高孔隙度砂岩储层中砂体成因类型、孔隙结构与渗透率的关系

在高孔隙度砂岩储层中，由于孔隙类型多样化、结构复杂、孔隙度与渗透率的相关性较差，给渗透率的预测带来较大的困难。从沉积学入手，利用砂体成因分析和储层各种微观测试手段（铸体薄片、压汞分析和显微图象分析等），结合数理统计方法，找出砂体成因类型、孔隙结构和渗透率之间的对应关系。砂体沉积时，沉积环境（水动力条件）控制了砂岩中孔喉等效半径分布规律。其中，粗喉（１０～６０μｍ）体积分数是决定高孔隙度砂岩储层渗透率的关键所在。根据砂体成因类型可以预测其孔喉等效半径和相应渗透率值的经验数据

RELATIONSHIPS OF GENETIC TYPES OF SAND BODIES, PORE TEXTURES AND PERMEABILITY IN THE SANDSTONE RESERVOIR WITH HIGH POROSITY

Various pore types, complex pore textures, and poor corelationship between porosity and permeability make it difficult to predict the permeability in the sandstone reservoir with high porosity. We have found the relationships between genetic types, pore textures and permeability in the sandstone by means of sand body genetic analysis, microscopic analysis of the sandstone reservoir (e. g. dyed epoxy resin cast sections, pressured mercury analysis and microimage analysis) and geo statistics. While the sand bodies were depositing,the pore texture and the distribution of pore radius in the sandstone were controlled by the sedimentary environments (the dynamic condition of water agents). Of all the variaties, the percentage of relative volume of the throat (10-60 microns) is the most crucial one that makes the sandstone have a certain permeability. Finally, the empirical data are given to predict the pore radius variation and the permeability the sandstones should have according to the genetic types of sandstones in the area.