DTPA对BaSO₄垢清除作用的影响因素研究

Study on Influence Factors of Clearance Function of DTPA on BaSO₄ Scale

于洪江 肖志海

YU Hongjiang，XIAO Zhihai

以二乙基三胺五乙酸（DTPA）为主剂，考察了不同转化剂和表面活性剂对DTPA溶BaSO4垢率的影响。实验结果表明，随DTPA浓度增大，其溶解BaSO4垢的能力增强。分子含共轭双键的一类物质能明显增加DTPA的溶垢速率，其中与肉桂酸的协同效应最佳；适量的非离子表面活性剂能增强除垢效果。在25℃、pH值为12、反应时间10 h 的条件下，通过正交实验得到DTPA、肉桂酸和脂肪醇聚氧乙烯醚（PPJ）的最佳浓度分别为0.075、0.075和0.02 mol/L，在此加量下测得BaSO4除垢率为89.01%。用油田采出水配制该配比的溶液进行岩心溶垢实验，岩心渗透率恢复率达到94.67%。图4 表2 参12

Adopting diethylenetriaminepentaacetic acid（DTPA）as main agent，the effects of different conversion and surfactant agent on the dissolution rate of BaSO4 scale by DTPA were investigated. The experiment results showed that descaling effect would enhance when the concentration of DTPA increased. The compounds whose molecular contained conjugated double bond could significantly increase the dissolution rate of BaSO4 scale，especially with the synergistic effect of cinnamic acid. In addition， appropriate amount of nonionic surfactant could enhance the descaling effect. Through orthogonal test，the descaling rate could reach 89.01% when the optimum concentration of DTPA，cinnamic acid and alcohol ethoxylate（PPJ）was 0.075，0.075 and 0.02 mol/L，under the condition of 25℃，12 pH value and 10 hrs reaction time. And the core permeability recovery rate could reach 94.67% by adopting oilfield produced water as the solution at the present ratio in core scale dissolution experiment.