Hou Haihai, Huang Xiangqin, Shao Longyi, Liang Guodong
College of Mining, Liaoning Technical University, Fuxin 123000, China.
College of Geoscience and Surveying Engineering, China University of Mining and Technology, Beijing 100083, China.
ACS Omega. 2022 Dec 7;7(50):46972-46982. doi: 10.1021/acsomega.2c06007. eCollection 2022 Dec 20.
The parameters of coal petrology and methane adsorption are significant to exploit coal and coalbed methane (CBM). Based on borehole core sampling, a new method using the P-wave velocity to predict coal maceral, coal face index, and Langmuir parameter of high-volatile bituminous coals was proposed. The results showed that the P-wave velocity correlated positively with coal skeletal density, apparent density, and ash yield with fitting coefficients ( ) of 0.55, 0.57, and 0.57, respectively, but it negatively correlated with coal porosity and moisture content with of 0.56 and 0.60, respectively. Vitrinite, ranging from 14.8 to 82.7% with an average of 53.8%, positively correlated with coal porosity due to more micropores in vitrinite and thus negatively correlated with the density and P-wave velocity. Inertinite content was in the range of 5.4 to 27.4% with an average of 11.0%, which correlated negatively with the coal porosity and thus positively with the density and P-wave velocity for most of the samples. Furthermore, the P-wave velocity was weakly positively correlated with mineral content, and a negative correlation was found between the P-wave velocity and vitrinite/inertinite ratio (V/I), gelification index (GI), and Langmuir volume ( ). The porosity ( ), vitrinite content ( ), inertinite content ( ), and ( ) of coals could be predicted based on the equations as follows: = 7842.4 e , = -0.0003 + 1.0731 - 924.09, = 0.0003 - 1.2797 + 1405, and = -0.04 + 101.24, where is the P-wave velocity. Generally, P-wave velocity could be largely used to predict the variations of the coal maceral and methane adsorption capacity of high-volatile bituminous coals, providing a new and valuable approach for CBM exploration and gas prevention in coal mines.
煤岩学参数和甲烷吸附参数对于煤炭及煤层气（CBM）的开采具有重要意义。基于钻孔岩芯采样，提出了一种利用纵波速度预测高挥发分烟煤的煤岩组分、煤面指数和朗缪尔参数的新方法。结果表明，纵波速度与煤的骨架密度、视密度和灰分产率呈正相关，拟合系数（ ）分别为0.55、0.57和0.57，但与煤的孔隙率和水分含量呈负相关， 分别为0.56和0.60。镜质组含量在14.8%至82.7%之间，平均为53.8%，由于镜质组中微孔较多，与煤的孔隙率呈正相关，因此与密度和纵波速度呈负相关。惰质组含量在5.4%至27.4%之间，平均为11.0%，对于大多数样品，其与煤的孔隙率呈负相关，因此与密度和纵波速度呈正相关。此外，纵波速度与矿物含量呈弱正相关，且纵波速度与镜质组/惰质组比（V/I）、凝胶化指数（GI）和朗缪尔体积（ ）呈负相关。煤的孔隙率（ ）、镜质组含量（ ）、惰质组含量（ ）和 （ ）可根据以下方程预测： = 7842.4 e ， = -0.0003 + 1.0731 - 924.09， = 0.0003 - 1.2797 + 1405， = -0.04 + 101.24，其中 为纵波速度。总体而言，纵波速度可在很大程度上用于预测高挥发分烟煤的煤岩组分和甲烷吸附能力的变化，为煤层气勘探和煤矿瓦斯防治提供了一种新的有价值的方法。
