钻杆溶解氧腐蚀影响因素分析

溶解氧腐蚀是钻杆使用寿命下降的最重要的原因。通过试验研究和文献分析,论述了钻井施工过程中服役环境、溶解氧浓度、泥浆pH值、井下温度、压力、钻井液、钻杆材质等诸多因素对钻杆溶解氧腐蚀的影响。分析认为,氧浓度对钻杆腐蚀起主导作用,钻杆腐蚀速度随着氧浓度的增加而加快;防止钻杆氧腐蚀最简便的措施是提高钻井液的pH值,最有效的办法是采用除氧剂对钻井液进行除氧。

Analysis of Influencing Factors on Dissolved Oxygen Corrosion of Drill Pipe

Dissolved oxygen corrosion plays the most critical role in service-life reducing of the drill pipe. Influencing factors responsible for the said corrosion are identified by means of relevant experimental studies and literature analysis. The factors include the field service conditions of the drill pipe, concentration of dissolved oxygen, pH value of drilling fluid, well temperature, well pressure, drilling fluid and drill pipe material, etc. Based on the analysis, it is concluded that oxygen concentration acts as the leading factor responsible for the drill pipe corrosion, and such corrosion is speeding up along with the growth of the oxygen concentration. Accord- ingly, the co-authors put forward that for the purpose of preventing oxygen corrosion of the drill pipe, the simplest way is to enhance the pH value of the drilling fluid, while the most effective way is to remove the oxygen from the drilling fluid with the deoxidant.