分形几何方法在复杂裂缝系统描述中的应用

Application of fractal geometry on the description of complex fracture systems

探讨了利用分形几何方法来定量描述复杂非系统裂缝的兮市.以高精度岩心扫描图像为基础,首先计算了当心复杂裂缝的分数维D值,然后进一步兮析了这些复杂裂缝的分数维与裂缝的面密度、孔隙度、渗透率之间的关系,发现复杂裂缝系统的面密度、孔隙度、渗透率随裂缝分数维D值呈指数函数增大的规律.裂缝的分数维D值不仅可以表征复杂裂缝系统的发育程度,而且还能够表征复杂裂缝系统对致密低渗透储集层的储集性能和渗流能力的贡献.

Fractal geometry method was discussed to quantify the fracture distribution characteristic of non - systematic fractures. Based on the high resolution scanning photos of fractures in core, fractal dimension D of core fractures was calculated and then analysis were made on the relationship between the fractal dimension and areal density, porosity and permeability of these complex fractures. It is found that the areal density, porosity and permeability increase exponentially with the increasing of fractal dimension D. The fractal dimension D of fractures can characterize not only the development of fractures but also the contribution which is made by complex fracture system to the reservoir property and percolation ability of tight low - permeability reservoirs.