Forward Modeling of Azimuthal Anisotropy to the Reflected P Wave of Coal Seam
Forward Modeling of Azimuthal Anisotropy to the Reflected P Wave of Coal Seam作者机构：School of Mechanical and Civil Engineering China University of Mining ＆ Technology Beifing 100083 China School of Resource and Earth Sciences China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China
出 版 物：《Journal of China University of Mining and Technology》 (中国矿业大学学报（英文版）)
年 卷 期：2006年第16卷第3期
页 面：321-324页
核心收录：
学科分类：081801[工学-矿产普查与勘探] 081802[工学-地球探测与信息技术] 08[工学] 0818[工学-地质资源与地质工程]
主 题：coal seam composite wave anisotropy P wave
摘 要：Under the condition of weak anisotropy, the relation of P-wave anisotropy in direction to fractures of coal seams was researched in order to forecast the density and the direction of the fractures. Although the approximate solution by Rtiger is suitable for thick reservoirs, it has some limitations for the composite reflected wave from both roofs and floors of coal seams, as well as multiple reflections. So first, the phase velocity and group velocity as well as their travel time were calculated about the reflected P-wave of the coal seam. Then, the anisotropic coefficients of both roofs and floors were calculated by Rueger formulae and last, the section versus azimuth in fixed offset can be gotten by convolution. In addition, the relation of amplitude of the composite reflected wave to azimuth angle was discussed. The forward modelling results of the coal azimuth anisotropy show these： 1） the coal seam is the strong reflecting layer, but the change of the reflectivity caused by the azimuth anisotropy is smaller; 2） if the azimuth angle is parallel to the crack strike, the reflectivity reaches up to the maximum absolute value, however, if the azimuth angle is perpendicular to the crack strike, the absolute value of the reflection coefficient is minimum; and 3）the reflection coefficient is the cosine function of the azimuth angle and the period is π.
维普期刊数据库
同方期刊数据库