Research & Development On Integrated Processes And Equipment Of Oily Wastewater Treatment

Considerable oily sewage is produced during oil & gas exploitation and later development phase especially, the percentage of produced water reaches up to 90%. In order to keep pressure, plenty of water will be injected into wellbore. Water produced out of oil & gas wells is disposed and then is re-injected into production wells. On the one hand, formation pressure will be up-kept, production rates is maintained. The other hand, the quality of sewage discharge will decline. There exists the balance between productions and injections. It is of vital industrial and environmental consequence. As for oily sewage disposal and reinjection into oil wells, it is not only of vitally social consequence, but also of gigantically economic consequence.Various traditional approaches to treat oily wastewater are discussed in detail. On the base of this, "coalescence-destabilization-high efficiency air flotation-fine filtration" comprehensive integrated oily wastewater treatment processing equipment has been brought forward and developed. The mechanisms of coagulation and fine filtration procedures are developed. And the coagulation tank, coalescence tank, filtration tank are designed carefully. Based on a number of tests, some substance which with inhomogeneous surfaces are selected to prepare coalescers modification used in the processes such as coalescence and fine filtration. Thus the integrated equipment is designed and developed. The pilot test was conducted in Jianghan oil field and a number of technical data has been gained. The device structure and working parameters has been optimized in the test and many suggests for further improvement has been proposed, which can provide certain basis for oily wastewater treatment equipment design hereafter.Through the pilot tests conducted in Jianghan oil field, the analyzing data of effluent quality in the coagulation, coalescence and filtration processes have gained and the results proved the ceramics medium made in Shangdong Alum Plant has sound effects of treating oily wastewater by design inner structure of tanks dedicatedly and be worthy development and promotionFinally, the benefit of the comprehensive treatment equipment is evaluated. Experiments show that this equipment has pretty high social, economic and environmental values. Suggestions have been given for further research & application and future development has been oriented.