The Study On Treatment Of Produced Water And The Way Of Improving Water Quality In Aijiawan Oil Gather Station

The waste water processed in Aijiawan oil gather station is mainly Chang -2 production fluid. This gather station has a treating capacity of 750-850m3 oil-water mixture and 450～480 m3 waster water after the oil-water separation every day.10%～11% produced water is re-injected effectively.Now, there is no any waste water treatment facility in Aijiawan oil gather station. The water from dehydrating of crude oil and domestic sewage mixed by 500 m3 sewage tank are directly re-injected. According to statistical data from 2007.1 to 2007.12, there are following problems in Aijiawan oil gather station:1. Average concentration of suspended solids in waste water is 202.21mg/L, which far exceeds the guide posts of oil field company (suspended solid content<10.0 mg/L).2. Average concentration of oil content in waste water is 160.00 mg/L, which far exceeds the guide posts of oil field company(oil content<10.0mg/L).3. Average concentration of sulfide in waste water is 20.38mg/L and the top is 99.0mg/L, which far exceeds the guide posts of oil field company(sulfide content<2.0mg/L).4. Bacterial content in waste water is high, which far exceeds the guide posts of oil field company (SRB<10/ml, Saprobe<100/ml).5. There are certain corrosion and scaling phenomena in swage system. Since Aijiawan oil gather station has worked, the pipeline before water injection pump appears holes in many different areas.According to main problems which exist in produced water reinjection system and based on analyzing and monitoring nature of waste water, this article research the reason why the produced water does not get the quality; find out the means that could prevent corrosion; and select and evaluate suitable bactericide and scale corrosion inhibitor. So we can improve the injection water quality and cut their treatment costs.