Abstract
In the process of multiseam combined drainage, the critical desorption pressure (Pcd) is the basic measurement index for determining whether a multigas-bearing system can be combined with drainage, and it is the basic index for identifying effectively the contributions of productive strata. In actual exploration and development processes, the Pcd is constrained by geological factors, engineering factors and economic factors, and the Pcd of some key coal seams cannot be determined effectively, which restricts the efficient development and utilization of coalbed methane. Accurate prediction of the Pcd of multiple coal seams under formation conditions has become a key requirement. In this study, medium-rank and high-rank coal samples were collected from the main synclines in Eastern Yunnan and Western Guizhou. By introducing the fractal dimension using nuclear magnetic resonance and the Pearson–Spearman correlation coefficient, the influences of coal metamorphism, pore structure, coal quality, temperature (T), and others on coal adsorption capacity were revealed. The results showed that, affected by the hydrocarbon generation and evolutionary processes of coal, fractal dimensions of adsorption pore (D3) and seepage pore (D4), the ratio of vitrinite to inertinite (V/I), the Langmuir volume (VL) and Langmuir pressure (PL) showed segmentation as the degree of metamorphism increased significantly. Bounded by random reflectance Rr = 1.30%, before Rr = 1.30%, with increase in metamorphic grade, VL and Rr showed “U” type change due to the change of molecular structure, maceral content, and structure of seepage pore, and then the evolution of hydrocarbon generation was weakened mainly by the influence of coal and rock components, showing linear change. The slopes of PL and Rr were larger before Rr = 1.30% than after Rr = 1.30%. The variation in PL with metamorphic degree was controlled mainly by the seepage capacity of coal rock, followed by the macerals of coal rock. Based on these results, the Levenberg–Marquardt algorithm was used with Rr and T as independent variables, VL and PL as dependent variables, and the R2 as the judgment value. A piecewise equation for calculating adsorption parameters with a high-fitting degree was obtained. Combined with the Langmuir equation, the prediction equation of Pcd can be calculated under the conditions of Rr and T and the measured gas content of known key coal seams. The correlation between the prediction equation and the measured parameters was high, and the identification template of Pcd of medium–high-rank coal in the study area was given. The new calculation method is more convenient for obtaining parameters and can be applied effectively to coal seams without the need to perform isothermal adsorption tests.
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References
Fu, Y., Liu, X., Ge, B., & Liu, Z. (2017). Role of chemical structures in coalbed methane adsorption for anthracites and bituminous coals. Adsorption, 23, 711–721.
Guo, D., & Guo, X. (2018). The influence factors for gas adsorption with different ranks of coals. Adsorption Science & Technology, 36, 904–918.
Hodot, B. B. (1966). Outburst of coal and coalbed gas (Chinese translation). China Industry Press.
Horio, M., Morimoto, J., & Tabuchi, T. (2008). A method for nonlinear least squares problem. Technical Bulletin of Tokushima Bunri University, 75, 81–95.
Jin, Y., Dong, J., Zhang, X., Li, X., & Wu, Y. (2017). Scale and size effects on fluid flow through self-affine rough fractures. International Journal of Heat and Mass Transfer, 105, 443–451.
Jin, Y., Li, X., Zhao, M., Liu, X., & Li, H. (2017). A mathematical model of fluid flow in tight porous media based on fractal assumptions. International Journal of Heat and Mass Transfer, 108, 1078–1088.
Kang, J. Q., Fu, X. H., Jian, K., & Li, X. (2019). Characteristics of the physical parameters and the evolution law of anthracite around the coalification jump: A case of the Jincheng and Guxu mining area, China. Energy Exploration & Exploitation, 37, 1205–1226.
Langmuir, I. (1917). The adsorption of gases on plane surfaces of glass, mica and platinum. Journal of the American Chemical Society, 40(9), 1361–1403.
Li, J., Qin, Y., Chen, Y., Luo, Q., Deng, J., Guo, S., Zhong, N., & Chen, Q. (2021). Differential graphitization of organic matter in coal: Some new understandings from reflectance evolution of meta-anthracite macerals. International Journal of Coal Geology, 240, 103747.
