CO2/H2S共存条件下集输管道选材的新方法及应用

在CO₂/H₂S共存条件下集输管道中,管道发生腐蚀的可能性急剧增大,因此集输管道的选材至关重要。若选择管材级别较低,则会严重影响管道的正常生产；若管材级别较高,会引起经济成本的浪费。为了使集输管道在CO₂/H₂S共存条件下选材更加合理。在CO₂/H₂S共存腐蚀速率预测模型的基础上,提出了一种新的集输管道选材方法,新方法的步骤为：计算材质的均匀腐蚀速率,腐蚀速率应满足NACE 标准中腐蚀速率的控制值(小于0.076mm/a),结合管道的设计寿命、剩余强度和经济性评价,确定在CO₂/H₂S共存体系下集输管道的材质。以某油田集输管道为示例,根据新方法选择的材质与实验得到的管材结果一致,验证了新方法的准确性。集输管道选材新方法在保证集输管道安全运行的前提下,能够有效降低管材质选择的成本,有利于保证集输管道的安全性和经济性。

New Method and Application of Gathering Pipeline Material Selection in CO2/H2S Coexisted Corrosion Environment

Under the condition of CO₂/H₂S coexistence, the possibility of pipeline corrosion increases sharply, so the selection of materials for gathering and transportation pipelines is very important. If the pipe material grade is lower, it will seriously affect the normal production of the pipe; if the pipe material grade is higher, it will cause a waste of economic costs. In order to make the selection of materials for gathering pipelines under the conditions of CO₂/H₂S coexistence more reasonable, a new method for selecting materials for gathering pipelines is proposed on the basis of the prediction model of CO₂/H₂S coexistence corrosion rate. The steps of the new method are: calculated the uniform corrosion rate of the material, the corrosion rate should meet the control value of the corrosion rate in the NACE standard (less than 0.076mm/a), and determined the material of the gathering pipeline under the CO₂/H₂S coexistence system based on the design life of the pipeline, remaining strength and economic evaluation. Taking the gathering and transportation pipeline of an oil field as an example, the material selected by the new method is consistent with the experimental results, which verifies the accuracy of the new method. The new method of material selection for gathering and transportation pipelines can effectively reduce the cost of pipe material selection on the premise of ensuring the safe operation of gathering and transportation pipelines, which is beneficial to ensure the safety and economy of gathering and transportation pipelines.