90°相位旋转技术在储层预测中的应用——以鄂尔多斯盆地彬长区块长8-1油层组为例

Application of 90° phase rotation technique in reservoir prediction：A case study from the Chang8-1 reservoir in Binchang block,Ordos Basin

鄂尔多斯盆地彬长区块延长组长81是鄂尔多斯盆地南缘主要勘探开发层系之一,其上覆长73底部发育的张家滩页岩形成的地震强反射界面及长81储层较薄的地质沉积特征,造成常规地震数据体预测储层多解性较强。通过对张家滩页岩与长81储层速度、反射强度对比分析及组合模式的研究,提出了彬长区块长81油层组基于90°相位旋转技术的三维地震属性优选储层预测方法。运用90°相位旋转使地震反射的主要同相轴与地质上的储层有较好的对应,使地震相位具有岩性地层意义;运用正演模型分析、反射结构对比及多时窗属性优选等技术对目标储层进行预测,认为90°相位旋转下一定时窗内的反射强度及振幅属性能较好地对长81储层进行了预测。

Chang81reservoir in Binchang block is one of the main targets for petroleum exploration and development at the southern margin of the Ordos Basin. Because of the strong reflector resulted from the Zhangjiatan shale at the bottom of the overlying Chang 73 and the small thickness of the Chang81 reservoir,non-uniqueness exists when performing reservoir prediction by using conventional seismic data. On the basis of comparison and analysis of velocity and reflection intensity of the Zhangjiatan shale and the Chang81 reservoir and their combination patterns,reservoir prediction based on the 90 degree phase rotation technology of 3D seismic attribute is put forward for Chang81 reservoir in Binchang block.The main events of seismic reflection are well correlated with geological reservoirs by using the 90 degree phase rotation technology,so as to make the seismic phase having lithologic stratigraphic significance. Reservoir prediction was performed on the basis of the forward modeling,reflection structure comparison and multiple-window attribute optimization. It is believed that the reflection intensity and amplitude attribute within a certain time window under the 90 degree phase rotation can be used to more effectively predict Chang81 reservoir.