90°相位转换技术在预测砂体展布中的应用

以黄河口凹陷西洼沙河街二段为例,对研究区地震剖面进行90°相位转换,根据转换后的剖面岩性特征及地质背景概况建立地质模型,进行正演模拟分析;然后对比零相位与90°相位的正演合成记录,校准地质模型,并依据地震剖面振幅属性特征,对相位转换后的地震剖面进行属性提取,预测砂体的展布.研究发现,基于90°相位转换地震剖面建立的地质模型更具直观性,正演合成记录验证砂岩恰好对应于波谷,波形能清晰地展示出砂岩层的纵向轮廓,并且90°相位转换的地震波谷振幅值属性平面图能清晰显示出砂体的平面展布及分布范围.

APPLICATION OF 90°-PHASE SEISMIC DATA IN PREDICTION OF SANDSTONE

Abstract： Taking the 2na Member of Shahejie Formation in the Yellow River Mouth sag as an example, geological models were built depending on the 90° phasing of seismic data and the geologic setting. The modeling synthesis records from 0~-phase to 90°-phase were used to make the geological models more precise. Then according to the attributive character obtained from the 90°-phase of seismic data, seismic attributions extraction and formation slices could be used to predict the distribution of the sandstone. The results indicate that the geological models can be directly perceived through the 90°-phase seismic data, and at the same time the trough of waves can not only correspond to the sand body but also show the outline of the sand belt which is spreading in the seismic modeling synthesis of 90° phasing. What＇ s more, the ichnography from the seismic attribution extraction about the character of trough amplitude can clearly show the contour profiles and boundaries of the sandstone.