耐酸性气体腐蚀水泥添加剂DC206的研制及性能评价  

Development and Its Performance Evaluation of Cement Additive DC206 to Acid Gas Corrosion

作　　者：周仕明[1] 谭春勤[1] 

机构地区：[1]中国石化石油工程技术研究院,北京100101

出　　处：《石油钻探技术》2011年第1期25-28,共4页Petroleum Drilling Techniques

基　　金：国家高技术研究发展计划("863"计划)项目"高温高压高含硫气井新型防气窜防腐水泥浆体系研究"(编号:2006AA06Z209)部分研究内容

摘　　要：为了满足酸性油气田勘探开发的需要,在系统分析CO2和H2S在湿环境下腐蚀水泥石机理的基础上,开发了DC206防腐蚀剂。室内性能评价试验表明,在常规水泥浆中加入DC206,经CO2或H2S腐蚀21 d后,水泥石的强度损失和渗透率增高趋势得到有效抑制,与基本水泥相比有较大改善。通过分析腐蚀产物和水泥石微观结构可知,DC206的主要作用机理是:DC206首先消耗掉水泥石中的Ca(OH)2,降低了水泥石碱度,使水泥石在CO2和H2S环境下的腐蚀反应速度大大降低;在CO2腐蚀环境下DC206能够有利于腐蚀产物CaCO3转向方解石结晶,而方解石的晶体排列紧密,可提高水泥石强度,降低其渗透率;在H2S腐蚀环境下,由于DC206消耗掉水泥水化产生的Ca(OH)2,使H2S不能直接与Ca(OH)2反应生成具有膨胀作用的二水石膏,从而能减少水泥石中的裂纹,降低渗透率。In order to meet the requirement of exploration and development in acid oil and gas fields, the DC206 inhibitor was developed based on systematical analysis of corrosive mechanism of CO2 and H2S to cement under wet environment. The indoor experiment showed that cement mixed with DC206 can effectively control the strengthen loss and the increase of permeability after CO2 or H2 S corrosion for 21 days. By analyzing the corrosive products and microstructure of set cement, the main mechanism of DC206 is believed to be the reaction with Ca（OH）2 of set cement to reduce the alkalinity. The corrosion rate is reduced significantly under CO2 or H2 S environment. Under CO2 environment,DC206 can help the corrosion product CaCOa to generate calcite crystal, which raises the strength of cement and reduces the permeability by tight crystal arrangement of calcite. Under He S environment, because DC206 consumes Ca（OH）2 which is produced from cement hydration,it prevents the generation of expansive CaSO4 · 2H2 O which reduces the crack and lowers the permeability of set cement.

关 键 词：二氧化碳腐蚀 硫化氢腐蚀 防腐剂 腐蚀控制 水泥石 实验室试验 

分 类 号：TE256.6[石油与天然气工程—油气井工程]