Pore structure characteristics of weakly cemented sandstone with different buried depths in Shendong mining area

In order to study the pore structure characteristics of weakly cemented sandstones with different buried depths in Shendong mining area, four kinds of weakly cemented sandstones with different buried depths in Buertai coal mine are taken as the research objects.Four kinds of samples with different buried depth were tested by low field NMR.The T₂ spectrum characteristics, pore size distribution and pore throat distribution of weakly cemented sandstone with different buried depths are analyzed.The results show that there are differences in T₂ spectrum characteristics, pore size distribution and pore throat distribution of four weakly cemented sandstones with different buried depths (92.14-94.30 m, 118.40-120.69 m, 242.27-242.95 m, 317.86-320.33 m).The porosity of four weakly cemented sandstones with different buried depths are 39.180%, 36.132%, 44.782% and 19.732%, respectively.T₂ spectrum gradually changed from three peaks to two peaks, with good continuity (good pore connectivity).The pore size of weakly cemented sandstone can be divided into five types:micropore, small pore, medium pore, large pore and microfissure.The pore size is mainly small and medium-sized pore, followed by large pore.The pore throat radius of weakly cemented sandstone is mainly 0-0.10 μm, followed by 0.10-0.16 μm.The research results are helpful to further reveal the mechanism of water and sediment break in working face in western China.