储层渗透性与地层因素关系的实验研究与分析

本文对渤海湾盆地不同孔隙结构样品的孔、渗、核磁、岩电、压汞、X衍射及铸体薄片等配套岩石物理实验数据进行了综合分析,通过逐一考察同一套岩芯样品的地层因素与渗透率、压汞喉径均值、储层品质指数之间的实验关系,并分别与地层因素-孔隙度交绘图进行对比分析,发现储层渗透性与地层因素之间并非简单的单调函数关系,孔隙度相近但孔隙结构类型不同、渗透率差异明显的岩芯可以具有相近的地层因素,导电能力接近.在实验数据分析的基础上通过理论分析证明了这一实验关系的合理性,并指出孔隙度及导电能力相近的岩芯,其渗透率差异与喉径均值的平方比、孔隙曲折度及几何形态相关.

Experimental study on the relationship between reservoir permeability and its formation resistivity factor

It is very important to understand correctly the relation of formation permeability with the resistivity factor in order to improve the evaluation of low permeability reservoirs with strong heterogeneity by using electrical logging data. This paper made a comprehensive analysis of the assorted experimental data obtained from the Bohai Bay basin including porosity, permeability, NMR T₂ spectrum, rock resistivity, mercury injection, X-ray, casting thin sections and so on. For the same group of core samples, the relation of formation resistivity factor to permeability, average pore throat radius and reservoir quality index is further studied separately. Each result is compared to the relation of formation resistivity factor to porosity. It is found that the relation of formation permeability to its resistivity factor is not monotonic and that core samples with similar porosity but different pore structure quality and permeability can have close electrical conductivity. The reasonability of this phenomenon is further proved theoretically. It is also pointed out that the difference of permeability is related to square ratio of average pore throat, pore tortuosity and geometry for core samples with similar porosity and electrical conductivity.