Study On Generation And Control Of New Mineral Particles In ASP Flooding Produced Water

As one of the most important EOR technologies, ASP flooding enhances oil recovery, but it also increases the content of suspended solid as well as making the removal of suspended solid more difficult, which leads to that treated produced water can't reach recycle standard.Therefor, it has important significance to reduce treatment difficulty of ASP flooding produced water for studying the source, influencing factors and the source control method of suspended solid.In this thesis, effect of new generated mineral particles on suspended solid of ASP flooding produced water was revealed, through testing content of suspended solid, as ASP flooding produced water from the N1FE Block field trial was settling and the produced water filtered by membrane was aging. Through calculating supersaturation quantity of inorganic minerals in ASP flooding produced water and simulating aging experiments of produced water, the main factors that influenced on new mineral particles generation of ASP flooding produced water were determined. On the basis, the water stabilizer formula was optimized, which could control effectively generating new mineral particles of produced water from the N1FE Block field.The reasons that lead to high content of suspended solid and difficulty of removal were the precipitation of new mineral particles by supersaturation of alkaline earth metal carbonates and SiO2 of ASP flooding produced water.The main factors that influenced on the generation of new mineral particles included the content of alkaline earth metals, silicic acid radical ions and partially hydrolyzed polyacrylamide, alkalinity, pH and temperature. Among them, the increase of the content of earth metals and partially hydrolyzed polyacrylamide, alkalinity, pH and temperature could promote the precipitation of alkaline earth metal carbonates. But the increase of the content of silicic acid radical ions, partially hydrolyzed polyacrylamide and temperature as well as the reduction of pH could promote the precipitation of amorphous SiO2 particles.By adding 25mg/L water quality stabilizer WSBL-3 to ASP flooding produced water from the N1FE Block field, the precipitation of new mineral particles could be effectively controlled, thus the content of suspended solid and difficulty of elimination were obviously reduced.