【作者】 张学佳；

【导师】 王宝辉；

【作者基本信息】 大庆石油学院 ， 化学工艺， 2008， 硕士

【摘要】 三元复合驱(ASP)作为一种既经济又有效率的强化采油技术被各大油田广泛采用,已成为油田产量接替的主要措施。随着ASP驱油技术的扩大化应用,三元注入介质碱、表面活性剂、聚合物及其混合物在运输、配制、存储、注入过程中可能发生意外泄漏事件。所以在大力推广ASP采油技术的同时,会带来相应的环境问题,有必要对ASP化学剂的环境行为和危害性研究和评价,为下一步ASP大规模推广应用提供可靠的后备技术保证。本文通过检测大庆油田ASP中化学剂组成和含量以及ASP注入液和采出液化学成分,根据国内外现有的标准和环境评价方法,确定出ASP对环境影响的主要特征污染物有碱(氢氧化钠)、表面活性剂(直链烷基苯磺酸盐、未磺化油)及聚丙烯酰胺(丙烯酰胺)。并详细分析了ASP化学剂意外泄漏后特征污染物对生态环境所造成的影响及危害,总结出ASP中碱和未磺化油会对生态环境造成巨大的危害,且危害呈现持久和难处理的特点;直链烷基苯磺酸盐浓度是考察其环境危害性的关键因子,当浓度小于一定值时,其对环境是有利的,但随着浓度的升高其毒性增强;聚丙烯酰胺本身对动植物是无毒性的,对环境影响也很小,但是其降解产物丙烯酰胺会给人类和环境带来很大的危害。本文着重研究了ASP化学剂意外泄漏后在土壤中的环境行为。通过现场取样和室内土柱模拟实验,模拟了单元污染物(NaOH、LAS、PAM)和三元污染物在不同土壤(黑土、黄土、盐碱土)中的自然迁移和模拟降雨情况下的迁移行为,考查了不同时间、不同污染物数量对迁移情况的影响,对比分析得出污染物在土壤中的垂向迁移规律。一般情况下,ASP化学剂意外泄漏后,一段时间内其特征污染物NaOH在土壤中的迁移距离不会超过15cm、LAS迁移距离不会超过20cm、PAM迁移距离不会超过15cm。并且还通过室内实验研究了PAM和LAS在环境(土壤、水体)中的吸附和降解行为,LAS在环境中降解速度较快,土壤对PAM有很强的吸附力,一旦吸附很难再解吸下来。经过对三元复合驱中特征污染物在土壤中环境行为的全面分析,发现意外泄漏的特征污染物基本停留在土壤表层,即使在降雨、地表聚集着大量污染物的情况下,也不会影响到大庆地下水。通过对ASP化学剂中特征污染物环境危害性及环境行为的研究,总结出其在土壤中环境行为特性,对实现石油工业高效生产与环境保护并进,减少对环境的污染,保护人类生态环境具有深远意义。更多还原

【Abstract】 Alkali-surfactant-polymer(ASP) compound flooding is widely used in oilfields and plays a very important role in oil recovery.With the ASP flooding expanded application,alkali,surfactant,polymer and its compound in ASP is impossible avoid leaking to environment during the process of transport,preparation,storage and injection.Therefore,the widely ASP flooding application will bring the corresponding environmental problems.It is necessary to study and evaluate the pollutants environmental behaviors and impacts of ASP chemicals to provide the reliable technology guarantee for the next ASP large-scale application.In this paper,according to the existing domestic and overseas environmental standards and evaluation methods,the main environmental particular pollutants in ASP are identified as alkali(sodium hydroxide),surfactant(linear alkylbenzene sulfonates,unsulphonic oil) and polyacrylamide(acrylamide) by detecting the chemical compositions and contents of ASP chemicals,injection and flooding produced water in daqing oilfield.And the impact of main environmental particular pollutants in ASP on environment for accident of release are analyzed in detail.The alkali and unsulphonic oil in ASP can cause enormous harm to ecological environment and the harm show lasting and intractable features.The concentration of linear alkylbenzene sulfonates(LAS) is the key factor to measure its harm to the environment,when the concentration is less than a certain value,it is good to environment,but toxic enhanced with the increase of concentration.The polyacrylamide(PAM) is less environmental contamination and non-toxic to plants and animals,but its degradation product acrylamide(AM) can cause great harm to human beings and environment.Environmental behaviors of ASP chemicals in soil for accident of release is completed studied in this paper.The migration of unit pollutant(alkali,LAS,PAM)and ternary pollutants in different soils(black soil,loess soil,saline alkali soil) under natural and simulated rainfall conditions are studied by onsite sampling and soil column experiments in laboratory.Effect of time and amount on the law of pollutants transferring in soil is investigated and the vertical migration law in soil is found.Under normal circumstances,when ASP chemicals accident happened,the migration distance of alkali pollutants in soil does not exceed 15cm,migration distance of LAS not exceed 20cm,migration distance of PAM not exceed 15cm in period of time.Moreover,the adsorption and degradation of PAM and LAS on the environment are also studied in laboratory.LAS degradate fast in the environment.PAM has a high adsorptive affinity on soil and it is very difficult desorbed.Based on the comprehensive analysis of environmental behaviors of ASP pollutants in soil,we can conclude that most particular pollutants in ASP rested soil surface in the leaking accident.Even much more pollutants on soil surface under rainfall conditions,it will not affect groundwater in daqing.The study of the behavior and impact of ASP pollutants in soil will provide insight into the character of environmental behaviors,which is of great significance for improving the oil industry productivity together with eco-environmental protection and reducing environmental pollution.更多还原