论文总字数：31259字

摘 要

现阶段，我国诸多油田已进入中、后期开发阶段。新疆油气田集输管线系统的矿化度高，氯离子浓度高，温度较高，地质环境较差。影响新疆油气田管线系统套损因素很多，其中腐蚀占主导因素，造成了巨大的经济损失，而添加缓蚀剂是抑制腐蚀的一种有效、经济的防护措施。

本课题模拟新疆油气田集输管线系统，采用了旋转动态挂片失重法和电化学Tafel极化曲线进行了实验研究。通过单组份缓蚀剂浓度梯度试验得出，当腐蚀介质中三聚磷酸钠≥30mg/L对该系统的缓蚀效果较好，但饱和三聚磷酸钠溶液至多可使腐蚀介质中含量达到12.4726mg/L，无法起到缓蚀效果。因此，利用酸性缓蚀剂（HPAA、HEDP、ATMP等）来调节具有较好缓蚀效果的饱和碱性缓蚀剂三聚磷酸钠pH至5.0，以增加碱性缓蚀剂的溶解度来增强缓蚀效果。最终确定了三聚磷酸钠与HPAA、HEDP、ATMP、PBTCA的二组分复配配方，失重法实验得出4种100mg/L的二组分复配缓蚀剂缓蚀率基本达到90%，腐蚀速率lt;0.035mm/a。

但根据中石化的要求，缓蚀剂的总量应控制在100mg/L之内。通过对比缓蚀剂成分和含量对Q235钢缓蚀性能的影响得出，70mg/L（HEDP 三聚磷酸钠）与100mg/L（HPAA 三聚磷酸钠）缓蚀效果基本一致。所以，确定以70mg/L（HEDP 三聚磷酸钠）为主缓蚀剂，以HPAA、HEDP、ATMP为辅缓蚀剂，并以正交试验确定辅缓蚀剂对添加了主缓蚀剂后缓蚀性能的影响。正交试验实验结果表明，70mg/L（HEDP 三聚磷酸钠）、10mg/LHPAA、10mg/LATMP、5mg/LHEDP缓蚀配方效果最好，缓蚀率达到93.71%，年腐蚀速率为0.0226mm/a。

关键词： 腐蚀速率、缓蚀率、缓蚀效果、协同效应、缓蚀机理

Reserch on corrosion inhibitors of Xinjiang oil and gas gathering line without emulsifying tendency

ABSTRACT

At the present stage, many of the oil field development has entered the middle and late stage in our country. The feature of Xinjiang oil and gas gathering pipeline system is high salinity, high chlorine ion concentration, high temperature and poor geological environment. There are many factors that affect the pipeline system in Xinjiang oil and gas field. The corrosion is dominant factors, which causes the huge economic losses. And the method of adding corrosion inhibitor an effective and economic protection measures to restrain corrosion.

In this paper, the simulation of gas gathering and transportation pipeline system in Xinjiang oil and gas field has been carried out. The experimental study has been carried out by using the method of rotating dynamic weight loss and electrochemical Tafel polarization curve. The one-component corrosion inhibitor concentration gradient experiment suggests that, when the concertation of sodium tripolyphosphate is more than or equal to 30 mg / L in the corrosive medium, a good inhibition effect was obtained. But the saturated solution of trimeric sodium phosphate in the corrosive medium can’t more than 12.4726 mg/L, it has no corrosion effect. Therefore, adjusting pH value of the saturated solution of trimeric sodium phosphate to 5.0 by acid corrosion inhibitors (HPAA, HEDP, ATMP, etc.), which has a good inhibition effect, in order to improve the solubility of alkali corrosion inhibitors to enhance corrosion effect. The better inhibition effect was determined, the two component distribution formula constituted of the trimeric sodium phosphate and HPAA, HEDP, ATMP, PBTCA. The weight loss test results show that the 4 components of the two 100mg/L compound inhibitor corrosion rate of 90%, the corrosion rate of lt;0.035mm/a.

According to the requirements of sinopec, the amount of corrosion inhibitors should be controlled within 100 mg/L. It suggests that 70 mg/L (HEDP trimeric sodium phosphate) and 100 mg/L (HPAA trimeric sodium phosphate) corrosion effect is quite by comparing the composition and content of Q235 steel corrosion inhibitor performance. Therefor, the 70 mg/L (HEDP trimeric sodium phosphate) was regard to the main inhibitor, HPAA, HEDP, ATMP was subsidiary corrosion inhibitors. The inhibitor corrosion effects of add subsidiary corrosion inhibitors after add the dominating corrosion inhibitors was determained by orthogonal test. The results suggest that the best corrosion formula is 70 mg/L (HEDP trimeric sodium phosphate), 10 mg/LHPAA, 10 mg/LATMP and 5 mg/LHEDP, with a inhibitor corrosion rate of 93.71% and the annual corrosion rate of 0.0226 mm/a.

KEYWORDS: corrosion rate; corrosion inhibition efficiency; corrosion inhibition; synergistic effect; inhibition mechanism

目录

摘要 I

ABSTRACT II

第一章 绪论 1

1.1前言 1

1.2新疆油气田集输管线腐蚀现状和危害 1

1.2.1油气田管线腐蚀现状 2

1.2.2腐蚀给油气田管线带来的危害 3

1.3缓蚀剂的定义和作用机理 4

1.3.1缓蚀剂的定义 4

1.3.2缓蚀剂分类和作用机理 4

1.4国内外缓蚀剂研究概况 6

1.5论文研究内容和意义 7

第二章 试验方法与内容 9

2.1实验材料与药品 9

2.2实验仪器 10

2.3模拟溶液准备 11

2.4试验方法和原理 12

2.4.1乳化实验 12

2.4.2失重法 12

2.4.3电化学方法 13

第三章 实验结果与讨论 16

3.1引言 16

3.2乳化实验 17

3.3失重法筛选缓蚀剂 17

3.3.1单品种缓蚀剂的筛选 17

3.3.2单品种缓蚀剂梯度试验 20

3.3.3酸性缓蚀剂溶解三聚磷酸钠实验 27

3.3.4复配缓蚀剂筛选 31

3.3.5正交试验确定最佳复配比 34

3.4电化学方法研究缓蚀机理 37

3.4.1单组份缓蚀剂与空白对比 37

3.4.2复配缓蚀剂与空白对比 38

3.4.3 70mg/L（HEDP 三聚磷酸钠）与复配缓蚀剂对比 39

第四章 结论与展望 41

4.1结论 41

4.2展望 42

参考文献 43

致谢 46

第一章 绪论

1.1前言

近年来，人们对能源需求量的日益增加，石油与天然气已成为我国主要能源来源。但油气田开采与开发过程中所面临的环境问题日益恶化，大多油气田的产量逐年降低，油田采出液含水率却逐步增加。同时，由于开采技术的不成熟，在油气田开采天然气的过程中常伴随着凝析油、腐蚀气体的产生。油气田中通常为油-水-气混相流体，介质流态与成分十分复杂，流体中物质成分无疑会对集输管线系统产生重要影响，发生严重的腐蚀问题。

腐蚀可能不会立即对材料产生十分有害的行为，但它会对其机械强度、运行机制以及表面状态等方面产生较大影响进而导致严重的工艺失效。随着国内外油气田的不断开发，油气田设备及管线不断出现因腐蚀导致的穿孔、开裂等现象；石油和天然气的泄漏事故时有发生，对油田生产和人员安全带来了极大的安全隐患。在油气田开发过程中，油气田生产系统的采集器、管道、储罐等沿线各种工艺生产设备均会遭受严重的腐蚀，造成巨大的经济损失和安全隐患。

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