论文部分内容阅读
本文提出一种衰减水层多次反射的方法。首先估计水底反射系数函数,再加上计算出的振幅函数,同时考虑振幅和波形来模拟所有阶的水底多次反射波。在频率-慢度域模拟水底的一次反射和多次反射。在数据模型中的振幅函数包括震源方向性函数、震源虚反射响应、检波器组方向性函数、接收点虚反射响应以及与炮检距有关的几何扩散项。在小炮检距范围内,我们可以假设海底反射系数仅与频率有关,可以用最小平方法估计。利用海底的一次反射波和一阶多次波估算数据中未知的比例常数。对每一个共中心点(CMP)位置,合成的水底反射系数是作为频率的函数来估算的。本文将此算法应用于北海的高分辨率数据。模型数据和记录的数据匹配很好,与叠加道相比,估算的一次波反射系数更具有地质意义。与应用同一数据的拉冬变换去多次波方法相比,基于模型的去多次波方法计算效率更高,多次波的剩余能量更少。
This paper presents a method of attenuating multiple reflections in aquifers. First estimate the bottom reflection coefficient function, plus the calculated amplitude function, and simulate all orders of the bottom multiple reflections with both amplitude and waveform. Simulate underwater and multiple reflections in the frequency-slowness domain. The amplitude function in the data model includes the source directivity function, the source ghost reflection response, the detector group directivity function, the receive-point ghost reflection response, and the geometric diffusion term related to the offset. Within a small offset, we can assume that the seafloor reflection coefficient is frequency-dependent and can be estimated by the least square method. Estimating the unknown proportionality constant in the data using the first and second order multiple waves of the seabed. For each co-centered (CMP) position, the composite bottom reflection coefficient is estimated as a function of frequency. This paper applies this algorithm to high-resolution data in the North Sea. The model data matches well with the recorded data, and the estimated primary reflection coefficient is more geologically significant than the overlay. The model-based de-multiplexing method is more efficient than the Laplace transform-multiple-wave method which applies the same data, and the residual energy of multiple waves is less.