地震测井联合反演技术在南黄海盆地北部坳陷中生代储层预测中的应用

APPLICATION OF SEISMIC-LOG JOINT INVERSION TO PREDICTION OF MESOZOIC SANDSTONE RESERVOIR IN NORTH DEPRESSION OF SOUTH YELLOW SEA BASIN

在构造复杂和测井资料少的海域,有效地进行地震反演和储层预测是油气前景评价的关键。针对南黄海盆地白垩系砂岩储层中岩性复杂和物性高度非均质的问题,采用了测井、地震资料联合的稀疏脉冲约束反演方法和构造形态约束下的低频模型构建技术,对二维多道地震数据进行了目标层波阻抗反演处理,并对白垩纪砂岩储层的横向分布进行了追踪预测。结果表明:地震波阻抗剖面能够刻画储层的空间展布特征,表征储层内部物性变化,预测有利储层分布范围;储层预测认为白垩系泰州组发育多层低波阻抗的泥岩生烃层,中间夹两层波阻抗较高的砂层,与钻井资料对比为物性较好的油气储集层。

In the exploration areas with complicated tectonic background and few drilling wells, effective seismic wave impedance inversion processing and reservoir prediction are the keys to offshore oil and gas resource assessment. For the seriously heterogeneous and complex lithologic association of the Cretaceous sandstone reservoirs in the South Yellow Sea Basin, wave impedance inversion processing is performed for 2D multi-trace seismic data, using the methods of seismic-log sparse impulse joint constrained inversion and low-frequency model building technique under the constraints of structural framework. The wave impedance inversion section may depict spatial distribution pattern of the reservoir, show physical changes inside the reservoir and predict the distribution pattern of the prospective reservoir. The reservoir prediction suggests that the Cretaceous Taizhou Formation has a multi-layer mudstone as hydrocarbon source rocks with low wave impedance,and there are two layers of sandstone reservoirs with high wave impedance. Compared with drilling data, it is proved that the sandstone reservoir is valuable.