硼含量对压裂液特性的影响

Influence of Boron content on characteristics of fracturing fluid

目前压裂是油气田增产增注的重要措施,作业后产生的返排液已成为油气田环保重要控制污染物之一,压裂返排液处理后再利用已成为污水资源化的重要发展方向。本文针对蒸馏水、自来水、长六模拟水和处理后返排液四种不同对象展开研究,分析四种水溶剂中不同浓度梯度的硼含量下对压裂液基液黏度、耐温性及抗剪切性能的影响。研究表明:硼在蒸馏水中为1 mg/L时对压裂液基液黏度、耐温及抗温抗剪切性无影响;硼在自来水中为2 mg/L时对压裂液基液黏度、耐温及抗温抗剪切性无影响,符合压裂液性能指标;硼在长六模拟水中为12 mg/L时及在处理后返排液中外加20 mg/L对基液黏度无影响,但不加硼时,两种溶剂对应压裂液耐温性为60℃,抗温抗剪切性只能保持2 min,性能极差。

At present, fracturing is an important measure to increase production and increase injection of oil and gas fields. The return fluid generated after operation has become one of the important control pollutants for the environmental protection of oil and gas fields, re-use of fracturing fluid backwaters has become an important development direction of wastewater resource utilization. In this paper, four different objects of distilled water, tap water, No.6 simulated water and treated backflow liquid were studied. The viscosity, temperature resistance and shear resistance of the fracturing fluid base fluids were analyzed under Boron concentrations of four water solvents with different concentration gradients.The results show that Boron has no effect on the viscosity, temperature resistance and shear resistance of the fluid at 1 mg/L in distilled water. When the concentration of Boron in tap water is 2 mg/L, it has no effect on the viscosity,temperature resistance and shear resistance of the fracturing fluid,which accords with the performance index of fracturing fluid. When Boron is 12 mg/L in No.6 simulated water and 20 mg/L in liquid medium after treatment, the viscosity of base fluid has no effect on the viscosity of base fluid. However, when Boron is not added, the temperature tolerance of the two solvents corresponding to the fracturing fluid is 60 ℃. Anti-temperature shear resistance can only maintain 2 min, poor performance.