地震分频技术在扇三角洲前缘砂体预测中的应用 ——以海拉尔盆地乌尔逊断陷铜钵庙断裂带南屯组为例

海拉尔盆地乌尔逊断陷构造复杂、断裂发育,发育扇三角洲前缘含油砂体。针对含油砂体分布范围小、厚度薄、预测难的问题,通过地震匹配追踪分频处理,得到频率域的离散调谐地震数据体,其地震剖面波形特征清晰、能量增强、分辨率提高。应用优势频率分频三维地震资料,精细刻画了铜钵庙断裂带南屯组扇三角洲前缘砂体的三维轮廓和有利储层分布,并通过综合分析认为铜钵庙断裂带受东部物源控制,发育扇三角洲—湖底扇—半深湖(深湖)沉积体系。该技术的预测结果符合地质规律,与钻井结果的吻合度较高。

Application of seismic frequency division technique in sand body prediction of fan delta front:taking Nantun Formation of Tongbomiao fault zone in Wuerxun fault depression of Hailaer Basin as an example

Wuerxun fault depression in Hailaer Basin is characterized by complex structure,developed faults and oilbearing sand bodies in fan delta front.In order to solve the problems of small distribution range,thin thickness and difficult prediction of oil-bearing sand body,the discrete tuned seismic data body in frequency domain is obtained by seismic matching and tracking frequency division processing.The waveform characteristics of single frequency seismic section are clear,the energy is enhanced and the resolution is improved.Based on 3D dominant frequency division seismic data,the 3D contour and favorable reservoir distribution of fan delta front sandbodies of Nantun Formation in Tongbomiao fault zone are finely depicted.Through comprehensive analysis,it is considered that Tongbomiao fault zone is controlled by eastern provenance and develops fan delta-sublacustrine fan-semi deep lake(deep lake)sedimentary system.The prediction results of this technology conform to the geological law and are in good agreement with the drilling results.