岩石物理测试分析的Vp-Vs关系式的适用性分析

The rock physical analysis to test the applicability of the analysis of Vp-Vs relationship

选取渤海海域古近系19块岩石样品,采用MTS815超声波测试系统进行地层温压状态下的纵波速度与横波速度的测试,获得了上述岩样的纵、横波速度.然后,采用Castagna公式拟合得到了测试数据(纵、横波速度)的Vp-Vs关系式;再采用该关系式和研究区古近系地层的测井(7口取芯井)获得的纵波速度计算横波速度(预测的横波速度);发现预测的横波速度与测井获得的横波速度具有相同的宏观变化规律,但是存在一个常数差值.上述分析结论表明,岩石物理测试获得纵横波速度的关系式不能直接应用于测井的横波速度预测,需要进行常数校正.

We select 19 rock samples of Bohai Sea Area Eogene and use MTS815 ultrasonic wave velocity test system which tests wave velocity of the formation at the temperature and pressure state and obtains P-wave and S-wave velocity of these rock samples.Then,we use the Castagna formula to fit the relationship of Vp-Vs of the test data（P-wave and S-wave velocity）;using this relationship and the research area Eogene formation logging（9coring wells）obtained P-wave velocity to calculate the S-wave velocity（predicted S-wave velocity）;we find that the predicted and S-wave velocity obtained by well logging have the same variation,but it is a constant difference.The above analysis shows that the relationship of Vp-Vs obtained by rock physics test can not be directly applied to predict S-wave velocity of well logging,which requires constant correction.