延长油田胍胶压裂返排液循环利用技术研究

Recycling technology research of guar gum fracturing flow-back fluid in Yanchang Oilfiled

延长油田油井压裂作业产生的胍胶压裂返排液“四高”(总铁、黏度、悬浮物、细菌)。采用“水质调节-强化絮凝-O 3催化氧化”三步法工艺进行处理后回用。研究表明,在强化絮凝的基础上,通过投加固体催化剂进行臭氧催化氧化反应,返排液黏度显著降低,水质处理效果优良。该工艺最佳参数:pH值为9.0,絮凝剂IF-A投加800 mg/L,助凝剂FA-B投加1.5 mg/L,在A系列固体催化剂与压裂返排液接触环境中通入臭氧30 min。处理后的返排液,总铁浓度可降至1.0 mg/L以下,悬浮物浓度降至2.0 mg/L以下,黏度低于1.10 mPa·s。用三步法处理后液回配滑溜水压裂液的各项指标与用饮用水配制的滑溜水压裂液性能接近,均能满足地方标准《压裂液用滑溜水体系》的要求,符合现场滑溜水压裂液配制用水的要求,并应用于指导页岩气压裂返排液的处理及回用。

Yangchang Oilfiled fracturing operation,the rubber fracturing backflow liquid has the“four highs”(total iron,viscosity,suspended solids,bacteria).The fracturing and returning liquid is treated by the“water quality adjustment-enhanced flocculation-O 3 catalytic oxidation”process.The result showed that on the basis of enhanced flocculation,the process is carried out by adding a solid catalyst to carry out ozone catalytic oxidation reaction,and the viscosity of the return liquid is remarkably lowered,and the water treatment effect is excellent.The best parameters of the process were determined:pH value was 9.0,flocculant IF-A was added 800 mg/L,coagulant FA-B was added 1.5 mg/L,in series A solid catalyst and fracturing backflow liquid ozone was introduced into the environment for 30 min.After the treatment,the total iron concentration can be reduced to less than 1.0 mg/L,the suspended solid concentration is less than 2.0 mg/L,and the viscosity is reduced to 1.10 mPa·s or less.After testing,the performance of the treated slick water fracturing fluid is similar to that of the slick water fracturing fluid prepared with tap water,which meets the standard of the slick water system for fracturing fluid and meets the slick water fracturing.The process was applied to guide the treatment of shale gas fracturing backflow liquid.