Test And Process Design Of Ceramic Plate Membrane Combined With Active Coke Treatment Of Oilfield Produced Water

At the present stage,most of the oil fields have entered the middle and late period of mining,the water content in the extracted oil is up to 70%?80%.Due to the difference between the mining strata and the oil production process,the difference between the produced water at each stage is very large and the ingredient is very complex,resulting in that it can not be directly discharged or reinjected into the stratum.Therefore,the remaining produced water should be treated to the standard.According to the latest Liaoning province comprehensive wastewater discharge standard issued by the country(DB21 1627-2008),the higher requirements for the drainage quality of produced oilfield water have been put forward,It is necessary to update the treatment process so that the treated sewage quality of the produced oilfield water can reach the standard.Through comparative analysis of various sewage treatment methods,a pilot test of active coke combined with biological method was carried out for oilfield produced water from a certain Liaohe oil field.The pilot test adopts pre adsorption,anaerobic hydrolysis acidification,biological aerobic oxidation,adsorption and separation process flow.The COD of raw water is between 358.7mg/L and 589.2mg/L.After pre-adsorption,the COD is stable to 147.06mg/L.The COD value of the effluent at biological stage is 68mg/L,and the biological effluent fails to achieve the expected effect.After adding the adsorption treatment,the COD of the effluent is 36.12mg/L-48.88mg/L,and the effluent quality reaches the standard.In view of the poor effect of the biological link treatment and the failure to meet the emission standards,it is necessary to improve the treatment method.A beaker experiment was carried out on the optimized treatment of the effluent from the pilot anaerobic link with the method of active coke and ceramic plate membrane.It was found that the COD decreased significantly in the wastewater,it was found that the COD in the sewage was significantly decreased,when the hydraulic retention time is 4h and the active coke dosage is 0.8kg/t,the treatment results can meet the discharge standard.The active coke used in the test is similar to the activated carbon,and it also overcomes the defects of low mechanical strength and high price of activated carbon.The ceramic plate film has high mechanical strength,good pollution resistance and good interception ability,which can effectively separate water and active coke.This paper presents an optimization process for the treatment of water production in oil field with active coke and ceramic plate membrane as the core,the core process design process is pre adsorption,anaerobic hydrolysis acidification,post adsorption and plate membrane separation.The main structure of the design process includes mechanical agitation tank,radial flow sedimentation tank,hydrolytic acidification tank and flat membrane tank.The design parameters include flow volume,size,residence time and so on.The experimental study has proved that active coke combined with ceramic plate membrane is feasible to treat oil produced water in oil field,treated oilfields water quality meets the requirements of the comprehensive sewage discharge standard of Liaoning Province,and the process design of the sewage station is carried out according to the actual situation in the fields.This paper provides new ideas for the treatment of oilfield produced water,and provides design basis for similar sewage treatment.