滑溜水减阻剂的绿色配体-Fenton降黏试验

Experiment on Reducing Viscosity of Drug Reduction Agents in Slickwater Using Environment-friendly Ligand-Fenton Method

滑溜水减阻剂EM50聚合物给压裂返排液处理带来一定难度。本文采用绿色螯合剂亚氨基二琥珀酸四钠(IDS)配体-Fenton法对减阻剂EM50进行氧化降黏处理。在单因素试验基础上,采用响应面法(RSM)研究影响降黏效果的3个主要因子n(IDS)∶n(Fe(Ⅱ))、Fe(Ⅱ)加量、H2O2加量的最佳水平及其交互作用。结果表明,在pH中性条件下,影响氧化降黏的主次因素依次为:n(IDSTA)∶n(Fe(Ⅱ))、Fe(Ⅱ)加量、H2O2加量;3个因素中,n(IDSTA)∶n(Fe(Ⅱ))与Fe(Ⅱ)加量两个因素的交互作用显著;根据模型预测最优反应条件为:n(IDS):n(Fe(II))=1.4,c(Fe(II))=0.3mmol/L,φ(H2O2)=0.5%。在最优反应条件下质量分数0.1%的EM50溶液的平均降黏率为84.01%,与预测值相对偏差2.62%,说明建立的模型切实可行。降黏后进行混凝处理,压裂返排液SS、COD去除率分别为94.9%、89.2%。

EM50 polymer used in slickwater as drag reduction agents(DRA)makes the treatment of the fracturing flowback fluid more difficult. In this paper,Ligand-Fenton composed of environment-friendly chelating agent tetrasodium iminodisuccinate(IDS)and Fenton was used to reduce viscosity of EM50 solution. On the basis of single-factor design,response surface methodology(RSM)was used to research the best level and mutual effect of n(IDS):n(Fe(Ⅱ)),Fe(Ⅱ)and H2O2 dosage affected on viscosity-reducing rate. The results showed that under neutral pH,the order of three influencing factors on the viscosity-reducing rate was n(IDS)∶n(Fe(Ⅱ))>Fe(Ⅱ)dosage>H2O2 dosage. Among these factors,Interaction between n(IDS)∶n(Fe(Ⅱ)),Fe(Ⅱ)had a signifigant impact on the oxidation efficiency. the predicted optimal conditions was obtained as follows:n(IDS)∶n(Fe(Ⅱ)=1.4,c(Fe(Ⅱ))=0.3 mmol/L and φ(H2O2)=0.5%. Under this conditions,the average viscosity-reducing rate of the EM50 solution with mass fraction of 0.1% was 84.01%,which is compared with resulting in a final response,the relative deviation to the predicted value was 2.62%,indicating that the model was reliable and accurate. When being treated using chemical coagulation after viscosity reducing,the removal rates of SS and COD in fracturing fluid recovery were 94.9% and 89.2%,respectively.