鄂尔多斯盆地长8段纵横波速度岩心测定与分析

The core measurement and analysis with s- and the p-wave velocity in the Chang8 Member of Ordos basin

岩石的波速与衰减是地球物理勘探中的两个重要参数，为了研究它与储层的物性和含气性之间的关系，在一定温压条件下．用超声波测试了鄂尔多斯盆地长8段的砂岩样品的纵波速度、横波速度及不同饱和度下的纵波速度、横波速度和衰减Q值，并给出纵波速度、横波速度之间的关系式，讨论了围压、孔隙度、含水饱和度对岩石纵波速度、横波速度的影响，实验结果表明：随着围压的增加、纵波速度、横波速度都以对数的形式增加；随着含水饱和度的减少，纵波速度减小，横波速度不变，纵波Q值越大；孔隙度越大，岩石物性越好，纵波速度、横波速度越低。根据实验结果和相应的影响机理，可以为储层预测提供有力依据。

The wave＇ s velocity and attenuation in rock are two important parameters in geophysical exploration. Under certain tempera- ture and pressure conditions, the shear- and eompressional-wave＇ s velocity in the sandstone core samples from the Chang8 Member of the north Ordos basin, and the shear- and compressional^wave＇ s velocity, the Q-value of the attenuation under the different satura- tions are measured with ultrasonic in order tO research the relationship between the wave ＇ s velocity ＆ its attenuation in rock and the reservoir＇s physieal properties ＆ the hydrocarbon,bearingness. And the relational expression between the shear-wave＇s velocity and compressional-wave＇ s velocity is given in the paper. Influence of the confining pressure, porosity, water saturation on shear- and com- pressional-wave＇s velocities in the rock was discussed. The experiment results show that： with increase of the confining pressure, shear- and compressional-wave＇ s velocities increase in a logarithmic form; with reduction of the water saturation, the compressional wave velocity decreases, but the shear wave velocity is invariant. The greater the Q value of longitudinal wave, the greater the porosity is; the better the physical properties of the rock, the lower the shear- and cnmpressional-wave＇ s velocities are.Aecording to the experimental results and the corresponding impact mechanism, it can provide a strong basis for the reservoir prediction.