| 摘要: |
| 采用高矿化度油田水作为环空保护液基液易增加油套管钢腐蚀开裂的风险,因此,需对P110S钢在油田水环空保护液中的腐蚀风险进行评估。在对油田水和P110S钢的化学组分进行分析的基础上,用高温高压釜模拟现场工况,开展温度为200 ℃、CO2分压为10 MPa、H2S分压为2 MPa条件下的失重腐蚀和四点弯曲实验,并用SEM与EDS分析腐蚀产物形貌和成分,最后对试样进行截面分析。结果 表明:P110S钢在高温高酸性工况下未发生应力腐蚀失效,腐蚀速率为0.098 5 mm/a,试样表面存在严重的点蚀和局部腐蚀；截面分析显示试样表面腐蚀产物膜厚度为63 μm,金属基体腐蚀严重,P110S油套管钢在此工况下面临较大的腐蚀失效风险。为了抑制管材的腐蚀,建议使用淡水或矿化度较低的井场水作为环空保护液基液。 |
| 关键词: 酸性油气田 P110S钢 油田水环空保护液 腐蚀风险 |
| DOI：10.3969/j.issn.1007-3426.2021.06.012 |
| 分类号: |
| 基金项目:2020年中石化科研项目“顺北一区5号断裂带提质提速钻完井技术研究”(P20002) |
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| Corrosion risk assessment of P110S steel in annulus protection fluid in high salinity oilfield water |
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Huang Zhijuan1,2, Du Chunchao1,2, Long Wu1,2, Zang Shuo3, Liu Zhendong3, Zeng Dezhi3
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1. Petroleum Engineering Technology Research Institute of Sinopec Northwest Oilfield Company, Urumqi, Xinjiang, China;2. Sinopec Key Laboratory of Fracture-cave Reservoir Enhanced Oil Recovery, Urumqi, Xinjiang, China;3. State Key Laboratory of Oil & Gas Reservoir Geology and Exploration, Southwest Petroleum University, Chengdu, Sichuan, China
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| Abstract: |
| Using high-salinity oilfield water as the annulus protection liquid base fluid can easily increase the risk of corrosion and cracking of tubing and casing steel. Therefore, it is necessary to evaluate the corrosion risk of P110S steel in the oilfield water annulus protection liquid. Firstly, the chemical components of oil field water and P110S steel were analyzed. Then, the field conditions were simulated by using a high-temperature autoclave. The weightlessness corrosion and four-point bending experiments were carried out under the temperature of 200 ℃, CO2 partial pressure of 10 MPa and H2S partial pressure of 2 MPa, and the morphology and composition of corrosion products was analyzed by using SEM and EDS. Finally, the cross-section of the sample was analyzed. The results show that P110S steel does not suffer from stress corrosion failure under high temperature and high acid conditions. The corrosion rate is 0.098 5 mm/a, severe pitting and local corrosion can be observed on the surface of the sample. Cross-sectional analysis shows that the thickness of corrosion product film on the sample surface is 63 μm, and the metal matrix is corroded seriously. P110S tubing and casing steel faces a greater risk of corrosion failure under this working condition. In order to suppress the corrosion damage of the pipes, it is recommended to use fresh water or low-salinity well site water as the annulus protection liquid base fluid. |
| Key words: sour oil and gas field P110S steel oil field water annulus protection fluid corrosion risk |
