多相流动状态下原油对 X70钢 CO2腐蚀的影响

摘要

The corrosion of X70 steel at plug flow was simulated using the homemade experimental apparatus.The effects of crude oil on CO 2 corrosion of X70 steel was studied by an-alyzing the bolt surface morphology,corrosion rate with electronic microscope and bolt.The results show that the point of mixed oil and water inverse cannot serve as pipeline corrosion critical point.The corrosion protection of crude oil is only limited to the uniform corrosion instead of local corrosion.The local corrosion rate rises along with the increase of the content of crude oil;The corrosion protective function of crude oil on uniform corrosion is obvious.Firstly, it reduces surface wetting area and the contact with the corrosive medium of opportunities. Secondly,it increases the viscosity of the mixture of corrosive medium to slow the coupon surface mass transfer. Thirdly, the unknown corrosion inhibition components exist in high waxy crude oil.%利用自制实验装置模拟起伏管路段塞流动条件下 X70钢 CO 2腐蚀问题，通过电子显微镜、腐蚀挂片等对挂片表面形貌、腐蚀速率情况进行分析，研究了多相流动状态下原油对 X70钢 CO 2腐蚀速率的影响。结果表明：油水反相点不能作为油水混输管线腐蚀临界点；原油对 X70钢腐蚀防护作用仅局限于均匀腐蚀，对局部腐蚀无防护作用，随着原油含量的增加，局部腐蚀速率可能升高；原油对均匀腐蚀的防护作用主要体现在：降低挂片表面润湿面积，减小挂片与腐蚀介质接触机会；增大腐蚀介质的混合黏度，降低挂片表面传质速度；高含蜡原油内的许多未知成分具有缓蚀作用。