We present the longitudinal (V_P) and shear (V_S) wave velocities and their anisotropy of coal-samples under dry, water, and partially CO₂ saturated conditions. The elastic-constants have also been subsequently computed and presented. The results show that the V_S generally increases when the pores are filled with a less compressible fluid which effectively raises the bulk modulus. V_P depends on the combination of both bulk and shear modulus; it is highest for partially CO₂ saturated samples when the combined values of bulk and shear moduli are highest. Velocity anisotropy of V_S is of comparable order for dry and partially CO₂ saturated samples (13.42 % and 15.08 %, respectively), while wet samples show the lowest V_S anisotropy (5.44 %). For V_P, the wet samples exhibit 2.75 % lower anisotropy than dry samples; while partially CO₂ saturated samples have the highest V_P anisotropy (15.62%). The relationships between V_S and V_P, Young’s Modulus (E) and V_P under different fluid saturation in pores are quantified and presented using a linear regression method. Correlation between the ratio of the square of V_P and V_S and Poisson’s ratio was performed by polynomial fitting. Hypothesis testing (T-test) has been conducted on regression relationships using T statistics. We show that the regression relationships among all elastic parameters and ultrasonic wave velocities are not occurring by chance; rather true relationships prevail between the parameters under consideration. We finally conclude that under atmospheric or low confinements, the elastic properties of coal reservoirs are hardly affected by the type of pore fluids present in the reservoir.

我们介绍了煤样品在干燥，水和部分CO ₂饱和条件下的纵波（V _P）和横波波速（V _S）及其各向异性。弹性常数也随后进行了计算和表示。结果表明，当孔中填充压缩性较小的流体时，V _S通常会增加，从而有效地提高了体积模量。V _P取决于体积模量和剪切模量的组合。当体积模量和剪切模量的组合值最高时，对于部分CO ₂饱和样品，该值最高。V _S的速度各向异性是可比为了干燥和部分CO的₂饱和的样品（分别为13.42％和15.08％，），而湿样品显示最低V_小号各向异性（5.44％）。对于V _P，湿样品的各向异性比干样品低2.75％。而部分CO ₂饱和样品的V _P各向异性最高（15.62％）。利用线性回归方法对孔隙中不同流体饱和度下的V _S和V _P，杨氏模量（E）和V _P之间的关系进行了量化和表示。平方的比率之间的相关性V _P和V _S以及泊松比通过多项式拟合进行。已使用T统计量对回归关系进行了假设检验（T检验）。我们发现所有弹性参数和超声波速度之间的回归关系并不是偶然发生的；所考虑的参数之间确实存在真正的关系。我们最终得出结论，在大气或低密闭条件下，煤储层的弹性几乎不受储层中孔隙流体类型的影响。