【作者】 徐士祺；

【导师】 袁宗明；

【作者基本信息】 西南石油大学 ， 油气储运工程， 2013， 博士

【摘要】 延长油田股份有限公司截至目前已建成采油厂22个,注水站309座,注水井2302口,注水管线总长度为400多千米,通过注水充分地补充了地层自身能量,提高了原油产量及采收率,为当地原油的正常生产做出了极大的贡献。根据近年来的现场调查,延长油田产出水具有矿化度高、pH值偏碱性,油田注水管线的腐蚀状况极为严形重。随着延长油田产出液含水的逐步上升和注水开发规模的加大以及注水管网使用年限的增加,注水管网系统的腐蚀问题近几年内呈现出急剧加重趋势,延长油田注水管道的腐蚀防治问题已刻不容缓。因此,针对延长油田注水管线出现的内腐蚀问题,为了弄清其腐蚀发生的内在原因,认识其腐蚀规律,有针对性地进行腐蚀防治,开展了本论文的研究,以保障延长油田注水管道的安全连续运行,延长管道的使用寿命。本论文的主要研究工作有：(1)延长油田注水管线内腐蚀现状调研与注水水质分析。通过对延长油田安塞-永坪段因腐蚀报废注水管段的现场开挖,调研分析了其内腐蚀和防腐技术现状；在对注水水质分析的基础上,研究了注水水质的腐蚀性。(2)蟠龙-余家坪段注水管道内腐蚀行为研究。利用室内挂片实验和电化学测试对管材的耐蚀性进行分析,与现场测试数据进行对比,对影响腐蚀的主要因素进行了实验研究；得出腐蚀速率与温度、时间、流速等的变化关系,并对其规律进行分析。利用能谱分析和扫描电镜技术对腐蚀过程中产生的垢样进行分析,研究了注水管线结垢的主要成分及垢下腐蚀的机理。(3)流速对注水管道内腐蚀行为研究。利用相似原理,设计制造了实验装置,通过设计的试片卡槽实现了腐蚀试片单面动态腐蚀,以模拟实际管线的内壁腐蚀现象。并通过改变转速模拟流速的变化来研究流速对管道腐蚀速率的影响。这是对现场进行模拟的实验技术创新,得到了流速与腐蚀速率的关系,结果表明流速对腐蚀速率影响明显。(4)腐蚀预测数学模型的建立。在测得的实验数据基础上,建立了延长油田注水管线腐蚀速率与温度、时间及流速之间的数学模型,可以初步预测当主要影响因素发生变化时延长油田管线钢的腐蚀速率,从而为延长油田注水管线在环境改变的条件下的防腐蚀工作提供理论指导。(5)缓蚀剂评价研究。针对延长油田注水的水质特点,筛选评价延长油田专用缓蚀剂是提高注水管线寿命的重点。为了评价缓蚀剂的缓蚀效果,将研制的HJF-94、ODD、TC-610、CQ-HO2和LED五利,缓蚀剂在模拟延长油田生产作业的环境中进行室内实验评价。确定了每种缓蚀剂的最佳作用量及最佳的缓蚀效果,通过对比表明：缓蚀剂TC-6l0和CQ-HO2的绥蚀性能优于其他缓蚀剂,且缓释效率较高：同时，通过实验对两种缓蚀剂按不同混合比例进行了复配实验。实验结果表明：动态条件下单独使用TC-610缓蚀剂的缓蚀效果更佳。(6)延长油田注水管线内防腐措施研究。在以上研究的基础上推荐了适合延长油田田注水管道内腐蚀的防护措施。更多还原

【Abstract】 Yanchang Oilfield Co., Ltd. has built22oil production plant,309water injection plant,2302injection wells, the total length of water injection pipelines is400km so far, the formation energy is greatly complated, in order to increase crude oil production and oil recovery, which make a great contribution for normal local crude oil production. According to field investigation in recent years, water produced by the oil field has high salinity and alkaline pH, so oilfield water injection pipeline corrosion situation is extremely serious. With water cut produced gradually rising, the scale of water injection development is increasing and the service life of water injection network is lengthened, corrosion of the water injection line in Yanchang oilfield in recent years has a sharp increased trend, so the problem of water injection pipeline corrosion prevention has become essential. Therefore, to ensure the water injection pipeline in Yanchang oilfield safety and continuous operation and to prolong the life of the pipeline for corrosion protection, clarifying the underlying causes of the corrosion and understanding the corrosion law is studied in this paper.The main research work of this paper is:(1) Corrosion investigation of Yanchang water injection pipeline internal corrosion status and analysis of water injection water quality. Through the survey of AnSai—YongPing water injection pipe sections which are abandoned because of corrosion and conducting on-site excavation, understand the pipeline internal corrosion and anticorrosion technology present situation; Through component analysis of the injection water quality, study the corrosion of water injection water quality.(2) Internal corrosion behavior study of water injection pipeline in PanLong—YongPing section. By interior coupon experiment and electrochemical testing, tubing corrosion resistance are analyzed; And compared with field test data, do the experimental researches on the main factors influencing the corrosion; Work out its regularity of corrosion rate and the changes with temperature, time, etc, and analyze the law. Using the energy spectrum analysis and SEM analysis of the corrosion process of scaling samples, analyzing the main composition of scaling in water injection pipeline and the mechanism of corrosion under the scaling.(3) Internal corrosion behavior research on water velocity of water injection pipeline. By similarity principle, design experiments independently which change speed instead of velocity change is used to study the influence of the velocity to the pipeline corrosion rate, which is used for simulating the scene of theoretical innovation, getting the relationship between velocity and the corrosion rate, results show that the velocity influence on the corrosion rate significantly.(4) Establishment of the mathematical model. On the basis of measured data getting from the experiment, establishing the mathematical model between corrosion rate of water injection pipeline with temperature, time and velocity to preliminary forecast Yanchang pipeline steel corrosion rate when main influent factors changes, and then provide a certain theoretical guidance of corrosion protection work in order to prolong oilfield water injection pipeline under the changing condition of environment.(5) Study of corrosion inhibitor. For water quality characteristics in Yanchang oilfield water injection line, developing the Yanchang oilfield special corrosion inhibitor is a major research contents and key of this paper. To evaluate corrosion control effect of corrosion inhibitors, doing the interior test evaluation with five kinds of corrosion inhibitors which are developed HJF-94, ODD, TC-610, CQ-HO2and LED in the simulation of the oil field production conditions. Determining the optimum dosage of each inhibitor and best corrosion control effect, comparing the five corrosion inhibitors, the results show that the corrosion control effect of TC-610and CQ-HO2is superior to other corrosion inhibitors; At the same time, carrying out the experiment of two kinds of corrosion inhibitors by combination test experiments with different proportion distribution. Results show that effect of using alone the TC-610corrosion inhibitor is much better, and this is a significant technological innovation.(6) Study on measures of internal corrosion protection for YanChang water injection pipeline. On the basis of literature research, the suitable measures of internal corrosion protection for Yanchang oilfield water injection pipeline are recommended.更多还原