Zou Mingjun, Liu Yuanzheng, Huang Zhiquan, Zhang Miao, Zhang Peilun
College of Geosciences and Engineering, North China University of Water Resources and Electric Power, Jinshui East Road No. 136, 450045 Zhengzhou, China.
He'nan Province Research Institute of Coal Geological Prospecting, He'nan Coalfield Geological Bureau, Shangding Road No. 70, 450052 Zhengzhou, China.
ACS Omega. 2020 Apr 13;5(16):9540-9549. doi: 10.1021/acsomega.0c00782. eCollection 2020 Apr 28.
This paper adopts the measurement of mercury intrusion porosimetry and nuclear magnetic resonance (NMR) to analyze the pore system and the pore structure of coal samples, and the measurement of maceral group composition, scanning electron microscopy, and energy dispersive X-ray spectroscopy to obtain the organic/inorganic composition of coal samples. Gravimetric and NMR methods are both used to calculate irreducible water saturation of the samples, and qualitative and quantitative research studies are therefore conducted. The following knowledge is obtained. Coal samples can be classified as micro-trans-pore-dominated samples, meso-macro-pore-dominated samples, cleat-dominated samples, and even development samples. The main composition of the samples is organic, and a little kaolinite and pyrite can be observed. Irreducible water saturation obtained by the gravimetric method is almost close to that gained by the NMR method. The influencing parameters can be divided into two categories. The first category contains the maximum vitrinite reflectance, volumetric factor, fixed carbon yield, volatile yield, vitrinite percentage, and inertinite percentage, which have a strong correlation with irreducible water saturation. The second category includes the buried depth and median radius, and they have a weak correlation with irreducible water saturation. Multivariate regression shows that there is a linear quaternion equation between irreducible water saturation and independent variables such as maximum vitrinite reflectance, volumetric factor, volatile yield, and vitrinite percentage.
本文采用压汞法和核磁共振（NMR）测量来分析煤样的孔隙系统和孔隙结构，并采用煤岩组分测定、扫描电子显微镜和能量色散X射线光谱法来获取煤样的有机/无机组成。采用重量法和核磁共振方法计算样品的束缚水饱和度，进而开展定性和定量研究。得到以下认识。煤样可分为微孔主导型样品、中-大孔主导型样品、割理主导型样品和均匀发育型样品。样品的主要成分为有机质，可观察到少量高岭石和黄铁矿。重量法得到的束缚水饱和度与核磁共振法得到的结果相近。影响参数可分为两类。第一类包括最大镜质体反射率、体积因子、固定碳产率、挥发物产率、镜质体百分比和惰质体百分比，它们与束缚水饱和度有很强的相关性。第二类包括埋藏深度和中值半径，它们与束缚水饱和度的相关性较弱。多元回归表明，束缚水饱和度与最大镜质体反射率、体积因子、挥发物产率和镜质体百分比等自变量之间存在线性四元方程。
