Research on the gas migration trend and mechanism of the transition flow regime in coal based on MRT-LBM simulation
MetadataShow full item record
In order to reveal the process and mechanism of gas flow in a low-permeability coal seam, a new multiple-relaxation-time lattice Boltzmann method (MRT-LBM) model of gas migration in coal micro/nanopores based on Langmuir monolayer adsorption theory, the slip boundary scheme and Bosanquet effective viscosity was established. The software MATLAB was used to carry out the simulation study of uniform pore gas flow based on the MRT-LBM model, and the results were compared and verified with the porous anodic alumina membrane gas flow experimental results. On this basis, the gas flow in coal pores with different micro/nanopore sizes considering adsorption was simulated. The results show that the dimensionless permeability coefficient increases with decreasing pore size under the same pressure, which reflects the subsequent enhancement of the microboundary constraint effect and reveals that the pore system becomes the main controlling factor of coal seam permeability within the coal matrix in the middle and late stages of coal seam gas extraction, while the role of the microboundary constraint effect needs to be considered. The gas adsorption layer weakens the pore gas flow capacity, but for pores with a radius greater than 16 nm, the apparent change in permeability caused by the adsorption layer is less than 5%, and the adsorption effect can be ignored. N2, CH4, and CO2 enter the transition flow regime under different pressure conditions; with gas extraction, the gas pressure decreases, and the difference in the gas flow characteristics of the three gases increases.
Showing items related by title, author, creator and subject.
Al Hinai, Adnan Saif Hamed; Rezaee, M. Reza (2015)Assessing shale formations is a major challenge in the oil and gas industry. The complexities are mainly due to the ultra-low permeability, the presence of a high percentage of clay, and the heterogeneity of the formation. ...
Experimental investigation on variation of physical properties of coal particles subjected to microwave irradiationHu, G.; Yang, N.; Xu, Guang; Xu, J. (2017)The gas drainage rate of low-permeability coal seam is generally less than satisfactory. This leads to the gas disaster of coal mine, and largely restricts the extraction of coalbed methane (CBM), and increases the emission ...
Experimental study on physical structure properties and anisotropic cleat permeability estimation on coal cores from ChinaXu, X.; Sarmadivaleh, Mohammad; Li, C.; Xie, B.; Iglauer, Stefan (2016)Knowledge of the natural structure properties of coal seams is essential for the coal bed methane (CBM) production because of their great influence on the inner flow characteristics and permeability features of hydrocarbons ...