电子显微镜在油田开发中有着广泛地应用,能够解决普通显微镜不能解决的问题,并且能观察储层的储集空间和喉道类型,对油气的储运有更直观地了解.因此本文在前人对该区域宏观地质条件认识比较全面的基础上,以油田的生产现状为立足点,运用扫描电镜、铸体薄片,高压压汞等实验手段来划分研究区储层微观孔隙结构的类型.然后选取每个类型的代表样品来做真实砂岩微观模型水驱油实验,一方面验证前面储层微观孔隙结构分类是否正确,另一方面研究微观孔隙结构特征与驱油效率的相关性究竟如何.结果表明,研究区储层的储集空间主要是溶蚀孔和粒间孔,喉道类型以片状喉道为主.按照高压压汞曲线形态将研究区储层分为:Ⅰ、Ⅱ、Ⅲ和Ⅳ类.由于Ⅳ类属于无效储层,本文只讨论前三类,这三类不同孔隙结构的储层对应的驱油效率和驱油路径差异比较大.综合得之,孔喉半径是比孔隙度和渗透率更有效的参数去反映与驱油效率之间关系,应用孔隙结构特征来划分储层类型并研究与驱油效率的关系更科学.并且通过水驱油实验,作者发现在注水开发时,孔隙连通性不是越大越好,而是存在一个最佳值.%The microstructures of the chang-6 reservoir in Ban Qiao?He Shui area was studied by scanning electron microscope ( SEM) , high pressure Hg injection and water flooding test. The accuracy of the previous classification of the pore structures of chang?6 reservoir was verified and the relationship between the pore characteristics and the oil displacement efficiency was analyzed. The results show that the pores inside the chang?6 reservoir are mainly dissolution pores and intergranular pores while the throat is mainly flake throat. The reservoir was classified into 4 types according to the high pressure Hg injection test results:Ⅰ,Ⅱ,ⅢandⅣ. The oil displacement efficiency and oil displacement path are various for different types of reservoirs. It can be concluded that the pore throat radius is more closely related with the oil displacement efficiency than porosity and permeability parameters and it is more scientific to characterize the reservoirs according to the pore structure features. In addition, an optimum value of the pore connectivity is existed corresponding to the maximum displacement efficiency.
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