注空气过程中井下管柱氧腐蚀防护技术研究

发布时间：2018-07-05 06:08

  本文选题：注空气 + 氧腐蚀　； 参考：《中国石油大学(华东)》2015年硕士论文

【摘要】：作为一项富有创造性的提高采收率新技术,近年来,注空气驱油技术在国内外受到了越来越多的重视。但由于高压空气的注入,使井下管柱处于高氧分压、高温、有水或潮湿的环境,从而遭受严重的腐蚀破坏,影响了油田的正常生产。由现场施工经验可知,腐蚀作为注空气/空气泡沫提高采收率技术不可避免的问题严重制约着该技术的应用与推广。为此,通过失重法、XRD分析、EDS分析以及SEM分析等方法,对井下管柱腐蚀机理与腐蚀规律进行了深化研究。结果表明:(1)氧腐蚀速率随着压力的增大而加快,即使在溶解氧浓度非常低(6mg/L)的情况下,N80、P110钢的腐蚀速率也大于行业标准(0.076mm/a),发生严重腐蚀。(2)氧腐蚀速率随温度的升高先增加后降低,一般在83℃左右达到极值;腐蚀速率随溶液矿化度的变化同样呈现此种规律,NaCl溶液达到10000mg/L时,腐蚀速率出现最大值。(3)在流体流动速率增大、搅拌加剧的情况下,腐蚀速率增加。(4)根据XRD、SEM分析结果,钢材腐蚀产物主要元素为Fe和O,主要成分包括γ-Fe O(OH)、β-Fe O(OH)、Fe3O4、α-Fe O(OH)等,腐蚀表面膜结构疏松不致密,对钢材基体的保护作用不大。通过室内实验对氧腐蚀防护措施有效性进行验证,结果表明:(1)典型注空气工况条件下,N80、P110、1Cr、3Cr钢材均发生严重腐蚀破坏,而13Cr、304、3016不锈钢腐蚀速率小于0.076mm/a。(2)利用润滑油脂对钢材表面进行处理,能够较大减缓钢材腐蚀,其防腐效果优于钝化处理。(3)pH升高可以起到降低腐蚀速率的作用。(4)缓蚀剂能有效抑制管柱材料腐蚀,实验中1#和2#缓蚀剂复配后最高缓蚀率超过了90%。注空气工艺过程中,井下管柱面临着复杂、恶劣的腐蚀工况环境,遭受着严重的腐蚀破坏。实验研究发现,单一的防腐措施很难将腐蚀速率控制在行业标准内,因此需要多元措施联用,形成系统的防腐方案。
[Abstract]:As a creative new technology to improve oil recovery, air injection flooding technology has been paid more and more attention in recent years. However, due to the injection of high pressure air, the downhole pipe string is in a high oxygen partial pressure, high temperature, water or wet environment, thus suffered serious corrosion damage, affecting the normal production of oil fields. It can be seen from site construction experience that corrosion as an inevitable problem of air / air foam enhanced recovery technology seriously restricts the application and popularization of this technology. Therefore, the corrosion mechanism and corrosion law of underground pipe string were studied by means of weightlessness method, XRD analysis, EDS analysis and SEM analysis. The results show that: (1) the oxygen corrosion rate increases with the increase of pressure, even when the dissolved oxygen concentration is very low (6mg / L), the corrosion rate of N80P110 steel is higher than that of industry standard (0.076mm/a). (2) the oxygen corrosion rate increases first and then decreases with the increase of temperature. The corrosion rate of NaCl solution reaches the maximum value when the salinity of NaCl solution reaches 10000mg / L. (3) when the fluid flow rate increases and the stirring intensifies, the corrosion rate reaches the maximum value at about 83 鈩，

本文编号：2099234