Pattern Structure and Properties of Invasion Percolation in Porous Media

The percolation clusters with varying occupy probability are constructed.Invasion percolation(IP)in percolation cluster is investigated by means of IP alporithm without trapping.The pattern constructions of IP in percolation clusters are obviously different from that of visocous fingering(VF) in percolation clusters.The fractal dimension Df of IP increases with increasing the percolation probability P.The geometry and the topology of the porous media have strong effects on the pattern structure of IP.For large M(the node numbers occupied by the injected fluid),the rescaled value is Rg/M^1/Df,which asymptotically approaches a constant value,and Rg is the gyration radius of IP cluster,Moreover,the chemical dimension Dl and the shortest path exponent dmin are obtained.