Abstract
The inner structure of sedimentary rocks is studied as a system of interconnected pores. A regular cubic network is considered for the pores and the channels connecting them, with the latter being randomly open or closed. The problem of whether or not there is a hydraulic connection between two parallel faces of a cubic rock sample, depending upon the ratio of open edges to all the possible edges, is studied. Recursive solution for the described random network problem is given. The recursive solution in two dimensions is simulated on the computer as the simplest three-dimensional case.
Analysis of the probability of distributions gives a vivid, quantitative picture about the role of pore connection in hydraulic movement. As a rule of thumb for rocks with the above cubic structure, this role can be described as follows: if only 1/4 of the channels are open, the rocks are not permeable, but if 1/2 of the channels are open, the rocks are permeable.