海上W油田 32ＣｒＭｏ钢射孔枪腐蚀行为实验研究

针对32CrMo钢射孔枪在高含二氧化碳气体分压井筒中的腐蚀问题，利用高温高压釜开展腐蚀实验，对腐蚀产物膜进行理化特征分析，研究了温度，二氧化碳分压，流速和含水率等因素对 32CrMo 钢腐蚀速率的影响?结果表明，40℃温度条件下，32CrMo钢腐蚀产物膜为单层结构，对基体的保护作用较弱；80℃时，腐蚀产物膜为双层结构，对腐蚀介质有一定的屏蔽阻挡作用；130℃时，上层产物膜规则致密，对基体的防腐保护作用进一步增强?32CrMo钢的腐蚀速率随温度升高呈下降趋势，随二氧化碳分压的升高呈对数关系增加，随流速的增大呈线性增加，随腐蚀介质含水率的升高而急剧增加?基于实验结果，建立了多因素综合腐蚀速率工程预测模型，为工程上32CrMo钢腐蚀速率评价提供参考?

Experimental Study on Corrosion Behavior of 32CrMo Steel Perforating Gun in South China Sea W Oilfield

Aiming at the corrosion problem of 32CrMo perforating gun in high CO₂ gas partial pressure wellbore, the corrosion experiment was carried out in high temperature and high pressure kettle, the physical and chemical characteristics of corrosion product film were analyzed, and the effects of temperature, CO₂ partial pressure, flow rate and water content on the corrosion rate of 32CrMo steel were studied. The results show that the corrosion product film of 32CrMo steel is singlelayer structure and has weak protective effect on the matrix at 40 ℃ ; at 80 ℃ , the corrosion product film is a double-layer structure, which can shield and block the corrosion medium; at 130 ℃, the upper product film is regular and dense, and the anti-corrosion protection of the substrate is further enhanced. The corrosion rate of 3CrMo steel decreases with the increase of temperature, increases logarithmically with the increase of CO₂ partial pressure, increases linearly with the increase of flow rate, and increases sharply with the increase of water content of corrosion medium. Based on the experimental results, an engineering prediction model of multi factor comprehensive corrosion rate is established, which provides a reference for the evaluation of corrosion rate of 32CrMo steel in engineering.