Li, Y., Zhang, C., Tang, D. Z., Gan, Q., Niu, X. L., Wang, K., & Shen, R. (2017). Coal pore size distributions controlled by the coalification process: An experimental study of coals from the Junggar, Ordos and Qinshui basins in China. Fuel, 206, 352–363.
Lin, Y., Qin, Y., Ma, D., & Duan, Z. (2021). Pore structure, adsorptivity and influencing factors of high-volatile bituminous coal rich in inertinite. Fuel, 293, 120418.
Liu, X., & He, X. (2017). Effect of pore characteristics on coalbed methane adsorption in middle-high rank coals. Adsorption, 23, 3–12.
Matin, S. S., Hower, J. C., Farahzadi, L., & Chelgani, S. C. (2016). Explaining relationships among various coal analyses with coal grindability index by Random Forest. International Journal of Mineral Processing, 155, 140–146.
More, J. J. (1978). The Levenberg-Marquardt algorithm: Implementation and theory. Numerical Analysis. https://doi.org/10.1007/BFb0067700
Mukherjee, I., & Routroy, S. (2012). Comparing the performance of neural networks developed by using Levenberg-Marquardt and Quasi-Newton with the gradient descent algorithm for modelling a multiple response grinding process. Expert Systems with Applications, 39, 2397–2407.
Perera, M. S. A., Ranjith, P. G., Choi, S. K., Airey, D., & Weniger, P. (2012). Estimation of gas adsorption capacity in coal: A review and an analytical study. International Journal of Coal Preparation and Utilization, 32, 25–55.
Qin, Y., Moore, T. A., Shen, J., Yang, Z., Shen, Y., & Wang, G. (2018). Resources and geology of coalbed methane in China: A review. International Geology Review, 60, 777–812.
Qin, Y., Shen, J., & Shen, Y. (2016). Joint mining compatibility of superposed gas-bearing systems: A general geological problem for extraction of three natural gases and deep CBM in coal series. Journal of China Coal Society, 41(01), 14–23.
Rubio, J. D. (2021). Stability analysis of the modified Levenberg-Marquardt algorithm for the artificial neural network training. IEEE Transactions on Neural Networks and Learning Systems, 32, 3510–3524.
Setzmann, U., & Wagner, W. (1991). A new equation of state and tables of thermodynamic properties for methane covering the range from the melting line to 625 K at pressures up to 100 MPa. Journal of Physical and Chemical Reference Data, 20(6), 1061–1155.
Sheikh, H. R., Sabir, M. F., & Bovik, A. C. (2006). A statistical evaluation of recent full reference image quality assessment algorithms. IEEE Transactions on Image Processing, 15(11), 3440–3451. https://doi.org/10.1109/TIP.2006.881959
Singh, P. K. (2011). Geological and petrological considerations for coal bed methane exploration: A review. Energy Source Part A, 33, 1211–1220.
Strategy Research Center of Oil and Gas Resources Department. (2006). The Ministry of land and resources. Assessment of coalbed (pp. 1–300). China Land Press.
Su, Y. J., Liu, X., Teng, Y., & Zhang, K. (2021). A preliminary study on dependence of mercury distribution on the degree of coalification in Ningwu Coalfield, Shanxi, China. Energies, 14(11), 3119.
Sun, W., Lin, H., Li, S., Kong, X., Long, H., Yan, M., Bai, Y., & Tian, J. (2021). Experimental research on adsorption kinetic characteristics of CH4, CO2, and n2 in coal from Junggar Basin, china, at different temperatures. Natural Resources Research, 30(3), 2255–2271.
Sun, Z., Shi, J., Wu, K., Zhang, T., Feng, D., & Li, X. (2019). Effect of pressure-propagation behavior on production performance: Implication for advancing low-permeability coalbed-methane recovery. SPE Journal, 24(02), 681–697.
