Abstract: TAs Changqing Oilfield’s exploration and development is unfolded on a larger scale, the environmental issue becomes a focus of attention because water consumption and waste water increase year by year. Based on the design of functional module, the fracturing fluid recovery and recycling device is developed for oil and gas fields. The device is composed of a series of functional modules, such as oil and sand removal, coagulation - settlement - filtration - disinfection, sludge treatment and water quality testing. Each functional module can be combined with one another according to actual need, suitable for recovering and handling fracturing fluid under various conditions. The post-treatment water turbidity is low with the removal rates of suspended solids and high valence ion exceeding 90 percent and 70 percent separately. Suspended solids in the water is less than 10mg/L, petroleum less than 10mg/L, Ca²⁺ less than 100mg/L, Mg²⁺ less than 100mg/L, total ferrous content less than 10mg/L and pH 6.5 to 7.5, meeting the recycling requirements. This device has been used for more than 100 horizontal wells on blocks of Longdong, Ansai, Sulige and Jingbian of Changqing Oilfield. The recovery and recycling rate of fracturing fluid flowback exceeds 80 percent, saving more than 100,000 cubic meters of water and significantly lowering operational cost for production. The device has effectively solved the environmental issue in the oil areas.

Key words: fracturing fluid, recovery, recycling, waste water treatment, functional module

摘要： 随着长庆油田勘探开发规模的扩大,压裂作业用水量与废水产生量逐年增加,由此带来的环境问题日益受到关注。以功能模块化为设计思路,研制了油气田压裂液回收再利用装置,该装置主要由除油除砂、混凝—沉淀—过滤—杀菌、污泥处理、水质检测等功能模块组成,各功能模块可根据实际需要进行组合,适用多种条件下压裂液的回收处理。处理后水浊度较低,悬浮物去除率大于90%,高价离子去除率大于70%,水中悬浮物小于10mg/L,石油类小于10mg/L,Ca²⁺含量小于100mg/L,Mg²⁺含量小于100mg/L,总铁含量小于10mg/L,pH值为6.5~7.5,满足再利用的要求。该装置已在长庆油田陇东、安塞、苏里格、靖边等重点油气区100余口水平井实现规模应用,压裂返排液回收再利用率达80%以上,节水量达10余万立方米,生产作业成本大幅降低,有效解决了油区安全环保问题。

关键词: 压裂液, 回收, 再利用, 废液处理, 功能模块