废弃油基钻井液无害化处理

发布时间：2018-04-04 04:10

  本文选题：废弃油基钻井液　切入点：无害化处理　出处：《东北石油大学》2015年硕士论文

【摘要】：随着我国油气勘探开发技术的不断发展,油基钻井液技术也逐渐发展,同时钻井过程中产生的废液数量也在不断增加。废弃油基钻井液中含有大量石油类以及重金属元素等,对环境产生的巨大的影响。目前,针对废弃油基钻井液处理技术并不完善,且存在明显缺点和局限性。如何将废弃油基钻井液进行合理化处理也成为了阻碍我国钻井技术发展的一大难题。本文从油基钻井液的组成、性质以及功能三方面对其进行介绍,然后列举一些常用的处理方法和国内外最新研究成果;再而,对废弃油基钻井液的浸出液进行了分析测定,确定了pH、COD、油类以及重金属等污染因子的含量;然后分析了废弃油基钻井液以及固液分离产生的泥渣的组成,对固液分离产出液进行了化学破乳试验,确定了最佳破乳条件。最后对固液分离产生的泥渣和固液分离产出液破乳后产生的废水进行了超临界水氧化试验。试验分析结果表明:废弃油基钻井液中含有但并未超过标准的金属元素有镍、六价铬、总铬、镉、铜、铅、锌、铍;不含有汞、银、硒、砷等污染物;晶石粉(BaSO4)是钻井液的重要组成成分,因而钻井液中含有钡元素的含量达到允许排放的限值。虽然pH处于正常范围,但是其他的石油类、化学需氧量COD均超出标准,分析结果显示石油类高达34776 mg/L,超标3477.6倍,COD高达198765 mg/L,超标1325.1倍。因此可知废弃油基钻井为危险废弃物,若不经过严格的处理就排放到环境中,将对环境产生极大的危害。对化学破乳法回收油进行试验研究,其最佳破乳条件:破乳剂SP加剂量40 mg/L,PAC加剂量800 mg/L,PAM加剂量8 mg/L,破乳时间60 min,破乳温度65℃,离心转速3500 r/min,离心时间为4 min。在破乳最佳条件下,油回收率可达90.03%,破乳所产生的废水COD为4213 mg/L,超出《污水综合排放标准》(GB8978-1996)二级标准限值,需要进行再次处理。采用超临界水氧化法处理固液分离所得泥渣和固液分离产出液破乳所得废水,其最佳反应条件:反应温度为450℃,反应压力为26 MPa,停留时间为10 min,氧化剂过氧比为4,初始COD浓度为2400 mg/L,p H为10。在最佳反应条件下,反应物COD的去除率可达97%,处理后泥渣的含油量为355 mg/kg,低于《农用污泥中污染物控制标准》(GB4284-84)限值。废水的COD含量为68 mg/L,低于《污水综合排放标准》(GB8978-1996)二级标准限值。
[Abstract]:With the development of oil and gas exploration and development technology in China, oil based drilling fluid technology is developing gradually, and the amount of waste fluid produced in drilling process is also increasing.The waste oil base drilling fluid contains a large amount of petroleum and heavy metal elements, which has a great impact on the environment.At present, the waste oil-based drilling fluid treatment technology is not perfect, and there are obvious shortcomings and limitations.How to rationalize the waste oil-based drilling fluid has also become a major problem hindering the development of drilling technology in China.In this paper, the composition, properties and functions of oil-based drilling fluid are introduced, then some common treatment methods and the latest research results at home and abroad are listed, and the leaching fluid of waste oil-based drilling fluid is analyzed and determined.The content of pollution factors such as pH = COD, oil and heavy metals were determined, and then the composition of waste oil-based drilling fluid and sludge produced by solid-liquid separation was analyzed, and the chemical demulsification test was carried out to determine the optimum demulsification conditions.Finally, the supercritical water oxidation test was carried out on the sludge produced by solid-liquid separation and the waste water produced by solid-liquid separation after demulsification.The results show that the metal elements in the waste oil base drilling fluid are nickel, hexavalent chromium, total chromium, cadmium, copper, lead, zinc, beryllium, mercury, silver, selenium, arsenic and other pollutants, and the metal elements in the waste oil base drilling fluid are nickel, hexavalent chromium, total chromium, cadmium, copper, lead, zinc, beryllium, etc.BaSO4) is an important component of drilling fluid, so the content of barium in drilling fluid reaches the allowable emission limit.Although the pH is in the normal range, the chemical oxygen demand (COD) of other petroleum is above the standard. The results show that the oil is up to 34776 mg / L, 3477.6 times higher than the standard, 198765 mg / L, 1325.1 times higher than the standard.Therefore, waste oil-based drilling is a hazardous waste, if it is discharged into the environment without strict treatment, it will cause great harm to the environment.The optimum demulsifying conditions were as follows: the demulsifying agent SP plus 40 mg / L PAC plus 800 mg / L PAM + 8 mg / L, the demulsifying time was 60 min, the demulsifying temperature was 65 鈩，

本文编号：1708309