Abstract: There is fractal property in pore space of reservoir rocks. The fractal dimension can be used to describe quantitatively the complexity of pore structures. According to principle of the fractal geometry, the fractal model for pore size distribution and capillary pressure curve is developed, and a correlation between the statistics and fractal parameters is derived. The fractal parameters of pore structure are estimated based on the capillary pressure data before and after waterflooding to investigate the effect of waterflooding on variation of pore structure. The results show that the pore structure becomes more complex and more heterogeneous after waterflooding.

Key words: rock, pore structure, fractal dimension, waterflooding, capillary pressure