reservoir evaluation, cost management, tertiary oil recovery, polymer flooding, surfactant injection, chemical EOR methods, improved oil recovery techniques and chemical compatibility. With advancements in computational modeling and laboratory testing, operators can now design highly customized EOR solutions to maximize field productivity.