基于改进的Kolsky模型波场延拓公式的纵波Q值、横波Q值估计

Estimation of P-and S-Waves Quality Factors Based on the Formula of the Wave-Field Continuation in Modified Kolsky Model

描述地层吸收作用的品质因子Q作为PP波和PS波联合反演中的一个重要物理参数,对地下岩石物性参数及油气预测起着重要的作用。以改进的Kolsky模型波场延拓物理机制为理论基础,结合Zhang和Ulrych提出的计算层旅行时方法,提出了基于改进的Kolsky模型波场延拓公式的纵波Q值、横波Q值估计方法。该方法是通过不同记录道间振幅谱比对数与频率的线性回归估计出一系列的Q值,然后通过筛选、平均处理得到各层位的Q值。模型试验中,估计出的P波、PS波Q值与理论Q值误差均小于2%,这表明了该方法估计Q值的正确性和估计结果的准确性。将本文方法应用于实际地震资料中,获得了合理的P波Q值估计结果。

The quality factor describing stratigraphic absorption ,which is an important physical parameter in joint inversion of PP-and PS-waves ,plays an important role in the prediction of subsurface petrophysical parameters and oil and gas .On account of the physical mechanism of wave-field continuation in modified Kolsky model ,and the method of calculating travel time in each layer proposed＆amp;nbsp;by Zhang and Ulrych ,We present a method for estimating P-and S-waves quality factors based on the formula of the wave-field continuation in modified Kolsky model .We estimate a series of Q values by linear-fitting between the frequency and the logarithm of the amplitude spectrum ratio between different seismic traces ,and then we obtain the Q value of each layer by selecting the better Q values and taking the average of them .In the model tests ,the errors between theoretical Q values of P-and S-waves and their estimated Q values using this method are less than 2% .It show s that the Q values estimated by this method are correct and the estimated results are accurate . We apply this method to real seismic data ,and get reasonable estimating results of P-waves Q value .