Improved Oil Recovery (IOR) Definition / Meaning

Improved Oil Recovery (IOR) encompasses a broad set of reservoir management techniques and technologies applied after primary production to increase the amount of oil that can be extracted from a reservoir. IOR is not a single method but a philosophy of proactive intervention—ranging from optimized waterflood patterns and infill drilling to advanced reservoir surveillance—to maximize the economic life of an oil field. While often used interchangeably with Enhanced Oil Recovery (EOR), IOR technically includes methods that improve sweep efficiency and well productivity, whereas EOR specifically alters fluid properties (e.g., viscosity, interfacial tension) to recover remaining oil. In practice, IOR is the umbrella under which EOR resides.