随机优化地震反演在砂砾岩储层预测中的应用——以胜利油田盐22块油藏为例

Application of Stochastic Optimization of Seismic Inversion in Reservoir Prediction of Sandy Conglomerate Reservoirs——By Taking Reservoir in Block Yan 22 for Example

盐家油田盐22块砂砾岩体发育在东营凹陷陡坡带,为快速堆积、成层性差、横向变化快的近岸水下扇沉积。因其成因复杂,规律性差,常规波阻抗反演模型化严重,难以揭示储层内幕。而随机优化地震反演不需要繁杂的模型初始化,只需在对原始地震资料提频处理的基础上,在测井资料的声阻抗域进行求解。该方法在盐22块储层反演中成功应用,得到的反演结果更加符合砂砾岩沉积的特点,符合区域地质规律,相对常规反演具有较高的可信度,也为深层砂砾岩油藏的描述和开发积累了经验。

Block Yan 22 sandy conglomerate reservoir of Yanjia Oilfield was developed in the steep slope zone of Dongying Depression. The sediment was accumulated in a short time span and was poor in layering. It was a near-shore submerged fan sediment with fast change in the lateral direction. Because of its complex genesis,poor regularity,it was difficult to use conventional impedance inversion to reveal the internal structure of the reservoir. Complicated initial model was not needed by using stochastic optimization approach for seismic inversion. The problem was solved in the acoustic impedance domain of logging data by using the spectral enhanced seismic data. This method is successfully applied for reservoir inverting in Block Yan 22. The inversion results are consistent with the characteristics of sandy conglomerate sediments,and are more reliable than those from conventional inversion.