酸化返排液无害化处理技术研究

A study on acidizing flowback water treatment

关键词:  酸化返排液  无害化处理  水质指标 

Key words:  acidizing flowback water  innocent treatment  water quality parameter

摘要:

针对现有酸化返排液处理工艺不完善、水质不达标,影响联合站正常运行的问题,通过对多口酸化井返排液的分析表明,酸化返排液具有pH值低、总铁离子浓度高、腐蚀速率高等特点,建立了“沉降-中和-氧化-絮凝”组合处理工艺,优化确定了工艺参数,实现处理后水pH值为6.7～7.5,总铁离子质量浓度小于5 mg/L,腐蚀速率小于0.076 mm/a,原油质量浓度低于20 mg/L,悬浮物质量浓度低于20 mg/L,达到联合站进水要求。 

Abstract:

Since current acidizing flowback water treatment system was not well designed, the effluent could not meet the requirements and influence the operation of the joint station. In this study, based on analysis of multiple water samples, it was concluded that the acidizing flowback water was always associated with low pH, high total iron concentration, and high corrosion rate. Furthermore, combined process as “sedimentation-neutralizaiton-oxidation-coagulation/flocculation” was developed and the operation parameters were optimized to improve the treatment. The results showed that the treated water could satisfy the requirements of the joint station, with the situation that pH ranges from 6.7-7.5, total iron concentration is below 5 mg/L, corrosion rate is less than 0.076 mm/a,oil content is below 20 mg/L, and total suspended solid content is less than 20 mg/L. This study provided technical reference for acidizing flowback water treatment.