Surfactant flooding is an enhanced oil recovery technique that uses surfactants, which are compounds that lower the surface tension between liquids. By injecting these surfactants into oil reservoirs, they help to mobilize trapped oil, making it easier to extract. This method is particularly useful in reservoirs where traditional extraction methods are less effective. The process involves mixing surfactants with water and injecting this solution into the reservoir. The surfactants reduce the interfacial tension between the oil and water, allowing the oil to flow more freely towards production wells. This technique can significantly increase the amount of recoverable oil from fields, improving overall efficiency in the oil industry.