论文部分内容阅读
本文提出了转换波AVO极值属性,并在储层密度和纵波速度满足Gardner公式的基础上,推导了极值位置和极值振幅与界面两侧速度比平均值和横波反射系数的关系。极值点位置是速度比平均值的函数,且随速度比的增加而减小,转换波AVO曲线的极值是速度比平均值和横波反射系数的函数。针对理论模型,利用幂函数拟合得到较高精度的AVO曲线极值位置和极值振幅,反演得到比较准确的速度比和横波反射系数。得到的横波反射系数剖面比常规转换波叠加剖面更有明确的物理意义,为地质构造解释和转换波层位标定奠定了理论基础。最后把转换波AVO曲线幂函数拟合和极值属性反演纵横波速度比、横波反射系数的方法应用于某地区实际转换波共转换点道集,反演的速度比与纵横波测井计算的速度比较吻合。
In this paper, AVO extreme properties of converted wave are proposed. Based on the Gardner formula of reservoir density and longitudinal wave velocity, the relationship between the extreme position and extreme amplitude and the average velocity and the reflection coefficient of transverse waves on both sides of the interface are derived. The location of the extreme point is a function of speed over the average value and decreases as the speed ratio increases. The extreme value of the AVO curve of the converted wave is a function of the speed ratio average and the reflection coefficient of the transverse wave. Aiming at the theoretical model, the extremum amplitude and amplitude of the AVO curve with higher accuracy are fitted by the power function fitting, and the accurate velocity ratio and transverse reflection coefficient are obtained by inversion. The obtained shear wave reflection coefficient profile has more definite physical meaning than the conventional converted wave superimposed profile, which lays a theoretical foundation for the interpretation of geological structure and the calibration of converted-wave horizon. Finally, the power function fitting and extremum attribute inversion of AVO curve of converted wave are used to inversely reconstruct the S-wave velocity ratio and S-wave reflection coefficient. The method is applied to the actual conversion wave co-conversion point gathers in a certain area. The velocity ratio and P- The speed is more consistent.