【作者】 孙景伦；

【导师】 沈强；

【作者基本信息】 山东大学 ， 物理化学， 2008， 硕士

【摘要】 碱/表面活性剂/聚合物(ASP)三元复合驱油技术，主要是利用化学剂之间的协同效应，既提高了驱油效率又增大了波及系数。目前，大庆油田的三元复合驱油先导性矿场试验已取得了成功，并将逐步推广应用。在三元复合驱技术中，碱对提高原油采收率有明显的促进作用，并且还具有低成本和易操作等特点。但是碱的用量和种类的选择比较复杂，这主要是因为碱不但能与其他化学剂发生作用，而且与原油、地下水以及岩石均能发生反应。本文中，用相等当量的碳酸钠和氢氧化钠考察碱与原油的反应情况，并且将油酸、卟啉、蜡、乙酸乙酯和邻苯二甲酸二乙酯的混合酯加入到油相中来研究油水之间的界面反应。本论文共分五个部分：1、详细介绍了研究的背景和相关的研究成果。2、为了考察碱在复合驱油体系中的作用，将原油中的酸性组分分离、剖析，结果发现大庆原油中酸性组分主要包括直链羧酸二甲酸，芳香二甲酸和直链羧酸。3、大庆原油的地层温度约为45℃左右，粘度约为10．5 mPa·s。本文中，为了近可能地模拟地层条件，选用大庆脱气原油与煤油(无色，即去除被氧化的煤油组分)按照体积比1：1配制模拟油。根据原油中酸性组分的相对含量，在模拟油中加入油酸和混合酯来考察不同的极性物质对碱耗的影响。结果表明，碳酸钠与原油中的酸性组分反应较慢并且只能部分反应，而氢氧化钠则快速和完全地与其反应。而且由于盐效应的影响，碳酸钠降低界面张力的能力比氢氧化钠更强。4、主要介绍了大庆原油中蜡的性质。首先提取从大庆原油中提取了蜡晶，并配制了环己烷与蜡晶的模拟油溶液，测量其与碱的界面张力情况，发现弱碱碳酸钠降低油水界面张力的能力比氢氧化钠强，并总结出油相中蜡晶含量越高，界面张力越低的规律。5、随着三元复合驱技术的推广使用，采出液的处理变得越来越困难，这主要是因为三元复合驱采出液中含有的表面活性剂、聚合物和碱有助于油包水和水包油型乳状液的形成。根据液膜破裂和消失的时间，建立和测量了乳状液破乳的实验参数，同时考察了碱、表面活性剂和聚合物对乳状液液膜强度的影响。更多还原

【Abstract】 For the ASP （alkaline-surfactant-polymer） flooding, the cooperation of the three displacement agents not only upraises the washing efficiency of crude oil but also enlarges the sweeping volume of flooding phase, therefore, the recovery percentage of crude oil grows up considerably. Nowadays, the technology of ASP flooding has been successfully explored in the precursor experiments in Daqing oilfield, which will be spread for the in-situ application in near future.In ASP flooding systems, the alkaline agents have an appeal for enhanced oil recovery because of their low cost and favorable performance. Nevertheless, the choice and dosage of alkaline agents has been remaining complex, due to their interactions with other species in the chemical slug but also with the crude oil, reservoir water, and/or reservoir rock. Therein the interaction between alkaline agent and crude oil is necessary and useful, forming surface active species for oil displacement. In this thesis, sodium carbonate （Na₂CO₃） and sodium hydroxide （NaOH） was used as the alkaline chemicals, at the same Na₂O content, to investigate the oil/water interfacial reactions between the Daqing crude oil and the alkaline solutions. Moreover, oleic acid, porphyrin, wax or the mixture of ethyl acetate and phthalic acid diethyl ester were added into the oil phases, respectively, to facilitate the studies of the interfacial interactions and to compare the functional effectiveness of alkalis.All of the thesis works are divided into five parts. In chapter I, the research background was introduced, and the relative research papers were summaried. To investigate the functional effectiveness of an alkaline agent in ASP flooding system, the relative active-species should be extracted from the crude oil first. Then the methylation and the consequent characterization of the extracted acidic fractions were conducted. The main results in Chapter II showed that the acidic extracts from Daqing crude oil comprised of alkyl dimethyl acids, aromaticity dimethyl acids and alkyl acids.In this thesis, the oil phase used was the model oil, namely, the mixture （1:1, v/v） of the degassed crude oil and the commercial kerosene, possessing a viscosity of 10.5 mPa.S at 45°C to simulate the basic fluidity of the underground oil in Daqing oil field. By considering the relative content of extracts and the acidic number of crude oil, oleic acid, the mixture of ethyl acetate and phthalic acid diethyl ester were selected as the polar additives, respectively, to conduct the influence of different polar mixtures on alkaline consumption. The results Chapter III showed that: Na₂CO₃ reacted slowly and partly with the acid components in crude oil, while NaOH did it very fast and completely. Interestingly, Na₂CO₃ is better than NaOH in lowering the oil/water interfacial tension （IFT）, due to its buffer effect.Another basic parameter of the Daqing crude oil is the highly waxy. First, wax crystallization from crude oil was performed, then, the model oil of hexane and waxy extracts was used to measure the interfacial tension between the oil phase and an alkaline solution. The results in Chapter IV indicated that latent alkali of Na₂CO₃ was better than NaOH in lowering the oil/solution interface tension. Interestingly, it was found that the higher the waxy content, or the waxy crystallites, in oil phase, the lower value of the interface tension.Generally, the produced liquids after chemical flooding are very difficult to demulsify. The presence of surfactant, polymer and/or alkali in produced solutions helps the formation of W/O or O/W emulsion after ASP flooding. First, the experimental apparatus was set up and shown in chapter V. Then, the relative parameters for emulsion destruction were measured, basing on the rupturing （or, vanishing） times of the liquid films. The functional effectiveness of alkalis was presented, at the mean time, the effects of surfactant and polymer on the intensity of liquid film were also discussed.更多还原