中和-氧化-混凝法联合处理油田酸化废液

Treatment of oilfield waste acidizing fluid by united process with neutralization-oxidation-coagulation

针对油田酸化废液成分复杂、处理难度大的问题,在对酸化废液主要污染物进行成分分析的基础上,通过对p H调节工艺、总铁及悬浮物等污染物去除工艺的研究,形成了中和-氧化-混凝-过滤的处理技术。重点研究了药剂种类、投加量、处理时间等因素对酸化废液处理效果的影响,并对工艺参数进行了优化:Na OH与Ca O质量比为3∶1,c(H2O2)=4 000 mg·L^(-1),氧化时间为20 min,c(PAC)=800 mg·L^(-1),c(PAM)=10 mg·L^(-1)。研究结果表明,酸化废液经最佳工艺处理后可达到回注水水质标准:ρ(悬浮物)<10 mg·L^(-1)、ρ(油)<30 mg·L^(-1)、p H值为6~9、F(腐蚀速率)<0.076 mm·a-1。为酸化废液回注处理工艺、装置的设计及现场实施提供了理论依据与指导。

In view of the problem that the composition of waste acidizing fluid is complicated and this material is difficult to handle,neutralization-oxidation-coagulation-filtration processing technique was developed by evaluating the p H regulation process and the removal of total iron,suspended matter,and other contaminants by analyzing the main pollution components in the waste acidizing fluid. The objective of this work was to investigate the effects of the process conditions（ chemical type,chemical dosage,and processing time） on the removal of pollutants. The optimal process parameters were as follows： mass ratio of Na OH to Ca O of 3 ∶ 1,c（ H2O2） of4 000 mg·L^-1,oxidation time of 20 min,c（ PAC） of 800 mg·L^-1,and c（ PAM） of 10 mg·L^-1. Based on this treatment,the waste acidizing fluid in an oilfield could meet the standards for reinjection（ SS 10 mg·L^-1,oil content 30 mg·L^-1,pH of 6 to 9,corrosion rate 0. 076 mm·a- 1）. Furthermore,this study provides a basis of theoretical guidance for the reinjection requirements and experimental basis for the design and implementation of disposal systems for waste acidizing fluid treatment devices.