XSC-700树脂对压裂返排液中硼的吸附研究

Adsorption of boron in fracturing flow-back fluid by XSC-700 resin

硼交联剂在压裂液中有着重要的作用。经处理后的压裂返排液再次配制压裂液时,残留的硼交联剂含量较高会影响所配压裂液的性能。文章选用XSC-700硼特效树脂对返排液中的残留硼交联剂进行吸附去除,以硼去除率为考察指标,采用单因素实验法探究了初始硼质量浓度、树脂用量、温度、pH值、时间、转速等对吸附性能的影响,分析了Ca^2+,Mg^2+,SO4^2-,CO3^2-等二价离子与硼在树脂上的竞争吸附。结果表明:pH值为9、水中树脂加量2.5%、转速200r/min,室温下吸附1h时,返排液中的硼质量浓度由47.15mg/L降至3.67mg/L,去除率可达92.22%,满足重新配液的要求;返排液中共存的Ca^2+,Mg^2+,SO4^2-,CO3^2-等二价离子对XSC-700树脂吸附硼的影响较小,XSC-700树脂对硼具有极好的选择吸附性。

Boron crosslinking agent plays an important role in fracturing fluid.When the fracturing flow-back fluid is recomposed after effective treatment process,the high content of residual boron crosslinking agent will affect the property of the fracturing fluid.In this work,XSC-700 boron specific resin was selected to remove residual boron crosslinking agent in the fracturing flow-back fluid.The index was removal rate of boron,and single-factor method was adopted to evaluate the influence of initial boron concentration,resin dosage,temperature,pH,time and rotational speed.Moreover,the competitive adsorption between Ca^2+,Mg^2+,SO4^2-,CO3^2-and boron on the resin was also investigated.The results show that the removal rate is 92.22%with an obvious reduction of boron mass fraction from 47.15 mg/L to 3.67 mg/L meeting the requirement of flow-back fluid reutilization under the optimum conditions:pH is 9,resin dosage in water is 2.5%,rotational speed is 200 r/min,and adsorption time is 1 h at room temperature.The coexistence of Ca^2+,Mg^2+,SO4^2-,CO3^2-in the flow-back fluid had little effect on the adsorption activity of boron XSC-700 resin.XSC-700 resin has excellent selective adsorption of boron.