关于“气煤弹性各向异性系数实验测试”一文的讨论

Discussion on the paper "Test on elastic anisotropy coefficients of gas coal"

研究、确定气煤弹性各向异性的类型和大小,对煤田地震各向异性理论的研究具有重要意义."气煤弹性各向异性系数实验测试"一文通过对15块气煤岩样的超声测量,对气煤的弹性各向异性特征进行了分析,获得了对气煤地震勘探有指导意义的结论.但该文的一些理论概念和公式的使用及结论的获得有值得商榷的地方.本文针对此提出了一些修正意见,并利用该文的测试数据进行了补充分析,获得了气煤弹性各向异性相对完整的认识.

Studying and determining the type and magnitude of anisotropy of gas coal is of important significance for studying the seismic anisotropy theory of a coal field. In the paper, ＂Test on elastic anisotropy coefficients of gas coal＂, the fifteen gas coal samples were measured by ultrasonic wave. On the basis of this, they measured the P wave velocity and the horizontal and vertical components of S-wave velocity in three directions parallel to, perpendicular to, and an angle of 45° to the coal seam, and calculated the elastic constants. They analyzed the characteristic of the elastic anisotropy of gas coal and obtained instructive conclusions for seismic exploration on gas coal. However, it is worth discussing on some theoretical concepts and formulae used in the paper. The conclusions obtained in the paper also need to be discussed. In this paper, on account of this, we put forward some amendments. The results show that the anisotropy of gas coal is caused by fine layering of isotropic materials according to the view of Thomsen. Making a supplement analysis of the test datum in the paper, we obtain a relatively complete understanding of the elastic anisotropy of gas coal.