流体替代技术在北黄海盆地中生界含烃储层识别中的应用

Application of fluid substitution technique on the identification of Mesozoic hydrocarbon reservoir in the North Yellow Sea Basin

北黄海盆地中生界勘探目的层以陆相碎屑岩储层为主,埋藏较深,受沉积压实和胶结成岩作用的影响,储层物性较差,含油气有利储层识别难度较大。利用流体替代技术,依据已建立的岩石物理模型,结合实际流体温度、压力等参数,对特定泥质含量、孔隙度条件下储层弹性响应特征随不同流体饱和度的变化规律进行正演计算,从而建立了含油气有利储层的弹性参数刻画范围。研究结果表明,对于孔隙度>8%的物性相对较好的砂岩储层,其中含水的弹性属性与含油的弹性属性有一定的差别,而储层中含气的弹性属性与含油的弹性属性差别较为明显。因此,在研究区可以应用测量的纵波阻抗和模拟的纵横波速比建立含烃储层的解释框架,并利用叠前反演技术对研究区内物性较好有利储层作出预测。

In the North Yellow Sea Basin, the targeted Mesozoic reservoirs mainly consisted of deep buried continental clastic rocks. Due to compaction and cementation, the Mesozoic reservoirs have lower porosity and permeability, which makes it more difficult to identify the favourable hydrocarbon reservoirs. This paper used the forward modeling to calculate the variation of elastic character with different fluid saturation under specific condition of shale content and porosity based on the petro-physical model and the measured fluid temperature and pressure. Thus, the range of elastic parameters of favorable reservoir is established. The results show that in the reservoirs with sandstone of better porosity （greater than 8%）, the elastic attribute of reservoirs with water is different from that of reservoirs with oil, while the elastic attribute of reservoirs with gas is rather different from that of reservoirs with oil. So we can build the interpretation framework of hydrocarbon reservoirs using the measured primary wave impedance and simulated vp/vsratio. The favorable hydrocarbon reservoirs with better properties can be predicted using the pre stack inversion technique.