一种油田采出水用复合阻垢缓蚀剂的研究

A Composite Scale and Corrosion Inhibitor for Oilfield Produced Water

目的找到一种可以应用于油田采出水处理的新型绿色阻垢缓蚀剂。方法以N80钢为研究对象,在油田采出水模拟水质中分别采用静态阻垢实验、静态挂片实验和极化曲线、电化学阻抗法对阻垢缓蚀剂的阻垢性能和缓蚀性能进行研究。结果通过正交实验确定了聚环氧琥珀酸、氨基三亚甲基磷酸和水解聚马来酸酐的比例,确定了阻垢缓蚀剂的配方,确定阻垢缓蚀剂在油田采出水中的最优加量为20 mg/L,该阻垢缓蚀剂可以应用于较高钙含量、p H值在6.0~8.0之间的油田采出水的处理,其阻垢率可以达到90%以上。通过极化曲线和电化学阻抗法得到,该阻垢缓蚀剂属于以抑制阴极为主的混合型缓蚀剂,在油田采出水中的添加量为20 mg/L时,缓蚀率可以达到82%以上,使腐蚀速率大幅降低,满足行业标准的要求。结论该复合型阻垢缓蚀剂制备简单,阻垢缓蚀性能良好。

The work aims to explore a new type environment friendly composite scale and corrosion inhibitor for oilfield produced water treatment. By taking advantage of static scale inhibition test, static weight-loss method, polarization curve and electrochemical impedance spectroscopy, the scale and corrosion inhibition on N80 carbon steel was investigated in simulated quality of oilfield produced water. The propotion of polyepoxysuccinic acid, ATMP and hydrolytic polymaleic anhydride were determined by virtue of orthogonal experiment. In addition, the optimum formula of the scale and corrosion inhibitor was determined and its added amount in oilfield produced water was tested to be 20 mg/L. The scale and corrosion inhibitor could be used in treating oilfield produced water of high content of calcium and p H value within 6.0~8.0. Its scale inhibiting ratio could be up to more than 90%. The polarization curve and electrochemical impedance spectroscopy showed that the scale and corrosion inhibitor was a mixed-type inhibitor mainly restraining the cathodic process of metal. The corrosion-inhibiting rate could be up to more than 82% when 20 mg/L of the inhibitor was added to the oilfield produced water, reducing the corrosion rate signif-icantly and meeting requirements of industry standards. The scale and corrosion inhibitor was prepared easily and provided with excellent scale and corrosion inhibition performance.