一种新型高温酸化缓蚀剂的制备及性能评价

目的改善缓蚀剂在高温酸液中的缓蚀性能,满足油田高温井酸化施工的要求。方法在合成一种新型吡啶季铵盐的基础上,添加炔醇、碘化钾等助剂进行复配,得到一种新型高温酸化缓蚀剂HTCI-1。使用HK-1高温高压动态腐蚀仪对其缓蚀性能进行测试,通过电化学测试、SEM、EDS等实验对其缓蚀机理进行分析。结果该酸化缓蚀剂在160℃、16 MPa、20%HCl或者土酸(12%HCl+3%HF)、质量分数3.0%的条件下,使N80试片的腐蚀速率分别为24.53 g/(m~2·h)和23.72 g/(m~2·h),达到了SY/T 5405—1996中的一级指标。结论在高温酸液中,N80钢片腐蚀速率降低,主要是由于缓蚀剂分子吸附到碳钢表面形成了一层致密的疏水性吸附膜,从而降低了侵蚀性离子与钢铁表面接触的几率,腐蚀电极反应过程受到抑制,达到了高温条件下防护金属的目的。

Preparation and Performance Evaluation of a New High Temperature Acidizing Corrosion Inhibitor

The work aims to improve corrosion inhibition of corrosion inhibitor in high temperature acid liquor and meet requirement of high temperature well acidizing treatment. A new high temperature corrosion inhibitor HTCI-1 was obtained by compounding such additives as potassium iodide and potassium iodide in a newly synthesized pyridine quaternary ammonium salt. The corrosion inhibition was also tested by using high temperature and high pressure dynamic corrosion instrument HK-1, the corrosion mechanism was analyzed by performing electrochemical test, SEM, EDS and other tests. Tests showed that corro-sion rate of N80 test block reached 24.53 g/(m2·h) and 23.72 g/(m2·h) provided with 160℃, 16 MPa, 20%HCl or mud acid (12%HCl+3%HF) and 3.0% mass concentration, meeting the first grade indicator in SY/T 5405—1996. Main cause of decrease in corrosion rate of the N80 steel sheet in high temperature acid liquor is that a dense layer of hydrophobic adsorption film forms on the surface of carbon steel as corrosion inhibitor molecules are absorbed onto carbon steel, which reduces the possibility of erosive ions contacting with steel surface, inhibits corrosion electrode reaction process and achieves the purpose of protecting metal at high temperature.