Study of the Microstructural Characteristics of Low-Rank Coal under Different Degassing Pressures

Low-rank coal samples from the Xishanyao Formation in southern Junggar basin of Xinjiang were processed under different negative pressures order to examine microstructural characteristics low-rank reservoirs. The pore structures tested using scanning electron microscopy, low-temperature nitrogen adsorption–desorption, and water saturation centrifugal low-field NMR experiments. results showed that for study area, a high portion porosity surface area came micropores small pores; fractal dimension adsorption pores was divided into D1 structural D2, which microstructure complex. transverse relaxation times T2 test approximately 0.1~2.5, 10, greater than 100 ms; spectrum had basically three peak types. By combining microscopy nuclear magnetic resonance tests, it concluded connectivity reservoirs poor effective relatively low, may be unfavorable exploration development coalbed methane.