CHARACTERIZATION AND INTEGRATED UTILIZATION OF WASTEWATER FROM OIL PRODUCTION STATIONS IN SHENGLI OIL FIELDS

Shengli oil fields are one of the most important petroleum occurring areas. Its geothermal resources are abundant. With the background of energy saving, wastewater from petroleum producing is of relatively high-temperature. It can be used for water flooding, space heating and bathing. Wastewater samples from 19 typical oil production stations of seven oil factories in Shengli oil fields are obtained. Water chemical compositions are analyzed by ion chromatography. Scaling tendency corrosion of wastewater are also discussed. Results show that the pH of wastewater is 6.8-8.0 and the average is 7.4. It is saline water-brine with TDS ranging from 6.0gL-1 to 59.7gL-1. The wastewater is rich in Li, Mn, Cr, Ni, Cu, Zn and Sr. The microelements of Li and Sr are in particular rich. Its average concentrations are 1mgL-1 and 70.5mgL-1,which satisfy the mineral water requirement but cannot be used for minerals exploitation. Corrosive efficiency factor, larson and reruo method are used to assess the corrosion of wastewater. Results indicate that the wastewater is strongly corrosive, which is caused by chloride ion. Carbonate, sulfate and silicate scale are assessed using references from GB-T-11615-2010. The results indicate that carbonate and silicate scale won't occur while sulfate scale would form in wastewater from Binnan and Hekou oil production plant and pretreatment should be done before integrated utilization. Based on suggestions from published papers on wastewater utilization and local requirement, it can be used for water flooding, space heating, bathing, hothouse and aquaculture, which can mitigate environmental pollution and improve energy structure, showing favorable social and economic benefits. When using the wastewater, its corrosion and scaling tendency must be considered and choose proper pretreatment and pipeline.