Oily Wastewater Filtration Treatment Technology Research

Considerable oily sewage is produced during oil&gas exploitation and development phase, such as produced water in multipurpose Station, backwater from flushing fluid, and discharge water out of well-drilling so on. In the meanwhile, substantial water is produced from oil wells at later stage of oilfield development, therefore, formation pressure depletes. In view of pressure-upkeeping, plenty of water will be injected into wellbore. Water produced out of oil& gas wells is disposed and then is reinjected into production wells. On the one hand, formation pressure will be upkept, production rates is maintained. On 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 ont only of vitally social consequence, but also of gigantically economic consequence.Filtration treatment relevant technologies on oily sewage are investigated in this paper. Firstly filtering procedure mechanism is developed. From microcosmic point of view, removal procedure of suspended matters in oily sewage consists of its transferring, adhesion and its desquamation. Contaminants' adhesion to filtering material surface mainly relies on two functions: when suspended matter is near to filtering material surface, vandevann gravitation is greater than expulsive force of electrical double layer, so, contaminants adhere to filtering material surface. The other adhesion type is developed through bridge function of macromolecule matters between suspended particles and filtering material surface. The transferring procedure includes screening and filtering, intercepting, inerrancy, precipitation, diffusion and dynamic effects.Filtered process mathematical model includes material balance equations of solid filter material and liquid sewage respectively. Finite difference method and characteristic method are employed for solving these equations (simplified and general models). Three algorithms (FDM for simplified and general models, MOC for general models) are used for solving and simulating filtered process of stationary beds. And then volume fraction and specific sediment quantity of suspended solid in the terminal point of stationary bed simulation, are viewed as initial condition, filtering procedure simulation of moving beds is carried through.Considering that there exist complicated and random factors in filtering operation process, further study of filtering procedure recurs to experimental media. Therefore, filtering procedure of moving bed and filter material regeneration process are investigated in-house experiments. These results will provide certain basis for filtering process design, and will also provide somereference for filtering material regeneration modes of continuous filtration technology, simultaneously can provide optimizing configuration between regenerative device structure and working parameters.Filter material regenerating mechanisms are investigated in the following chapter. During filtering material backwashing, elimination of suspended matters from filter material particles surface will be affected by rubbing effects, between hydraulic flow shearing forces and filtering material particles, and between particles and solid surfaces, nevertheless, what are the leading effects will depend on backflushing working conditions. The three regeneration methods of filter material, including fluidization, hydraulic vortex flow and mechanical rabbing, are expatiated in detail. Simultaneously turbulent flow mechanics and liquid/solid two-phase flow theories are applied to establish turbulent flow dynamical equations of sewage and motion equations of filtering particles in the process of filtering. Definite condition and computation methods are developed and established in this chapter.To understand folly regenerator structure's influence on regenerator, according to hydraulics principles and observation in computing results, more than ten regenerators of structure are designed. And then simulation computations are done on these regenerators. Scores of structure sizes are analyzed. By analyzing motion trajectory of particles and flow field of regenerators, combining with other regenerative devices' results, conclusions of design proposal are drawn in the last of this paper.