塔河油田点蚀测试及评价技术应用

 系统分析了塔河油田点蚀测试和评价技术的特点及存在的问题。通过引进3D点蚀测深仪及改进点蚀评价方法,对塔河油田不同区块的点蚀状况进行评级。对地面生产系统管道开展了腐蚀规律分析、缓蚀剂防护及新材质抗腐蚀效果现场评价,得出塔河油田主力区块单井及油气混输管道CO₂/H₂S环境与点蚀速率的关系:在介质流体温度为50~70℃条件下,点蚀速率为P_CO2/P_H2S的多项式函数,呈波动规律分布。评价了单井管道及集输管道的缓蚀剂工艺防护效果,结果表明:对于布站较多的长距离集输管道应采用分段加注缓蚀剂方式防护,管道中段缓蚀率较高;布站少或距离较短的管道应采用端点加注缓蚀剂方式防护,从管道起点到末端缓蚀率升高;其中,TH10244单井管道采用"清管器+缓蚀剂"预膜防护工艺后缓蚀率高达70%。研究表明新材质(BX245-1Cr)挂片在地面集输系统试验管道中较20^#钢挂片点蚀速率下降了43.7%。

Application of Test and Evaluation Technology of Pitting Corrosion in Tahe Oilfield

The features and existing problems of Tahe Oilfield pitting corrosion testing and evaluation technology were systematically analyzed. Through 3D pitting depth sounder device and improved pitting evaluation methods, the pitting conditions of different blocks of Tahe Oilfield were rated. The corrosion behavior was analyzed and the protective effect of inhibitor and anti-corrosion effect of the new material of production system pipes on the ground were evaluated. The relationship of the mixed CO₂/H₂S environment and the pitting corrosion rate of single-well pipes and oil and gas mixed pipelines of the main block in Tahe Oilfield were obtained. At the fluid temperature of 50~70℃, corrosion pitting rate is a polynomial function of P_CO2/P_H2S, fluctuating regularly distributed. The protective effect of inhibitor craft of single-well pipes and gathering pipelines was evaluated. The results show that: for long-distance gathering pipeline or pipelines having more stations, the inhibition rate is higher in the middle of the pipeline, and the filling way of inhibitors should be segmented; for shorter-distance pipeline or pipelines having the fewer stations, the inhibition rate increased from the beginning to the end of the pipeline and inhibitors should be used at endpoint filling mode. Through the application of "pigging+inhibitor" pre-film protection technology for TH10244 single well pipe, the inhibition rate increased by 70%. The results have shown that pitting corrosion rate of new material (BX245-1Cr) coupon of gathering system of pipelines on the ground decreased by 43.7% compared with 20^# steel coupon.