松辽盆地英台断陷营二段火山碎屑岩储层预测技术

Pyroclastic Rock Reservoir Prediction about Second Member of Yingcheng Formation in Yingtai Rift, Songliao Basin

松辽盆地南部英台断陷五棵树地区下白垩统营城组二段火山碎屑岩储层厚度薄,纵波阻抗值差异小,值域叠置严重,利用常规的波阻抗反演方法难以直接识别储层。在地震资料拓频处理的基础上,结合叠后地质统计学反演方法有效地解决了这一难题。利用地震资料深层拓频处理技术,目的层段优势频带得到明显展宽,能量明显增强,主频提高显著。叠后地质统计学反演方法兼顾了地震数据的横向分辨率与测井数据的纵向分辨率,通过叠后约束稀疏脉冲反演波阻抗体作为硬约束数据,建立阻抗值与储层参数的关系,反演得到的有效储层分布与钻井揭示的有效储层吻合程度高,能够反映储层物性的变化。地震资料处理与地震资料反演方法的联合攻关,对于解决薄储层的空间展布特征具有比较好的效果。

Pyroclastic rock reservoir is very thin in the second member of Yingcheng Formation in Lower Cretaceous of Wukeshu area in Yingtai Rift, Songliao Basin. Longitudinal wave impedance difference is small, serious and range overlay routine impedance inversion method is difficult to identify reservoir. Based on seismic data frequency broadening, stacked seismic statistical inversion method is used and solves this problem effectively. The dominant frequency band of the target layer is broadened, energy is increased, and the main frequency is increased significantly, by the use of deep frequency broadening technology. Poststack geostatistics takes into account the vertical resolution of seismic data and the lateral resolution of logging data. By taking the poststack constrained sparse spike inversion of the wave impedance of the body as hard constraints on data, the relationship between impedance and reservoir parameters is established. The effective reservoir distribution obtained from inversion and the effective reservoir displayed by drilling reveals high degree of agreement, which could reflect the change in reservoir properties. Joint research on seismic data processing and seismic data inversion method could reach better result for solving thin reservoir spatial distribution characteristics.