引用格式:

周祥,叶正荣,刘翔,伊然,赵志宏,钟银,林学强,孙建波.深层油藏采油井不同CO2分压条件下N80钢腐蚀行为研究[J].天然气与石油,2025,43(4):108-114.doi:10.3969/j.issn.1006-5539.2025.04.015
ZHOU Xiang, YE Zhengrong, LIU Xiang, YI Ran, ZHAO Zhihong, ZHONG Yin, LIN Xueqiang, SUN Jianbo.Research on N80 steel corrosion behavior in deep reservoir production wells under various CO2 partial pressure conditions[J].Natural Gas and Oil,2025,43(4):108-114.doi:10.3969/j.issn.1006-5539.2025.04.015

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DOI:

10.3969/j.issn.1006-5539.2025.04.015

作者:

周祥1　叶正荣1　刘翔1　伊然1　赵志宏1　钟银2　林学强3　孙建波3
ZHOU Xiang1, YE Zhengrong1, LIU Xiang1, YI Ran1, ZHAO Zhihong1, ZHONG Yin2, LIN Xueqiang3, SUN Jianbo3

作者单位:

1. 中国石油勘探开发研究院,　北京　100083; 2. 中国石油吐哈油田分公司,　新疆　哈密　839009; 3. 中国石油大学(华东)材料科学与工程学院,　山东　青岛　266580
1. PetroChina Research Institute of Petroleum Exploration and Development, Beijing, 100083, China; 2. PetroChina Tuha Oilfield Branch, Hami, Xinjiang, 839009, China; 3. School of Materials Science and Engineering, China University of Petroleum(East China), Qingdao, Shandong, 266580, China

关键词:

深层油藏;CCUS;CO2分压;N80钢
Deep oil reservoir; CCUS; CO2 partial pressure; N80 steel

摘要:

近年来,CO2捕集与利用逐步在埋深＞ 3 000 m的油藏开展试验,生产过程中井筒温度压力高,CO2相态存在超临界态和气态,对N80钢在不同CO2分压条件下腐蚀行为缺乏全面认识,导致采油井防腐设计存在一定盲目性。为此,探究不同CO2相态环境下的腐蚀行为及腐蚀机理。首先采用失重法研究了N80钢在不同CO2分压条件下的腐蚀速率,然后采用扫描电镜、能谱分析、X射线衍射等方法研究了腐蚀产物形貌与成分。研究结果表明,当CO2分压为0.4~18.0 MPa,N80钢平均腐蚀速率呈现出先升高后降低再升高的趋势,并在CO2分压=10.5 MPa时出现最大值;不同CO2分压条件下腐蚀产物膜均为晶体状FeCO3颗粒沉积而成,腐蚀形态均表现为典型的均匀腐蚀;13.0~18.0 MPa的高CO2分压条件下,腐蚀产物膜双层膜厚度增大,对基体的保护性增强。因此,建议在CO2分压＜2.0 MPa环境下采用N80钢+加注缓蚀剂的方式,CO2分压＞4.0 MPa环境下采用更耐蚀的材料或涂镀层材料。研究结果可为深层油藏CO2驱材料选择与防腐设计提供借鉴。
In recent years, CO2 Capture and Utilization pilot tests have been carried out gradually in oil reservoirs deeper than 3 000 m. During the oil recovery process, the wellbore temperature and pressure are high, with CO2 existing in both supercritical and gaseous states. There is a lack of comprehensive understanding of N80 steel's corrosion behavior under different CO2 partial pressure conditions, resulting in a certain degree of blindness in the corrosion protection design of production wells. Therefore, this paper investigates the corrosion behavior and mechanisms under different CO2 phase environments. The weight loss method was used to study the corrosion rate of N80 carbon steel under different CO2 partial pressure conditions. Subsequently, Scanning Electron Microscopy(SEM), Energy Dispersive Spectroscopy(EDS), X-ray Diffraction(XRD) and other techniques were used to analyze the morphology and composition of the corrosion products. The results show that when the CO2 partial pressure range is 0.4~18.0 MPa, the average corrosion rate of N80 steel shows a trend of initially increasing, then decreasing, followed by increasing again, reaching its maximum value when CO2 partial pressure is 10.5 MPa. Under all tested CO2 partial pressure conditions, the corrosion product films consist of deposited crystalline FeCO3 particles, with the corrosion morphology consistently showing typical uniform corrosion. Under high CO2 partial pressure conditions(13.0~18.0 MPa), the double-layer corrosion product film thickness increases, enhancing its protective effect on the substrate. Therefore, it is recommended to use N80 steel with corrosion inhibitor addition in environments with CO2 partial pressure below 2.0 MPa; whereas for environments with CO2 partial pressure above 4.0 MPa, more corrosion-resistant materials or coated materials should be used. The research findings provide valuable reference for material selection and corrosion protection design in deep reservoir CO2 flooding operations.

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