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气—水、油—水界面张力及砂岩润湿特性实验研究

发布时间:2018-09-01 15:23
【摘要】:我国能源结构长期以来以煤炭为主,石油供需存在矛盾,国内石油产量亟需提高。同时工业生产中大量燃烧化石能源产生的CO2温室效应问题也越来越引起人们的重视。利用CO2提高石油开采率以及有效封存工业排放的CO2是应对这些能源与环境问题的有效措施。通过把捕获的CO2注入到低产油田中提高石油采收率或者注入到地下咸水层中实现封存,可以直接而有效的达到温室气体减排目的。CO2注入到地层的过程中伴随着两相或多相流体在岩石孔隙中的流动。储层中流体之间以及岩石和流体之间的相互作用影响着流体在岩石孔隙内的分布、毛细管力的方向和大小,从而影响流体在岩心中的渗流特性。为了很好的预测储层咸水层封存CO2的能力,就必须测量储层温度、压力条件下的流体间界面张力以及岩石表面的润湿特性。因此,开展在储层条件下流体间的界面张力(IFT)和岩石的润湿特性实验研究,能够为提高石油采收率以及CO2长期安全封存提供非常重要的数据依据。本文以提高石油采收率和CO2地质封存为背景,开展了以下研究:应用轴对称滴形分析法测量了CO2-盐水和油-水之间的界面张力,并详细分析了界面张力与温度、压力、盐水浓度之间的关系,得到了实验温压范围内的关联式,为在实验温压范围内预测一定浓度下的CO2-盐水界面张力提供参考依据。通过坐滴法测量了盐水在气态、液态及超临界态CO2氛围内与Berea岩心的接触角,研究了温度、压力、组分以及CO2相态变化对岩心润湿特性的影响。实验结果表明,油-水之间的界面张力受压力的影响不显著,随温度的升高而增长;而CO2-盐水的界面张力随温度和盐水浓度的增大而增大,随压力的增大呈降低趋势,而且随盐水浓度呈线性增长趋势。另一方面,由于表面粗糙度程度和组分差异,不同Berea岩心的接触角随温度和压力呈现不同变化趋势。但是从整体特征来看,在超临界CO2氛围下岩心都呈现从亲水性向非亲水性转变的润湿特性变化。之后,应用最大球算法对CT扫描获得的Berea岩心图像进行处理,获得岩心的孔隙网络模型。将实验得到的界面张力和接触角数据作为孔隙网络两相渗流模型的输入参数,模拟了砂岩中油-水、气-水两相渗流过程,获得了相对渗透率和毛细管压力曲线,与前人文献中的实验结果吻合很好。证明了孔隙网络模型不仅可用于预测油-水两相渗流特性,也可运用在CO2-盐水渗流特性研究中,为今后预测咸水层封存CO2的能力提供技术指导。通过模拟结果发现,超临界态CO2在咸水层中能够获得更大的封存量。
[Abstract]:For a long time, the energy structure of our country is dominated by coal, there are contradictions between supply and demand of oil, and the domestic oil output needs to be improved. At the same time, the problem of CO2 Greenhouse Effect produced by burning fossil energy in industrial production has attracted more and more attention. Using CO2 to improve the oil production rate and effectively store the industrial emissions of CO2 is an effective measure to deal with these energy and environmental problems. By injecting the captured CO2 into a low-yield oil field to improve oil recovery or into an underground salt water layer, It can directly and effectively achieve the aim of greenhouse gas emission reduction. CO2 injection into the formation is accompanied by the flow of two-phase or multi-phase fluids in rock pores. The interaction between fluids in reservoirs and between rocks and fluids affects the distribution of fluids in rock pores and the direction and size of capillary forces, thus affecting the percolation characteristics of fluids in rock cores. In order to predict the CO2 ability of salt water reservoir, it is necessary to measure the reservoir temperature, interfluid interfacial tension under pressure and the wetting characteristics of rock surface. Therefore, the experimental study of interfacial tension (IFT) and wetting characteristics of rocks under reservoir conditions can provide a very important data basis for improving oil recovery and long-term safe storage of CO2. Under the background of improving oil recovery and CO2 geological seal, this paper has carried out the following research: the interfacial tension between CO2- brine and oil-water was measured by axisymmetric drop shape analysis, and the interfacial tension, temperature and pressure were analyzed in detail. The relationship between salt water concentration and the experimental temperature and pressure range is obtained, which provides a reference for predicting the interfacial tension of CO2- brine at a certain concentration in the range of experimental temperature and pressure. The contact angles of salt water with Berea cores in gaseous, liquid and supercritical CO2 atmosphere were measured by drop method. The effects of temperature, pressure, composition and CO2 phase state on the wetting characteristics of cores were studied. The experimental results show that the interfacial tension between oil and water is not significantly affected by pressure and increases with the increase of temperature, while the interfacial tension of CO2- brine increases with the increase of temperature and concentration of brine, and decreases with the increase of pressure. Moreover, the saltwater concentration increases linearly. On the other hand, due to the difference of surface roughness and composition, the contact angle of different Berea cores varies with temperature and pressure. However, the core changes from hydrophilicity to non-hydrophilicity in supercritical CO2 atmosphere. Then, the maximum sphere algorithm is used to process the Berea core image obtained by CT scan, and the pore network model of the core is obtained. Using the experimental data of interfacial tension and contact angle as input parameters of porous network two-phase seepage model, the oil-water, gas-water two-phase seepage process in sandstone is simulated, and the relative permeability and capillary pressure curves are obtained. It is in good agreement with the experimental results in previous literatures. It is proved that the pore network model can be used not only to predict the oil-water two-phase seepage characteristics, but also to study the percolation characteristics of CO2- brine, and to provide technical guidance for predicting the ability of storing CO2 in salt water layers in the future. The simulation results show that the supercritical state CO2 can obtain a larger storage capacity in the salt water layer.
【学位授予单位】:大连理工大学
【学位级别】:硕士
【学位授予年份】:2015
【分类号】:TE31

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2 孙亮;邱振;朱如凯;郭秋麟;;致密页岩油气赋存运移机理及应用模型[J];地质科技情报;2015年02期

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4 彭攀;宁正福;祁丽莎;何斌;赵华伟;牛腾飞;;致密储层孔隙结构研究方法概述[J];油气藏评价与开发;2014年01期

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