大庆油田压裂管柱腐蚀规律及缓蚀剂筛选评价

发布时间：2018-06-21 15:11

  本文选题：缓蚀剂 + 大庆油田　； 参考：《东北石油大学》2017年硕士论文

【摘要】：随着石油工业的快速发展,CO_2等酸性气体的腐蚀问题已经成为制约气田快速有效开发的重要问题,针对这一情况,需要对压裂管柱的腐蚀规律进行分析,并在此基础上筛选出适用于压井液的缓蚀剂。本文首先研究了压裂管柱腐蚀失效的原因,发现油管在压井液中长时浸泡后形成了垢下的局部腐蚀。压井液油管表面存在的腐蚀现象是由O_2和CO_2共同腐蚀导致的,而压井液中大量活性氯离子的存在,加速了垢下点蚀的发生,三种腐蚀相互促进,造成了油管的严重腐蚀。并认为压井液在地层高温以及长时间作用下,压井液中的水分逐渐流失,在油管外壁上析出盐分,形成一层垢层,创造了点腐蚀的发生条件,而在油管内壁,压井液中的水分无法流失,所以形成不了垢,因此腐蚀较轻,因此应尽量避免油管长期搁置于井下。之后对不同压井液体系中的腐蚀规律进行了研究,综合比较了N80钢、13Cr不锈钢在三种高比重压井液中的腐蚀速率,可得出其腐蚀性顺序为:KCl压井液NaNO_3压井液甲酸钠压井液。之后针对腐蚀最为严重的KCl压井液-N80钢体系,评价了不同缓蚀剂对N80钢的缓蚀效果,发现硅酸钾和聚丙烯酰胺以1:1复配使用时,缓蚀效果可以达到90%以上。该缓蚀剂配方应用于大庆外围气田现场应用,对各处缓蚀剂加注管线进行了腐蚀检测,检测结果表明属于轻度腐蚀,缓蚀效果良好,在大庆外围气田腐蚀控制中得到了成功应用。
[Abstract]:With the rapid development of petroleum industry, the corrosion problem of acid gas such as COSP 2 has become an important problem restricting the rapid and effective development of gas field. In view of this situation, it is necessary to analyze the corrosion law of fracturing pipe string. On this basis, the corrosion inhibitor suitable for well-killing fluid is selected. In this paper, the reason of corrosion failure of fracturing pipe string is studied, and it is found that local corrosion of oil tubing is formed after long immersion in well killing fluid. The corrosion phenomenon on the surface of the oil pipe is caused by O _ 2 and COSP _ 2, but the existence of a large number of active chlorine ions in the well killing fluid accelerates the occurrence of pitting corrosion under the scale. The three kinds of corrosion promote each other and cause the serious corrosion of the tubing. It is considered that under the action of formation high temperature and long time, the water in the well killing fluid gradually loses, the salt is precipitated on the outer wall of the tubing, and a layer of scale is formed, which creates the conditions for the occurrence of point corrosion, while in the inner wall of the tubing, The water in the fluid can not be lost, so it can not form scale, so the corrosion is lighter. Therefore, the tubing should be avoided from being used in the downhole for a long time. The corrosion rate of N80 steel and 13Cr stainless steel in three kinds of high-specific heavy pressure well fluids was studied. The corrosion order of the corrosion rate of N80 steel and 13Cr stainless steel in three kinds of high-specific heavy pressure well fluids was obtained as follows: sodium formate well killing fluid of NaNO3 well killing fluid of KCl fracturing fluid, and the corrosion rate of N80 steel and 13Cr stainless steel in three kinds of high-specific heavy pressure well fluids was studied. The corrosion inhibition effect of different corrosion inhibitors on N80 steel was evaluated for KCl well killing fluid N80 steel system, and it was found that when potassium silicate and polyacrylamide were mixed at 1:1, the corrosion inhibition effect could reach more than 90%. The corrosion inhibitor formula has been applied to the field application of Yu Daqing peripheral gas field. Corrosion detection of various corrosion inhibitor injection pipelines has been carried out. The results show that the corrosion inhibitor is mild and the corrosion inhibition effect is good. It has been applied successfully in the corrosion control of Daqing peripheral gas field.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE983
，

本文编号：2049184