低孔低渗储集层岩石物理分类方法的讨论

为了在储集层孔隙结构和岩石物理特征基本相同的情况下建立测井解释岩电参数模型，需要按岩石物理特征对储集层进行分类。通过实际资料和理论分析，对比地层流动带指数与储集层品质指数两种宏观物性参数的差异，研究储集层岩石物理分类的有效方法和反映微观孔隙结构变化的特征参数。利用两种指数对松辽盆地大情字井地区和鄂尔多斯盆地姬塬地区典型低孔低渗储集层60块岩心的压汞实验资料进行了分类，结果表明，按照储集层品质指数对储集层进行分类能更准确地反映储集层的孔隙结构和岩石物理特征。理论分析亦证明，储集层品质指数与孔隙结构之间呈单调函数关系，而地层流动带指数与储集层孔隙结构之间并不是简单的单调函数关系，储集层品质指数比地层流动带指数能更准确地反映储集层孔隙结构和岩石物理性质的变化。图6表1参14

A method for petrophysical classification of low porosity and low permeability reservoirs

In order to establish a rock electrical parameters model under the condition that pore structures and petrophysical characteristics are identical, it is necessary to classify reservoirs according to petrophysical characteristics. The disparity of two macroscopic parameters, flow zone index and reservoir quality index, is contrasted by analyzing actual data, and an effective method of classifying reservoirs is proposed based on petrophysical parameters and microscopic pore structures. The mercury injection experimental data of sixty rock samples of typical low porosity and low permeability reservoirs in the Daqingzijing (Songliao basin) and Jiyuan (Ordos basin) areas are classified based on these two indexes. The result shows that the reservoir classification by reservoir quality index is more reasonable. The theoretical analysis also demonstrates that reservoir quality index is the monotone function of pore structure while flow zone index is not. Compared with flow zone index, reservoir quality index can reflect the variation of reservoir pore structures and petrophysical properties more exactly.