油田管道腐蚀极端严重，添加缓蚀剂，是经济高效的防腐蚀方案之一。本文以二乙烯三胺、月桂酸和对苯二甲酰氯为原料，成功设计合成了单咪唑啉IM和以苯环为分子中心的双咪唑啉型缓蚀剂BIM。通过正交试验，优化了合成工艺。通过静态挂片对两种缓蚀剂在酸液中的缓蚀性能进行了评价，研究了其在金属上的吸附行为。分析了造成马岭北三区油田管道腐蚀的因素，通过静态挂片和极化曲线对BIM在油田水中的缓蚀效果和机理进行了研究。得到主要研究结果如下：

(1) 缓蚀剂合成的优化工艺条件为：二乙烯三胺与月桂酸按1.1:1的摩尔比投料，二甲苯作携水剂，微波条件下150℃酰化2 h后，180℃环化3 h得单咪唑啉缓蚀剂IM。单咪唑啉与对苯二甲酰氯以摩尔比2.2:1投料，二氯甲烷为溶剂，K₂CO₃为缚酸剂，恒温水浴下50℃反应9 h，得双咪唑啉缓蚀剂BIM；

(2) 对于L245N金属试片，在1 mol/L的盐酸溶液中，IM和BIM缓蚀剂均可达到98%左右的缓蚀率，其中BIM缓蚀剂的用量仅需0.5 mg/L以上就可达到高缓蚀率。BIM的缓蚀效果随腐蚀时间的增加有所下降，且在酸性条件下缓蚀效果更佳；

(3) 研究表明，L245N、20、N80、J55、80S、P110六种型号的金属在马岭北三区油田水中基本为中等腐蚀，而HCO₃^-，微生物，尤其是硫酸盐还原菌，高矿化度，溶解氧，Cl^-以及Ca²⁺，Ba²⁺和SO₄^2-等成垢离子是引起马岭北三区管道腐蚀的主要因素。以清水为腐蚀介质评价了BIM对L245N试片的缓蚀效果，当缓蚀剂浓度为5 mg/L时，缓蚀率高达74.79%；在清水和木H5-1中，BIM对六种金属均有良好的缓蚀效果；

(4) 对缓蚀剂吸附过程进行模拟发现，IM和BIM均符合Langmiur等温吸附模型，吸附吉布斯函数变化分别为-53.04和-54.95 kJ/mol，表明IM和BIM的吸附过程均属于化学吸附；电极化曲线表明，BIM属于以抑制阳极反应为主的混合型缓蚀剂。

The corrosion of oil field pipeline is extremely serious. Adding corrosion inhibitor is one of the economic and efficient anti-corrosion schemes. In this paper, diethylene triamine, lauric acid, and terephthaloyl chloride were used to synthesize a monoimidazoline intermediate IM and a bisimidazoline corrosion inhibitor BIM with a benzene ring as the molecular center in three steps. The product was characterized by FTIR, and the synthesis process was optimized by orthogonal test. The performance of the two inhibitors in acid solution was evaluated by static hanging plate, and their adsorption behavior on metal was studied. The factors that cause the pipeline corrosion in the third area of Maling oilfield are studied. The inhibition effect and mechanism of bisimidazoline inhibitor in oilfield water are studied by static hanging plate and polarization curve. The main results are as follows:

(1) The optimum process conditions for the synthesis of corrosion inhibitor are as follows: diethylene triamine and lauric acid molar ratio of 1.1:1, xylene as water-carrying agent, acylation at 150℃ for 2 h and cyclization at 180℃ for 3 h under microwave to obtain monoimidazoline inhibitor IM. BIM was prepared by the reaction of monoimidazoline and p-benzoyl chloride in a molar ratio of 2.2:1, dichloromethane as solvent, K₂CO₃ as acid binding agent and 50℃ in a constant temperature water bath for 9 h;

(2) For L245N metal test piece, in 1 mol/L hydrochloric acid solution, IM and BIM inhibitor can achieve about 98% inhibition rate, but the amount of BIM inhibitor only needs more than 0.5 mg/L to achieve high inhibition rate, which is far less than IM. The inhibition effect of BIM decreased with the increase of corrosion time, and the inhibition effect was better in acid condition;

(3) The results show that the corrosion of L245N, 20, N80, J55, 80S and P110 in the oilfield water of Maling north area is basically moderate, and HCO₃^-, microorganism, especially sulfate reducing bacteria, high salinity, dissolved oxygen, Cl^-, Ca²⁺, Ba²⁺, SO₄^2- and other scaling ions are the main factors that cause pipeline corrosion in the north of Maling. The inhibition effect of BIM on L245N specimen was evaluated with clear water as the corrosion medium. When the concentration of inhibitor was 5 mg/L, the inhibition rate was 74.79%;  In clear water and wood H5-1, BIM inhibitor has good corrosion inhibition effect on six kinds of metal test pieces;

     (4) It was found that the adsorption process of IM and BIM conformed to Langmuir isotherm adsorption model, and the change of adsorption Gibbs function was -53.04 kJ/mol and -54.95 kJ/mol, respectively, which indicated that the adsorption process of IM and BIM belonged to chemical adsorption; The electric polarization curve shows that BIM inhibitor is a mixed inhibitor mainly for inhibiting anode reaction.