Rhamnoilpid Bio-surfactant Composite Flooding Test Resuts and Understanding

Close spacing bio-surfactant tertiary composite flooding pilot test indicated, compared to tertiary composite surfactant system without adding bio-surfactant, usage of sulphonate surfactant and cost of injected chemical decreased respectively by 1/2 and 30% for bio-surfactant tertiary composite system, which is formed by rhamnoilpid bio-surfactant and sulphonate surfactant. The ultra-low interface tension value between flooding system and crude oil reached 10-3mN/m, and recovery factor for central well site and that for overall area increased by 23. 24% and 16. 34% , respectively.