深度域合成地震记录制作方法的研究与应用

Research and Application of Synthetic Seismic Record Making Method in Depth Domain

随着深度域地震资料的应用越来越广泛,在深度域直接提取地震子波制作合成地震记录变得越来越重要,但是在以往的生产项目中,人们大多将深度域地震数据通过时深转换,转换到时间域,制作完合成地震记录后再转换到深度域,导致误差增大和生产效率降低,所以,找到一种实用的直接在深度域制作合成地震记录的方法非常必要。本文利用常速度进行数学变换,将多层层状介质转换为具有常速度的均匀介质,这样就满足了线性条件的假设,然后深度域合成地震记录利用反射系数与深度域子波的褶积计算。其中,反射系数根据测井曲线计算获得,深度域子波是利用统计方法在原始地震数据上提取获得。本文利用该方法对淮南某矿区进行了深度域合成地震记录的制作,制作的合成地震记录和原始地震数据吻合度高,目的层深度误差几乎为零。研究结果表明,本文介绍的深度域合成地震记录制作方法可直接在深度域提取子波,不仅使合成地震记录更加精确,还提高了生产效率,该方法在实际生产中可推广运用。

With the widespread application of depth domain seismic data,it becomes increasingly important to directly extract seismic wavelet and produce synthetic seismic records in the depth domain.However,previous production researches tend to convert depth domain seismic data into time domain through time depth conversion,and then convert to depth domain after producing synthetic seismic records,which has led to increased errors and reduced production efficiency.So,it is necessary to find a practical method for directly producing synthetic seismic records in the depth domain.This article uses constant velocity for mathematical transformation to transform a multi-layer layered medium into a uniform medium with constant velocity,which satisfies the assumption of linear conditions,and enables the convolution of reflection coefficients and depth domain wavelets for calculation of deep domain synthetic seismic records.The reflection coefficient is calculated based on the logging curve,and the depth domain wavelet is extracted from the original seismic data using statistical methods.Using this method to produce deep domain synthetic seismic records for a certain mining area in Huainan,the synthesized seismic records produced have high consistency with the original seismic data,and the depth error of the target layer is almost zero.The production method of deep domain synthetic seismic records introduced in this article can directly extract wavelet in the deep domain,which not only makes synthetic seismic records more accurate,but also improves production efficiency,thus can be promoted and applied in practical production.