Tao, S., Chen, S. D., Tang, D. Z., Zhao, X., Xu, H., & Li, S. (2018). Material composition, pore structure and adsorption capacity of low-rank coals around the first coalification jump: A case of eastern Junggar Basin, China. Fuel, 211, 804–815.
Yan, J. W., Meng, Z. P., & Li, G. Q. (2021). Diffusion characteristics of methane in various rank coals and the control mechanism. Fuel, 283, 118959.
Yang, Y., Liu, S., Zhao, W., & Wang, L. (2019). Intrinsic relationship between Langmuir sorption volume and pressure for coal: Experimental and thermodynamic modeling study. Fuel, 241, 105–117.
Yang, Z., Li, Y., Qin, Y., Sun, H., Zhang, P., Zhang, Z., Wu, C., Li, C., & Chen, C. (2019). Development unit division and favorable area evaluation for joint mining coalbed methane. Petroleum Exploration and Development, 46, 583–593.
Yang, Z., Peng, H., Zhang, Z., Ju, W., Li, G., & Li, C. (2019). Atmospheric-variational pressure-saturated water characteristics of medium-high rank coal reservoir based on NMR technology. Fuel, 256, 115976.
Yang, Z., Zhang, Z., Qin, Y., Wu, C., Yi, T., Li, Y., Tang, J., & Chen, J. (2018). Optimization methods of production layer combination for coalbed methane development in multi-coal seams. Petroleum Exploration and Development, 45, 312–320.
Yao, Y., Liu, D., Che, Y., Tang, D., Tang, S., & Huang, W. (2010). Petrophysical characterization of coals by low-field nuclear magnetic resonance (NMR). Fuel, 89, 1371–1380.
Zhang, R., & Liu, S. M. (2017). Experimental and theoretical characterization of methane and CO2 sorption hysteresis in coals based on Langmuir desorption. International Journal of Coal Geology, 171, 49–60.
Zhang, J. J., Wei, C. T., Ju, W., Yan, G. Y., Lu, G. W., Hou, X. W., & Kai, Z. (2019). Stress sensitivity characterization and heterogeneous variation of the pore-fracture system in middle-high rank coals reservoir based on NMR experiments. Fuel, 238, 331–344.
Zhang, M., Fu, X., & Wang, H. (2018). Analysis of physical properties and influencing factors of middle-rank coal reservoirs in China. Journal of Natural Gas Science Engineering, 50, 351–363.
Zhang, S., Liu, H., Jin, Z., & Wu, C. (2021). Multifractal analysis of pore structure in middle- and high-rank coal by mercury intrusion porosimetry and low-pressure n2 adsorption. Natural Resources Research. https://doi.org/10.1007/s11053-021-09952-z
Zhang, Z., Qin, Y., & Fu, X. (2014). The favorable developing geological conditions for CBM multi-layer drainage in southern Qinshui basin. Journal of China University of Mining & Technology, 43(06), 1019–1024.
Zhao, J., Qin, Y., Shen, J., Zhou, B., Li, C., & Li, G. (2019). Effects of pore structures of different maceral compositions on methane adsorption and diffusion in anthracite. Applied Sciences, 9(23), 5130.
Zhu, C. G., & Wang, R. H. (2007). Least squares fitting of piecewise algebraic curves. Mathematical Problems in Engineering. https://doi.org/10.1155/2007/78702
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Financial support for this work was provided by the National Natural Science Foundation of China (No. 41772155), the National Major Research Program for Science and Technology of China (No. 2016ZX05044002), and Major Science and Technology Special Funding Projects of Shanxi (20201102001).
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Li, C., Yang, Z., Chen, J. et al. Prediction of Critical Desorption Pressure of Coalbed Methane in Multi-coal Seams Reservoir of Medium and High Coal Rank: A Case Study of Eastern Yunnan and Western Guizhou, China. Nat Resour Res 31, 1443–1461 (2022). https://doi.org/10.1007/s11053-022-10034-x
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DOI: https://doi.org/10.1007/s11053-022-10034-x