码头庄油田储层非均质性及其与剩余油分布的关系

Reservoir heterogeneity and its relation with remaining oil distribution in the Matouzhuang Oilfield

以码头庄油田庄2断块为研究对象,利用熵权算法求取非均质综合指数,以表征储层非均质特征;运用非均质综合指数建立储层非均质模型,分析储层层内、层间、平面和空间非均质性,探讨其与剩余油分布的关系。结果表明,各小层内非均质程度有较大差异。在各沉积微相中,滨浅湖砂坝呈较弱非均质性;水下分流间湾呈强非均质性;水下分流河道、河口坝呈中等偏较弱非均质性;前缘席状砂呈强非均质性。各小层层间非均质性呈中等—较强程度。平面上,非均质综合指数等值线主要呈北东、北西向展布,总体呈中等平面非均质性。沉积微相、成岩作用和长期注水开发等因素影响了储层非均质性。剩余油主要分布于呈弱非均质性的区域。

Taking Zhuang-2 fault block of the Matouzhuang Oilfield as an example,this paper computed heterogeneous synthetic index by means of entropy weight algorithm to characterize the reservoir heterogeneity,applied the synthetic index to establish heterogeneous model,analyzed the internal,interlayer,plane and space heterogeneity,and discussed the relationship between the heterogeneity and remaining oil.The result shows that there are great differences of heterogeneity among the sublayers.The heterogeneity is weak in shore-shallow lacustrine mixing beach,strong in subaqueous interdistributary bay,middle to weak in subaqueous distributary channel and mouth bar,and strong in front sand sheet.The interlayer heterogeneity is middle to strong.The heterogeneity in plane presents middle degree.Reservoir heterogeneity is affected by sedimentary microfacies,diagenesis and long-term waterflood.Remaining oil mainly distributed in the area where herterogeneity is weak.