Description of coal reservoir heterogeneity under different lithotypes based on X-CT technology

In order to further explore the coupling relationship between the lithotypes and the coal reservoir pore-fracture system, superficial characteristics the vert ical heterogeneity in Hancheng Mining Area, coal samples of different lithotypes in Hancheng mining area were selected. Using the X ray tomography, the form and spa ce distribution of pore-fracture system, matrix and mineral of coal in Hancheng area were simulated and reconstructed, and the three-dimensional reconstruction model was established, finally the fine characterization of the three dimensional visualization of different lithotypes was realized. The results show that the series isorank coal of Hancheng have the characteristics of that the different of lithotypes have the different pore-fracture development degree, but the change of CT values were the same which the distribution were bimodal as a whole. Compared to the semibright coal, semidull coal and dull coal, the bright coal pore-fracture system development degree was the highest, the heterogeneity of pore distribution was the strongest, and the pore-fracture system connectivity was the best. Furthermore, from the bright coal to th e dull coal, the development degree and connectivity of the pores are gradually becoming worse, the flling degree of the mineral and the content of the micorpores are i ncreasing.