硅钼酸光度法定量测定钻井液中的聚醚多元醇含量

Quantitative Determination of Polyether Polyol in Drilling Fluid by Silicon Molybdic Acid Spectrophotometry

宋碧涛 陈雪艳 谭 敏 薛 芸 刘子龙 王赪胤

SONG Bi-Tao CHEN Xue-Yan TAN Min XUE Yun LIU Zi-Long WANG Cheng-Yin

基于硅钼酸、氯化钡、聚醚多元醇形成三元络合物的原理，用紫外分光光度法测定钻井液中剩余硅钼酸的吸光度（A），通过A与聚醚多元醇的含量成线性关系来定量聚醚多元醇。具体步骤为：取3.5 mL经过稀释的待测样品，加入稀盐酸调节pH值为2。加入1 mL 300 g/L氯化钡溶液，静置5 min，在9000 r/min转速下离心5 min。加入100.00 μL硅钼酸水溶液，静置30 min，在9000 r/min转速下离心5 min，上清液在210 nm处出现峰值。A与聚醚多元醇质量分数W的线性关系为A=?0.1196W+0.6732，线性相关系数0.996。用该法测得江苏油田梁X15井1450 m钻井液中的聚醚多元醇质量分数为1.01%，相对标准偏差2.0%。

Based on the complex of silicon molybdic acid, barium chloride and polyether polyol, an ultraviolet spectrophotometry was established to determine the absorbance (A) of residual polyether polyol in drilling fluid. The polyether polyol mass fraction (W) was then calculated by the linear relationship between A and W. The optimum determining method was obtained as follows. Hydrochloric acid was added in 3.5 mL diluted sample and the pH value was adjusted to 2. Then 1 mL 300 g/L barium chloride was added, standing for 5 min and centrifuged for 5 min at 9000 r/min. At last, 100.00 μL silicon molybdic acid was added, standing for 30 min and centrifuged for 5 min at 9000 r/min. The supernatant was measured at 210 nm. The linear relationship between A and W was A=?0.1196W+0.6732 and the linear correlation coefficient was 0.996. The drilling fluid of Liang X15 well in Jiangsu oilfield at 1450 m was determined by this method. The mass fraction of polyether polyol was 1.01% and the relative standard deviation was 2.0%.