Pore space characterization method of shale matrix formation based on superposed digital rock and pore-network model

Aiming at the characteristics that both the organic and inorganic pores are existing in the shale matrix, digital core and pore network model which could describe these two kinds of pores at the same time are constructed in this paper. Firstly, the inorganic pore digital core and organic pore digital core are constructed based on simulated annealing method and Markov Chain Monte Carlo method. Secondly, the two digital cores are superposed together according to certain algorithms, which includes the shale organic and inorganic pores information. Meanwhile, pore network models of these two digital cores are extracted respectively. And they are integrated into one pore network model, which could represent the dual pore information. Finally, based on these two platforms, the geometry topology structure properties, pore radius distribution and coordination number of a shale sample are analyzed. The simulated results match well with the experimental results, which verify the correctness of the construction method and numerical analysis methods.