Research On Oil/Water Separation Characteristic And Treatment In ASP Produced Water

As quick development of the national economy, the oil demand has risen increasingly. It was focus on Enhancing the oil exploitation ratio in existing oilfields for alleviate the contradiction between the oil apply and demand. The tertiary oil extraction technology will be the universal means of oil exploitation in 21st century; it is of important strategic meaning.In recent years, technologies for tertiary oil extraction have been developed in Daqing oilfield. Several methods involved in, polymer flooding and ASP (alkaline, surfactant and polymer) flooding have been used to enhance the oil exploitation. ASP flooding technology was developed recent years, which has been found to enhance oil recovery by 17%~20% and 10% than that of water flooding and polymer flooding respectively. Due to the use of alkaline, surfactant and polymer in the injected water in ASP flooding technology, wastewater from ASP flooding process contains some residual chemicals and it is more difficult to treat than that from water flooding. It is of important meaning to study on the oil /water separation characteristic and the influencing factors.In this experiment, the quality and oil/water separating characteristic was studied to define the major factors which effect the treatment of ASP flooding produced water, then study on the effect of factors on oil/water separation of simulated ASP flooding produced water. The stability mechanism of oil drops was showed up according to the analyzing of Oil-water interfacial characteristic, based on which, some effective methods were put forward to treat ASP flooding produced water. The major contents of this research are following:1. Analyzed the effect of water quality on oil/water separation, determined the main influencing factors. It was showed that ASP content; oil content and size of drops are main influencing factors2. Studied on the effect of factors such as ASP content, oil content, size of oil drops and icon concentration on oil/water separation of simulated ASP flooding produced water. Effct of polymer on the oil/water separation is more than that of surfactant and alkali according to the results;3. Researched on the effect of alkaline, surfactant and polymer on water phase rheology, tested Zeta potential in oil-water interfacial electrical double layer. High vicidity caused by polymer and lowerm Zeta potential caused by surfactant and alkali made the drops more stable.4. Some methods such as centrifugal, flocculating-flotation, ultrasonic and electrolytic methods are used to treat the ASP flooding produced water. All the methods treat the ASP flooding produced water effectively.