Study on Determination of Boron Content in Fracturing Flow-back Fluid by Titration

Abstract

The accurate determination of the residual boron content is of great significance to reutilization and the control of treatment cost of the treated fracturing flow-back fluid in the oil field. This work mainly investigated the influence of coexisting ions on measurement of boron content in oil field fracturing flow-back fluid, with the mixed solution of bromocresol green-methyl red-phenolphthalein as the indicator, by using mannitol acid-base neutralization titration. The results show that the optimum range of the method is 50 ~ 300 mg/L, and the content of Fe3+, Ca2+, Mg2+, SO4 2-, suspended matter and oil in the fracturing flow-back fluid have less effect on the accuracy of the determination results. The relative standard deviation is 0.49%, and the recovery rate is 99.08% ~ 100.70%. The precision and accuracy of this method can satisfy the quality requirements of the analysis.