纹层方向对泥页岩纵、横波速度及弹性参数影响的试验研究

纵、横波速度是研究页岩各向异性的重要参数。为了研究纹层方向对纵、横波速度及动态弹性参数的影响,以我国东部中新生代的湖相泥页岩为研究对象,对不同纹层方向的取芯样品进行纵、横波速度实验。结果表明:纵横波波速比与纹层方向不具有相关性,与微裂缝的主要延伸方向有关;纵、横波传播方向与纹层的夹角越小,纵横波速度越大;不同纹层方向下的纵波速度和横波速度始终保持线性相关,其线性曲线的斜率、截距分别与纹层界面、微裂缝相关;动态弹性模量和纹层方向有良好的相关性,其主要受纹层界面影响,而动态泊松比与纹层方向无关,其主要受微裂缝影响。

Experimental study on influence of laminae direction on P-wave and S-wave velocities and elastic parameters of shale

P-wave and S-wave velocities are important parameters for studying shale anisotropy. In order to study the influence of the laminae direction on P-wave and S-wave velocities and dynamic elastic parameters,the Mesozoic and Cenozoic lacustrine shale in the eastern part of China was used as the research object,and P-wave and S-wave velocities experiments were carried out on the coring samples with different laminae directions. The results show that the ratio of P-wave and S-wave velocities has no correlation with the laminae direction,which is caused by the main extension direction of microcracks. The smaller the angle between the P-wave or S-wave propagation direction and the laminae direction,the greater the P-wave or S-wave velocity is. The P-wave and S-wave velocities in different laminae directions are always linearly correlated with each other. The slope and intercept of the linear curve are respectively related to the laminae interface and microcracks. The dynamic elastic modulus and the laminae direction have a good correlation,which is mainly affected by the laminae interface,while the dynamic Poisson?s ratio is independent of the laminae direction,which is mainly affected by microcracks.