一种处理油田压裂返排液的新方法研究

发布时间：2018-01-09 06:22

本文关键词：一种处理油田压裂返排液的新方法研究　出处：《沈阳工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：压裂作业是油气田增产的一项重要措施，同时还可以改善油气层的导流能力，因此被各大油田普遍采用，在作业结束后产生大量的废液返回至地面，成为油田当前水体的主要污染源之一。目前国内外处理压裂液返排液的方法有固化法、微电解法、生化法、超临界水氧化法等方法，每种方法单独使用对废水处理都不彻底。与其他几种处理方法相比较，微电解法是一种既经济又高效的处理方法，但微电解法也存在自身的不足，如反应过程中铁表面容易钝化，铁碳容易板结，从而降低了处理效率。为了解决以上问题，本文提出了一套联合处理工艺即：氧化破胶-空化撞击流反应器结合微电解法-Fenton氧化法。本文把吉林油田1#压裂液返排液作为研究对象，进行了以下几方面研究：（1）联合工艺处理压裂液返排液机理研究及水样污染物分析。由水样污染物分析可知，，压裂液返排液的CODCr值高达8910mg/L，固体悬浮物高达236mg/L，含油量高，粘度是水的3倍。（2）氧化剂筛选。研究发现，在同等条件下过硫酸铵破胶效果最好，处理后废水澄清透明，CODCr去除率可达34%。（3）微电解反应条件实验研究。确定了微电解最佳反应条件为：初始pH=2、铁碳质量比为4:1、t=120min。在此条件下CODCr去除率为36.5%。（4））空化撞击流结合电解法处理废水实验研究。研究结果显示，在上述反应条件一样的情况下，改用空化撞击流反应器，在t=90min时，CODCr的去除率已达到75.8%。（5）Fenton氧化的最优反应条件研究。确定的最优反应条件为：30%双氧水加入浓度为2mL/300mL，pH=3.0，t=60min时。在此条件下CODCr降低率为16.2%。研究表明该联合工艺对压裂液返排液具有很好的处理效果，经处理后废水总CODCr去除率达到92%。空化撞击流反应器结合微电解法二者具有很好的协同作用，与传统微电解相比，此方法不但使反应时间缩短25%，而且还使CODCr降低率提高5.3%。此外，铁碳微电解后废水中含有Fe2+离子，在后续的Fenton氧化中起催化作用，不必再加入含铁盐，可以节约成本。因此该联合工艺为处理压裂液返排液提供了一种既经济又高效的新方法，具有很广阔的应用前景，在不久的将来必将会给社会带来良好的经济效益。
[Abstract]:Fracturing is an important measure to increase production of oil and gas field, and it can also improve the flow conductivity of oil and gas reservoir, so it is widely used in various oil fields, and a large amount of waste liquid is returned to the surface after the operation. It has become one of the main sources of water pollution in oil fields. At present, the methods of treating fracturing fluid back and forth at home and abroad include solidification, microelectrolysis, biochemistry, supercritical water oxidation and so on. Compared with other treatment methods, micro-electrolysis is an economical and efficient treatment method, but micro-electrolysis has its own shortcomings. For example, the surface of iron is easily passivated and the iron and carbon are easily bound in the reaction process, thus reducing the treatment efficiency. In order to solve the above problems. In this paper, a combined treatment process is proposed, that is, oxidation of gel-breaking and cavitation impingement reactor combined with micro-electrolysis and Fenton oxidation. In this paper, the oil field of Jilin oil field fracturing fluid back as the research object, carried out the following aspects of research: From the analysis of water sample pollutants, the CODCr value of fracturing fluid is up to 8910 mg / L. Solid suspensions are as high as 236 mg / L, high in oil and three times as high in viscosity as water. The results showed that ammonium persulfate had the best gel breaking effect under the same conditions, and the removal rate of CODCr was 34. The optimum reaction conditions were determined as follows: initial pH 2, iron-carbon ratio 4: 1. Under this condition, the CODCr removal rate was 36.5%. Experimental study on cavitation impinging current combined with electrolysis for wastewater treatment. The results show that under the same reaction conditions above, cavitation impinging flow reactor is changed to cavitation impinging flow reactor for 90 min. The removal rate of CODCr has reached 75.8%. The optimum reaction conditions of Fenton oxidation were determined as follows: the concentration of 20% hydrogen peroxide was 2 mL / 300 mL ~ (-1) pH ~ (3 +). The reduction rate of CODCr was 16. 2% at 60 min. The study shows that the combined process has a good treatment effect on fracturing fluid reflux. The total CODCr removal rate of treated wastewater is 92%. Cavitation impinging flow reactor and micro-electrolysis have good synergistic effect compared with traditional micro-electrolysis. This method not only shortens the reaction time by 25%, but also increases the CODCr reduction rate by 5.3%. In addition, there is Fe2 ion in the wastewater after iron-carbon micro-electrolysis. In the subsequent oxidation of Fenton, it can save the cost without adding iron salt, so the combined process provides a new economical and efficient method for the treatment of fracturing fluid reflux. It will bring good economic benefits to the society in the near future.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X741

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