谱反演拓频处理技术在车排子地区白垩系储层描述中的应用

APPLICATION OF THE SPECTRAL-INVERSION EXTENDED FREQUENCY PROCESSING TECHNIQUE IN THE CHARACTERIZATION OF CRETACEOUS RESERVOIRS IN CHEPAIZI AREA

由于受分辨率的影响,基于原始地震资料对薄储层的描述难度较大,故需对叠后资料进行拓频处理。常规反褶积难以对反射系数和子波两个主要因素进行质量控制,而谱反演得到的反射系数数据体可通过井上精细标定的声波曲线进行精确质量控制,并与构建的零相位宽频子波褶积获得拓频数据体,具有更好的保幅性。该方法在准噶尔盆地西缘车排子地区白垩系薄储层描述中应用取得了预期效果。预测结果显示:靶区白垩系砂体厚度为3 m左右,垂向上主要发育在呼图壁组底部,平面上近岸区域砂体规模较大,远岸区域单砂体面积为2 km2左右;通过精细刻画靶区砂体分布,揭示了以滨浅湖沉积为主局部扇三角洲的沉积特征,这些认识与现有地质认识一致。

Due to the influence of the resolution,it is difficult to characterize the thin reservoirs based on the original seismic data,so it is needed to extend the frequency bands of the post-stack seismic data. The conventional deconvolution is difficult to control the qualities of the two main influencing factors：reflection coefficient and wavelet,while the reflection coefficient data body obtained from the spectral inversion can precisely control the quality of the acoustic curves accurately calibrated by the wells,and moreover can get the extended-frequency data body with the help of the established zero-phase wide-frequency wavelet convolution,so the much better property of the amplitude protection can be achieved. The predicted effects of the method were obtained in the characterization of Cretaceous thin reservoirs in Chepaizi area of the western margin of Junggar Basin. The results show that the average thickness of the Cretaceous sandbodies in the target area is about 3 meters,the sandbodies are vertically and generally devel-oped in the bottom of Hutubi Formation,while on the horizon,the sandbody size is pretty vast in the nearshore area,the far-shore individual sandbody area is around 2km2; by means of the fine description of the sandbody distribution in the target area,the sedimentary characteristics of the partial fan-delta principally deposited in the shore and shallow lake are revealed. These understandings are consistent with the existing geological knowledges.