【正文】 Master of Engineering By Cao Yanguang (Material Engineering) Dissertation Supervisor: Professor. Ma Xinpei Senior Engineer. Zhang Qingsheng Oct., 2020 III 論文題目： 油田集輸管線腐蝕及防護(hù)研究 學(xué)科專業(yè)： 材料工程 學(xué)位申請人： 曹言光 指導(dǎo)教師： 馬新沛教授，張慶生高級(jí)工程師 摘 要 近幾年隨著中原油田綜合含水的上升和大量酸化、壓裂、三次采油等措施的廣泛實(shí)施，中原油田集輸管線介質(zhì)的腐蝕特性發(fā)生較大變化，同時(shí)集輸管線也在進(jìn)一步老化，管線及外防工程施工質(zhì)量不理想，內(nèi)防措施實(shí)施少，緩蝕劑加藥方式存在很大缺陷，造成了日益突出的腐蝕問題，因管線腐蝕造成的經(jīng)濟(jì)損失逐年上升。 本文通過對中原油田集輸管線腐蝕狀況調(diào)查、集輸管線介質(zhì)特性分析、集輸管線材質(zhì)及腐蝕產(chǎn)物成 份分析，得出集輸管線腐蝕特征和主要腐蝕因素。通過研究，本文得出以下結(jié)論： 中原油田集輸管線 介質(zhì)流型以過渡流和間隙流為主，集輸管線氣液相混合流速較高，管線腐蝕中的沖刷作用很嚴(yán)重。 介質(zhì)綜合含水上升 和 大量上產(chǎn)措施使介質(zhì)腐蝕特性 發(fā)生 變化，使得腐蝕問題更加復(fù)雜和嚴(yán)重。 通過加速腐蝕 、 點(diǎn)蝕 和 現(xiàn)場耐土壤腐蝕埋片評(píng)價(jià)試驗(yàn)，四種碳鋼集輸管材以 40鋼耐介質(zhì)腐蝕性能最好。但采用自己研制的 復(fù)合型 緩蝕劑的 緩 蝕 率 是 咪唑啉類緩蝕劑的 ～ 倍， 緩蝕 性能大大提高。 關(guān) 鍵 詞： 集輸管線 腐蝕 防護(hù) 緩蝕劑 論文類型： 應(yīng)用研究 V Title: Research on Corrosion and Prevention of gathering lines of Oilfield Speciality: Materials Engineering Applicant: Cao Yanguang Supervisor: Prof. Ma Xinpei， SE. Zhang Qingsheng ABSTRACT With the increasement of total watercut and widely implementation of aboundent treatments such as acidizing, frac and third oil recovery, the property of medium gathering lines in Zhongyuan Oilfield has greatly changed and ageing of the gathering lines has also increased. At the same time, construction of lines and exterior preservation is in low quality, there are only little percent of the branch and main lines are adopted with inner preservation, and there is serious shorting with the dosing style of anticorrosive agent. The problem of corrosion has been getting more serious, and economic loss due to line corrosion has been raising year by year. This thesis found out the corrosion characteristic and main reason of gathering lines through investigating the corrosion status, analyzing the special property of the medium, material of lines and position of corrosion oute. Scientific assessment method of anti corrosion agent through analyzing the condition of multiple phase flow was established in view of the properties of corrosion medium. Technology of anti corrosion agent was improved and site test was made, the preservation effect and economic benefit were all improved. This thesis obtained these following conclusions: The main medium flow pattern of gathering lines are interim flow and interspace flow. The mixed current of gasliquid phase is much high, resulting in serious corrosion in gathering lines. The material of gathering lines is mainly 20 and 40 steel, ageing degree of which is much seriuos. Only 20 to 30 percent of the main and branch lines are adopted with inner anticorrosion, although there are many kinds of inner anticorrosion insulation. The outside anticorrosion technology has been also aged. Joint and outside corrosion is nearly equal to inner corrosion, and corrosion boring is much serious. Medium property has been greatly changed due to water content has ascended and adoption of aboundent treatments such as acidizing, frac and third oil recovery, resulting in more plex and serious corrosion. There are some regular patterns between medium and gathering lines corrosion. The affection of medium temperature increases when temperature increases, the largest VI scale is between 50℃ and 80℃ . Corrosion rate increases doubly when degree of mineralization increases between 0 and 10 104mg/l, but being steady even has decline trend when degree of mineralization is more than 15 104mg/l. Corrosion rate has a linear relation with medium current speed when medium current speed is 0～ 2m/s and there is no oxygen. Water content has different affection in different period area. Corrosion rate does not change too much when water content is between 0 and 30%, but increases obviously when water content is between 40 and 70%, and smooth when water content is above 70%. Partial pressure of CO2 has a large affection on corrosion. Corrosion rate increases obviously when partial pressure of CO2 increases between 0 and . Corrosion rate drops when dissolution oxygen is more than due to deactivation of the corrosion product. pH has a largest affection to corrosion rate when pH is between 4 and 6, thus corrosion control will be most economical and effective. Acceleration corrosion, spot corrosion and resist soil corrosion slicelayed experiments proved that anticorrosion performance of 40 steel is better than that of other three kinds of carbon steel. The imidazoline and amine salt anticorrosion, of which concentration is from 100 ppm to 400ppm, have only to 32 percent anticorrosion capacity when medium current speed is , and can not meet corrosion control requirement. However the anticorrosion capacity of posite anticorrosion agent, which we developed is ～ times more than that of imidazoline anticorrosion agent. Individual well dosing scheme, Impact dosing circle from endpoint of gathering lines and dosing amount have been optimized, After three circles of field test, the general iron level declined percent, the bacteria content declined 1～ 2 quantity degree, corrosion rate declined 8～ 50 percent and can be controlled under , moreover there is no point corrosion. The research of this thesis has acquired noticeable economic and social benefit. Keywords: Gathering lines Corrosion Preservation Anticorrosive Agent Thesis type: Application Foundation VII 目 錄 第一章 緒 論 ................................................................................................................... 1 研究的背景及意義 ................................................................................................ 1 國內(nèi)外發(fā)展動(dòng)向 .................................................................................................... 1 中原油田集輸管線腐蝕狀況調(diào)查 ........................................................................ 5 調(diào)查方案 ...............