Experimental study on the law of transitional gas flow in porous media

Abstract There are many nanoscale pores in deep low permeability coal seams. The flow of coalbed methane (gas) belongs to the gas porous media with medium and high Knudsen numbers. Its mechanism is one key unsolved scientific problems. In order explore transport law nanopores coal, a model based on microscopic boundary restriction was adopted describe law, its rationality verified by experimental data. Field Emission Scanning Electron Microscope used scan customized anodized aluminum membrane. Then, Maximally Stable Extremal Regions (MSER) algorithm MATLAB binarization were employed quantify pore structure parameters (equivalent size porosity) membrane pores. Finally, PMI micro-flow tester carry out different rarefied degree penetration experiments through membranes, verified. results show that method more accurate characterize sample whose theoretical sizes 20–35 nm, while MSER characterizes samples 110–150 nm 200–300 accurately. other words, for characterizing mesopores, macropores. have important reference value extraction nanopore media. Compared traditional model, considering this paper closer results. Moreover, it suitable describing multiscale nanopores. study provided guiding significance ascertaining migration seam, improving prediction accuracy taking effective measures increase production. research can further enrich system which conducive efficient extraction, great promote realization carbon peak neutrality.