Treatment Method For Oil Produced Water In Liaohe Oilfield

The purpose of the paper is solving the problem of oil produced water of Liaohe oilfield. The research way of this study aimed at the difference character of the produced water of Liaohe oilfield. For the ordinary produced water, analysis it's current treatment equipment, use the current equipment as far as possible, add new facilities behind the current equipment to decompose the organic matter in the water, make the water from the whole facilities can reach the standard of our country. For viscous crude water, the first aim is remove the oil and SS from the water. We have researched efficiently chemical drugs to treatment the water, and consult the treatment way of ordinary produced water, development a whole system of technology to treatment the viscous crude water to reach the standard.In order to solve the problem that remove the oil and SS from viscous crude water, we study two kinds of chemical drugs to treatment the water, and their names are TJ-1 and P-3. For the ordinary produced water, the dose of TJ-1 is 25~50mg/L, the dose of P-3 is 0.5~1.0mg/L; For viscous crude water, the dose of TJ-1 is 75~100mg/L, the dose of P-3 is 2 - 3mg/L; The concentration of oil will reduce to 10mg/L.According to the analysis of treatment result, expenses, energy consumption and cover area of every kind of technology, and also according to the investigation to water treatment technology of Liaohe petrochemical company, we decide that the produced water of Liaohe oilfield will be treated with physics-biological treatment methods. 1 . The current treatment way of ordinary produced water can reduce the concentration of oil and SS to meet the request of biological treatment, according to the principle of reduce the cost, we add anaerobic and aerobic treatment behind the current treatment equipment. The equipment used in experiment is list below:The water from current treatment equipment - anaerobic treatment - aerobic treatment - sediment can - dischargeThe test of Xingyilian show: After this kind of treatment, oil, SS, CODcr and BOD5 in the water is reduced a lot. The concentration of oil reduced to 10mg/L, the average ratio of reduced is 81%, the average ratio of reduced of SS is 76.2%, BOD5 is 90.5%, COD is 82.7%. Oil, SS and BOD5 can reach the standard of first degree, and COD can reach the standard of second degree.2. For viscous crude water, concentration of oil from its current treatment equipment is about 100mg/L, the maximum concentration is 600mg/L. It can't be treated by biological methods. So thinking of our result of treatment drugs experiment, we design a system of new technology to treat viscous crude water, as below:TJ-1 P-3Water - balanced can - reaction can - CPI - reaction can - floating can - anaerobic treatment - aerobic treatment - sediment can - dischargeAccording to our experiment, we concluded: TJ-1 and P-3 play key role in the treatment, the average ratio of reduced of oil rise 16%. Anaerobic treatment can enhance the ability of aerobic treatment, BOD5/CODcr rise form 0.2 to 0.3. After treatment, CODcr is blow 100mg/L. So through physics treatment, anaerobic and aerobic treatment, the produced water of Liaohe oilfield could reach the discharge standard of China.