基于地震响应正演模型的薄砂层预测方法研究及应用——以塔河西部白垩系舒善河组为例

Research and Application of Thin Sand Layer Prediction Method Based on Seismic Response Forward Modeling--Taking the Cretaceous Shushanhe Formation in The West of Tahe Oilfield as an Example Tarim Basin

塔河油田西部白垩系舒善河组油气显示较活跃,具较大勘探潜力。由于储层变化快,单个砂体叠置关系复杂,具厚、薄储层共存,隔层薄特点。5 m以内薄层难以直接在地震反射剖面上成像,为薄砂层的精准预测带来一定难度。通过建立白垩系舒善河组储层不同断距、不同厚度、不同岩性组合含油气储层地震响应特征的正演模型,利用生物启发计算识别薄储层及边界、地震振幅属性,分析预测储层分布及横向变化规律,形成一套有效的超薄砂岩储层综合预测方法。结果表明,储层厚度2~5 m砂体预测准确率约70%,井吻合率达90%以上。

The Cretaceous Shushanhe Formation in the west of Tahe Oilfield shows relatively active oil and gas,and has great exploration potential.Due to rapid reservoir changes,the stacking relationship of individual sand bodies is complex,and thick and thin reservoirs coexist,with thin interlayer characteristics.Especially,thin layers within 5m are difficult to image directly on seismic reflection profiles,which poses certain difficulties for accurate prediction of thin sand layers.This study established a forward modeling of seismic response characteristics of Cretaceous Shushanhe Formation reservoirs with different fault pitches,thicknesses,and lithological combinations,using bio-inspired calculations to identify thin reservoirs and their boundaries,and analyzed and predicted reservoir distribution and lateral variation rules through seismic amplitude attribute analysis.Through the above research,an effective comprehensive prediction method for ultra-thin sandstone reservoirs have been formed.The results show that the prediction accuracy of sand bodies with a reservoir thickness of 2-5m is about 70%,and the well coincidence rate reaches over 90%.