DRAG-REDUCING AGENT FOR USE IN INJECTION WATER AT OIL RECOVERY

摘要

A drag-reducing agent in an amount of 50-400 ppm in water having an electrolyte content of 0.01-7% by weight includes two zwitterionics, each including acyl containing surfactant and an anionic surfactant, where the hydrophilic group is a sulphate, a sulphonate or an ether sulphate. The water containing the drag-reducing agent is suitable to be used in injection water at oil recovery.