牛庄凹陷砂岩体的地震解释新方法之探讨

DISCUSSION ON THE NEW APPROACH TO THE INTERPRETATION OF THE SEISMIC DATA OF THE SANDSTONES IN THE NIUZHUANG DEPRESSION

在牛庄凹陷下第三系生油岩地层中,由于三角洲沉积作用,形成了较多的砂岩透镜体油藏。这些砂体具有分布范围小、横向变化快、且互不连通的特点。勘探开发这类油藏的难度较大。本文从该地区的沉积特点出发,分析了砂岩体的地震反射特征,以王50砂体为例,系统地介绍了钻井资料,及综合利用合成记录、地震模型、波阻抗等各种信息,准确标定砂体反射波和定量解释的新方法;同时,对无井区砂体预测在方法上也进行了深入的研究,其成果经钻探验证,取得了很好的地质效果。

Many oil pools in the sandstone lenses are formed in the Eogene oil source beds in the Niuzhuang Depression as a result of deltaic deposition. These sandstone lenses are characterized by a small range of extention, a rapid horizontal variation and the isolation from one another. Oil pools of this kind are difficult to explore and tap.Considering the features of sedimentation in the area, the author studies the characteristics of the seismic reflections of the sandstone lenses. Taking the Wang 50 sandstone lens as an example, the author presents systematically the drilling well data and a new approach to determining accurately the reflection waves from the sandstone lenses on the seismic profiles and to interpreting the data quantitatively by analyzing and synthesizing various information from the known wells, including the synthetic seismograms,seismic modeland wave impedance Meanwhile, the author probes deeply into the methods for predicting the sandstone masses in undrilled areas, which are proved by drilling to have produced good results in the geological investigation.