水力压裂技术是非常规油气藏开发过程中最常采用的技术，对稳产增产、保障能源安全具有重要意义。压裂液成分复杂、有机污染物难降解，未经有效处理就返排将对生态环境造成严重污染。现有返排液处理工艺复杂、成本较高，因此研究返排液的就地快速处理回用工艺，有助于节约资源、降低成本，对促进非常规油气藏开采利用具有重要意义。本文以大庆油田采油七厂的返排液为样本，开展了破胶工艺参数优选、返排液絮凝回用效果对比和返排液快速处理工业化中试等工作，返排液指标实测结果满足返排液就地快速处理的需求。现场的返排液粘度值达到8.3 mPa/s，CODcr值达4802 mg/L，SS值达到2975 mg/L，具有高粘度、高CODcr、高SS等特点。在试验的破胶剂中，次氯酸钠的效果最优。通过正交分析，返排液初始pH值对次氯酸钠破胶效果影响最大，破胶剂浓度次之，反应时间的影响最小。最佳工艺条件是浓度取3000 mg/L，反应时间取30 min，初始pH值取7。絮凝处理效果受多种因素影响，1600 mg/L浓度的PAC-30絮凝剂、15 mg/L浓度的PAM阳离子-60助凝剂，搅拌速度200 rpm，反应5 min、沉淀20 min的条件下，絮凝效果较好。优选的快速处理工艺在大庆地区、内蒙古地区和陕西地区取得较好的工程应用效果，处理后的返排液中，SS含量降低于1 mg/L、油含量低于5 mg/L、CODcr含量低于110 mg/L。根据五家企业提供的租金和处理能力，考虑包括产品处理费用、生产成本、年化收益率等影响因素在内的投资决策。根据五家企业提供的租金和处理能力，考虑包括产品价格、生产成本、年化收益率等影响因素在内的投资决策。在年化收益率为10%的前提下，价格在9~10.69 元/m3之间时，选择装置A；在10.70~11.43 元/m3之间时，选择装置B；价格大于11.44 元/m3时，选择装置E。在价格小于8.88 元/m3时，不做该投资。

Hydraulic fracturing technology is commonly used in extraction of unconventional energy, which is of great significance for maintaining production、increasing production and ensuring energy security. The agents added in fluid to improve fracturing effect and the compounds in natural reservoir have the characteristics of complex composition and difficult degradation. Backflow without effective treatment will cause serious pollution. Flowback fluid treatment process is complex and the recovery cost is high. Research on reuse process after rapid treatment in situ is helpful to save resources and reduce costs, which also promote exploitation and utilization of unconventional oil and gas energy.Taking flowback fluid of No.7 Production plant in Daqing Oilfield as example, this research focus on optimization of rubber breaking parameters，flocculation reuse effect and industrial pilot test of rapid treatment. The measured results of flowback fluid index met the needs of rapid local flowback.The viscosity, CODcr and SS of the flowback liquid is 8.3mPa /s, 4802 mg/L and 2975 mg/L，respectively. In the given breaker, sodium hypochlorite has the best effect. Through orthogonal analysis, the initial pH value of liquid has the greatest influence on breaking effect of sodium hypochlorite, followed by the concentration of agent, while the reaction time has the least influence. The optimum process conditions are 3000 mg/L concentration, 30 minutes reaction time and 7 initial pH value. The flocculation effect was affected by many factors. The flocculation effect was better under the condition of 1600 mg/L PAC-30 flocculant and 15 mg/L PAM Cation-60 coagulant, stirring intensity of 200 rpm, reaction time of 5 min and precipitation time of 20 min. The process researched has obtained good engineering application results in Daqing area, Inner Mongolia area and Shaanxi area. In terms of the SS content, the index of the flowback fluid after treatment is limited to 1, while the oil content is less than 5, and the CODcr content is less than 110. Based on the rent and processing capacity offered by the five enterprises, investment decisions including product price, production cost, annualized yield and other influencing factors are considered. Under the premise of 10% annual return rate, when the price is between 9 and 10.69 yuan /m3, choose equipment A; When it is between 10.70 and 11.43 yuan /m3, choose equipment B; When the price is greater than 11.44 yuan /m3, E equipment is selected. When the price is less than 8.88 yuan /m3, do not make the investment.