P110钢冲刷腐蚀预测模型的构建及其机理研究  

Construction and Corrosion Mechanism of Erosion-corrosion Prediction Model for P110 Steel

作　　者：马文祺 王勤英 宋宇辉 符昌友 张兴寿 罗晓芳 西宇辰 董立谨 张华礼 张智 MA Wenqi;WANG Qinying;SONG Yuhui;FU Changyou;ZHANG Xinshou;LUO Xiaofang;XI Yuchen;DONG Lijin;ZHANG Huali;ZHANG Zhi(School of New Energy and Materials,Southwest Petroleum University,Chengdu 610500,China;Petroleum Engineering School,Southwest Petroleum University,Chengdu 610500,China;Engineering Technology Research Institute,PetroChina Southwest Oil&Gas field Company,Sichuan Guanghan 618300,China)

机构地区：[1]西南石油大学新能源与材料学院,成都610500 [2]西南石油大学石油与天然气工程学院,成都610500 [3]中国石油西南油气田公司工程技术研究院,四川广汉618300

出　　处：《表面技术》2024年第10期110-123,共14页Surface Technology

基　　金：国家自然科学基金(52174007);四川省省院省校项目(2023YFSY0017)。

摘　　要：目的探究高温高压环境下P110钢在不同冲刷速度和角度下的腐蚀行为规律,揭示其冲刷腐蚀机理,建立腐蚀预测模型,以期指导油气田材料腐蚀防护与腐蚀预测。方法采用电化学工作站和高温高压反应釜,开展高温高压冲刷腐蚀实验。采用金相显微镜、扫描电子显微镜、X射线衍射仪等对冲刷腐蚀前后材料的微观组织结构、化学成分及物相进行表征。此外,通过调研文献数据,基于随机森林(Random Forest,RF)算法构建了P110钢的冲刷腐蚀预测模型,并开展了预测准确性研究。结果在3m/s的冲刷速度下,随着冲刷角度的增加,自腐蚀电流密度由30°的2.19×10^(-4)A/cm^(2)降低到90°的1.449×10^(-4)A/cm^(2)。在30°的冲刷角下,随着冲刷速度的增加,自腐蚀电流密度由0m/s的6.30×10^(-5)A/cm^(2)增加到3 m/s的2.19×10^(-4)A/cm^(2)。腐蚀产物具有双层膜结构,外层主要由FeCO_(3)组成,内层主要为Fe_(2)O_(3)。腐蚀预测模型分析结果表明:温度对P110钢的腐蚀速率影响程度最大,其次是CO_(2)和冲刷速度。结论在高温高压环境下,P110钢能够产生Fe_(2)O_(3)和FeCO_(3)的双层腐蚀产物膜,随着冲刷速度的增加和角度的降低,腐蚀产物膜完整性破坏,腐蚀加剧。腐蚀预测模型具有良好的性能,能够有效预测腐蚀速率。As a common oil well pipe material in the oil and gas industry,P110 steel is prone to erosion corrosion at high temperature,high pressure,and high salinity flowing media,which threatens the safety of oil and gas development.In this paper,P110 steel was taken as the research object,and a high temperature and pressure erosion corrosion experiment was carried out by electrochemical workstation and high temperature and pressure reactor.The microstructure,chemical composition and phase composition of the material before and after erosion corrosion were characterized by metallographic microscope,scanning electron microscope(SEM)and X-ray diffractometer(XRD).The erosion corrosion behavior and mechanism of materials under different erosion speeds and angles in a high temperature and pressure environment were investigated.In addition,the corrosion prediction model of P110 steel was constructed based on the random forest(RF)algorithm,through the investigation of literature data.Then the prediction accuracy and corrosion influencing factors were analyzed.The results showed that the corrosion current density(Jcorr)decreased with the increase of erosion angle from 2.19×10^(-4) A/cm^(2) at 30°to 1.44×10^(-4) A/cm^(2) at 90°at the erosion speed of 3 m/s.At the erosion angle of 30°,the Jcorr increased from 6.30×10^(-5) A/cm^(2) at 0 m/s to 2.19×10^(-4) A/cm^(2) at 3 m/s.This was because the mass transfer time decreased with the increase of erosion speed and the decrease of angle,and the synergistic effect of tangential and normal stress enhanced as the increase of erosion speed and the decrease of erosion angle.Thus,the integrity and thickness of the corrosion product film were reduced,accelerating the corrosion.The–HCO_(3) and CO_(3)2-,produced by CO_(2) dissolution,and the presence of Cl-in the solution greatly increased the reaction activity of the P110 steel interface and decreased the pH of the solution,forming a corrosion product film dominated by FeCO_(3).Due to the diffusion of Fe^(2+)from the surface of P110 st

关 键 词：P110钢 冲刷腐蚀 高温高压 机器学习 随机森林 

分 类 号：TG174[金属学及工艺—金属表面处理]