论文部分内容阅读
调谐厚度范围内薄层厚度定量预测一直是地震勘探面临的挑战之一,目前多数讨论仅限于顶底反射系数等幅反极性的薄层,对于其他薄层类型尚无系统研究。本文将所有薄层划分为四类:等幅反极性薄层、不等幅反极性薄层、等幅同极性薄层、不等幅同极性型薄层;通过理论推导得到薄层地震峰值频率与厚度关系的一般表达式,针对该式为一个复杂非线性隐式、难于直接应用求取薄层厚度的难题,采用三角函数的泰勒展开式进行简化,给出每类薄层厚度定量估算的近似公式,并系统讨论了各阶近似公式的精度。与传统的利用振幅信息求取薄层厚度的方法相比,本文方法的精度更高,且不受顶底反射系数绝对大小的影响,便于实际应用。
Quantitative prediction of sheet thickness within tuning thickness has always been one of the challenges in seismic exploration. At present, most discussions are limited to sheet with opposite polarity with top and bottom reflection coefficients, and there is no systematic study on other sheet types. In this paper, all the thin layers are divided into four categories: the amplitude of the opposite polarity of the thin layer, non-equal amplitude of the opposite polarity thin layer, the same amplitude of the same polarity thin layer, the same width of the same polarity type thin layer; The general expression of the relationship between the peak seismic frequency and the thickness of seismic wave is a complex non-linear implicit method. It is difficult to directly apply the method to obtain the thickness of the thin layer. The Taylor’s expansion of trigonometric function is simplified. The approximate formula of the quantitative estimation of thickness is discussed systematically and the accuracy of the approximation formula of every order is discussed systematically. Compared with the traditional method which uses the amplitude information to obtain the thickness of the thin layer, the proposed method has higher accuracy and is not affected by the absolute size of the top and bottom reflectance, which is convenient for practical application.