合水油田注水管网缓蚀剂XD的开发优化与应用研究

Research on development and application of corrosion inhibitor XD for water injection pipe networks in Heshui Oilfield

关键词:  注水管网  聚类分析  腐蚀成因  配方优化 

Key words:  water injection pipe networks  cluster analysis  corrosion reason  formula optimization

摘要:

为了解决合水油田注水管网严重腐蚀这一问题,首先利用K-均值聚类分析对在役586条注水管线进行研究,找出最具代表性的庄一注、庄二注、庄三注作为新型复配缓蚀剂XD的试验对象,然后通过对试片腐蚀形貌以及腐蚀产物组成、含量的检测来确定注水管网的腐蚀成因。最后,针对此问题合成了一种多位点吸附型咪唑啉季铵盐MIQAS, 以MIQAS为缓蚀剂,聚环氧琥珀酸钠(PEAS)为阻垢剂,1,2苯并异噻唑啉-3-酮(BIT)为杀菌剂进行复配, 并借助单因素和多指标正交试验设计对MIQAS、PESA和BIT含量进行优化。结果 表明,溶解氧、侵蚀性CO₂、Cl-引起的吸氧腐蚀、CO₂腐蚀和点蚀是导致注水管网腐蚀的主要原因,Ca²⁺、细菌造成的结垢腐蚀和细菌腐蚀对其也有一定影响。当该复配缓蚀剂ρ(MIQAS)∶ρ(PESA)∶ρ(BIT)=120 mg/L∶65 mg/L∶50 mg/L时,XD对庄一注、庄二注和庄三注的缓蚀率分别高达98.24%、98.63%、99.17%,取得了良好的防腐效果。 

Abstract:

In order to solve the severe corrosion of water injection pipe networks in Heshui Oilfield, 586 water injection pipelines in service were studied using K-means clustering analysis. Zhuangyizhu, Zhuangerzhu and Zhuangsanzhu were selected as representative experimental objects of new compound inhibitor XD. Micro-morphology of steel sheet, composition and content of corrosion products were determined and analyzed to find out the corrosion reason. A kind of multi-adsorbed-sites imidazoline quaternary ammonium salt MIQAS was synthesized aiming at above problems. Then, single factor and multi-target orthogonal design experiments were employed to optimize MIQAS, PESA and BIT content. The results show that the main reasons of corrosion including oxygen absorption, acid and pitting induced by dissolved oxygen, erosive carbon dioxide and chloride. The fouling corrosion and bacterial corrosion caused by calciumion and bacteria were also damaged water injection pipe networks. Under the condition of ρ(MIQAS)∶ρ(PESA)∶ρ(BIT)=120 mg/L∶65 mg/L∶50 mg/L, the inhibition efficiency of average corrosion for Zhuangyizhu, Zhuangerzhu and Zhuangsanzhu achieved 98.24%, 98.63% and 99.17%, respectively. The new compound inhibitor XD has good anti-corrosion performance for water injection pipe networks.