Compared to the conventional reservoirs,the pore structure of shale reservoirs is more complex and heterogeneous.A new method is developed to analyze the capillary pressure curve in shale samples.In studying the mercury-injection curve of the shale samples from the Upper Triassic shale gas reservoir in the West Sichuan depression of China,the authors find that the mercury-injection curve can be divided into two classes,and they also demonstrate how to adopt polynomial segmentation fitting to calculate the fractal dimension.After the characteristic of each segment is analyzed,they find that only a short segment with reasonable fractal dimension can describe the real distribution of pores.This proves that the capillary pressure curve can only reflect the distribution of the pore whose radius is >150 nm.%通过分形理论利用毛管压力曲线分析页岩储层的孔隙分布特征，研究储层内部的复杂孔隙结构。根据四川盆地上三叠统页岩储层样品的实测毛管压力曲线，结合前人的研究成果，总结出2类页岩储层毛管压力曲线；分段拟合计算分形维数后，发现压汞曲线只有部分段的分形维数在合理范围内。说明利用分形维数研究页岩储层孔径分布时，要对曲线进行分段拟合。此外，证明了毛管压力曲线能够反映孔径＞150 nm的中孔的孔隙半径分布。
展开▼
