Treatment method of oil field oil displacement agent rhamnolipid fermentation broth

The invention relates to a treatment method of an oil field oil displacement agent rhamnolipid fermentation broth. The method comprises the following steps: (1) centrifuging the rhamnolipid fermentation broth to obtain a fermentation broth and a precipitation layer; (2) filtering and concentrating the fermentation liquor in the step (1) by using a ceramic membrane, and respectively obtaining filtrate and concentrated liquor after the concentration is finished; (3) treating the precipitation layer in the step (1) and the concentrated solution in the step (2) to a nanoscale to obtain a nanoscaleparticle mixture in a range of 10-80nm; and (4) uniformly mixing the nanoscale particle mixture obtained in the step (3) with the filtrate obtained in the step (2), and carrying out low-intensity ultrasonic treatment, and carrying out ultrasonic treatment to obtain the composite surfactant. The surfactant has low surface tension and interfacial tension and good temperature resistance and salt resistance, can significantl