非均相复合体系PPG驱替残余油机理研究

发布时间：2018-03-05 12:26

本文选题：非均相复合体系　切入点：稳定性　出处：《中国石油大学(华东)》2015年硕士论文　论文类型：学位论文

【摘要】：聚合物驱近年来广泛应用于我国各大油田,技术已经相当成熟,但聚合物驱后油层中仍有大量残余油分布,有待于采取进一步措施进行挖潜。因此采用由聚合物和PPG复配而成的非均相复合驱油体系,探讨了该体系的稳定性与流变性能,评价了其驱油效果,并系统研究了PPG驱替残余油的机理。采用流变法、称重法及筛网过滤法分别研究了PPG的流变性能、膨胀性能及封堵性能,以此为依据筛选出合适的样品,并研究了该样品的耐温、耐盐及耐酸碱性。高弹性PPG颗粒易破碎而低弹性PPG颗粒不能对筛网进行有效封堵,综合考虑膨胀倍数及弹性,选择中弹性的2#PPG作为研究对象,且该PPG具有一定的的耐温、耐盐及耐酸碱性。将筛选出的PPG和聚合物溶液复配为非均相复合体系,利用稳定性分析仪和流变仪分别研究了其稳定性及流变性能。非均相复合体系稳定性随聚合物浓度增大而增强,随PPG浓度增加而减弱。非均相复合体系最佳配方为:1000mg/L聚合物浓度+1000mg/L PPG。随温度的升高非均相复合体系的储能模量减小;随各盐离子浓度的升高而降低;随pH的升高有所降低,但总体变化不大。利用化学驱动态模拟实验装置评价了非均相复合体系的驱油效果。PPG与聚合物溶液复配驱油不仅能降低聚合物用量,还能在聚合物驱基础上有效提高采收率。PPG可有效封堵高渗层,对于聚合物驱后的均质或非均质地层均可提高采收率。利用可视化微观驱油手段研究了PPG在多孔介质中的运移规律,并揭示了PPG驱替残余油的机理。PPG在多孔介质中运移方式多样化,其中对降低残余油饱和度起主要作用的有变形通过、隔断通过及堵塞,粘附及直接通过则起次要作用。聚合物驱后油层中残余油的存在形式主要有膜状、簇状、柱状及盲端,非均相复合体系PPG选择性封堵机理及颗粒弹性变形驱油机理可有效减少膜状、簇状及柱状残余油,对盲端驱替效果不佳。
[Abstract]:Polymer flooding has been widely used in various oil fields in China in recent years. The technology has been quite mature, but there are still a large number of residual oil distribution in the reservoir after polymer flooding. Therefore, the heterogeneous composite oil displacement system composed of polymer and PPG is used to study the stability and rheological properties of the system, and the oil displacement effect is evaluated. The rheological properties, swelling properties and plugging properties of PPG were studied by rheological method, weighing method and sieve filtration method respectively. The temperature tolerance, salt tolerance and acid and alkali resistance of the sample were studied. The high elastic PPG particles were easily broken, but the low elastic PPG particles could not effectively block the sieve mesh. Considering the expansion ratio and elasticity, the medium elastic 2 #PPG was selected as the research object. The PPG has a certain temperature tolerance, salt resistance and acid and alkali resistance. The selected PPG and polymer solution are mixed into heterogeneous composite system. The stability and rheological properties of heterogeneous composite system were studied by using stability analyzer and rheometer. The stability of heterogeneous composite system increased with the increase of polymer concentration. The optimal formulation of heterogeneous composite system is: 1: 1000mg / L polymer concentration 1000mg / L PPG. The storage modulus of heterogeneous composite system decreases with the increase of temperature, decreases with the increase of salt ion concentration, and decreases with the increase of pH. But the overall change is not obvious. The oil displacement effect of heterogeneous composite system. PPG and polymer solution combined flooding can not only reduce the amount of polymer, but also the dynamic simulation device of chemical flooding is used to evaluate the oil displacement effect of heterogeneous composite system. On the basis of polymer flooding, the oil recovery. PPG can effectively seal the high permeability layer. For homogeneous or heterogeneous formations after polymer flooding, oil recovery can be improved. The migration law of PPG in porous media is studied by means of visual microscopic oil displacement. The mechanism of PPG displacement of residual oil is revealed. The migration modes of PPG in porous media are diversified, among which the deformation passage, partition passage and blockage play a major role in reducing residual oil saturation. Adhesion and direct passage play a secondary role. The main forms of residual oil in polymer flooding are membrane, cluster, columnar and blind end. The selective plugging mechanism of PPG and the displacement mechanism of granular elastic deformation in heterogeneous composite system can effectively reduce film, cluster and columnar residual oil, which is not good for blind end displacement.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE357.46

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