强碱三元对萨中二类油层驱油效果影响研究

发布时间：2018-04-09 02:40

本文选题：强碱三元体系　切入点：孔隙结构　出处：《东北石油大学》2017年硕士论文

【摘要】：我国绝大多数油田已进入高含水开发后期,随着主力油层注聚潜力的减小,尤其是高含水开采阶段,无论是经济指标,还是技术指标,都将变差。主力油层产量在逐年下降,各油田在做好提高主力油层采油技术的同时,加大了对孔渗性差的二类油层的开发力度,力保油田的可持续性发展。因此,研究三元复合体系在二类油层中的驱油效果对油田进一步开采具有重要的指导意义。本文以强碱三元复合体系和萨中二类油层为研究对象,通过静态浸泡实验及常规压汞实验研究了强碱三元复合体系对储层岩石的溶蚀作用其对孔隙结构的影响;利用扫描电镜法研究了强碱三元复合体系中聚合物分子形态的影响因素;通过流动性实验研究了强碱三元复合体系在二类油层中的注入能力;通过微观可视化驱油实验研究了强碱三元复合体系的微观驱油机理;通过双管并联实验研究了副段塞粘度对驱油效果的影响及不同渗透率级差下强碱三元复合体系的驱油效果。结果表明:随着碱浓度的增大,强碱三元复合体系对储层的溶蚀作用增强;剪切作用对聚合物分子线团尺寸有影响,剪切后聚合物分子链之间的相互缠绕作用减弱,空间网状结构被破坏;强碱三元复合体系主要是通过降低界面张力来提高残余油启动能力,通过乳化作用使残余油以油滴或油丝的形式运移;在非均质双管并联岩心中,通过适当降低副段塞粘度可提高驱油效果,渗透率级差越大,驱油效果越差。
[Abstract]:Most oil fields in China have entered the late stage of high water cut development. With the decrease of the potential of polymer injection in the main reservoirs, especially in the stage of high water cut production, both economic and technical indicators will become worse.The production of the main reservoir is decreasing year by year. While improving the oil production technology of the main reservoir, the development of the second class reservoir with poor porosity and permeability has been increased, and the sustainable development of the oil field has been guaranteed.Therefore, it is of great significance to study the flooding effect of ASP system in the second class reservoir.In this paper, the influence of the dissolution of strong alkali ternary system on the pore structure of reservoir rock was studied by static immersion test and conventional mercury injection experiment, taking the strong alkali ternary composite system and the second class oil layer of Sazhong as the research objects.The influencing factors of polymer molecular morphology in strong alkali ternary system were studied by scanning electron microscope, and the injection ability of strong alkali ternary composite system in the second class oil layer was studied by fluidity experiment.The microcosmic oil displacement mechanism of strong alkali ternary composite system was studied by microscopic visualization oil displacement experiment, and the effect of the viscosity of secondary slug on oil displacement effect and the oil displacement effect of strong alkali ternary compound system under different permeability levels were studied by double pipe parallel experiment.The results show that with the increase of alkali concentration, the dissolution of the reservoir is enhanced by the strong alkali ternary composite system, the size of polymer molecular coils is affected by shearing, and the intertwining of polymer molecular chains is weakened after shearing.The space network structure was destroyed, the strong alkali ternary composite system mainly improved the starting ability of residual oil by reducing the interfacial tension, and the residual oil was transported in the form of oil droplets or oil wires through emulsification.The oil displacement effect can be improved by properly reducing the viscosity of the secondary slug, and the greater the permeability difference, the worse the displacement effect.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE357.46

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