辽河油田古近系沙河街组三段储层宏观非均质性研究——以沈84-安12块储层为例

通过对本区辫状河三角洲沉积体系内各微相砂体的平面及空间展布、砂体的几何形态、孔渗特征等研究 ,揭示了辽河油田沈 84-安 1 2块古近系沙河街组三段储层的宏观非均质特征 .对沉积体系内河口坝及水下重力流砂体、水下分流河道砂体、辫状分流河道砂体、决口扇及决口河道砂体的几何形态特征及内部物性分布规律进行了重点分析 ,总结了本区储层特征 :单砂体多数呈正韵律 ,层内孔渗特征差异明显 ,单层层数多 ,砂体沉积微相变化快 ,储层在平面上及垂向上、层间及层内的非均质性较强 .并得出如下结论 :本区三角洲前缘的水下分流河道砂体和三角洲平原的辫状分流河道砂体均达到中孔、中高渗储层标准 ,是本区主要含油砂体 .

Study on the macroscopic heterogeneity of the reservoir in Shen-84-An-12 area of the third Member of Shahejie Formation of Peleogene,Liaohe Oilfield

The macroscopic heterogeneity of the reservoir is revealed through the analyses of the plane and spatial distributions, geometric form, porosity and permeability of the sandbodies of the different microfacies in the braided channel delta system in the area. The characteristics of geometric forms and the distribution features of physical properties of the river mouth bar and subqueous gravity flow sandbody, subqueous distributary channel sandbody, braided distributary channel sandbody, crevasse splay and crevasse channel sandbody in the braided channel delta system are emphatically studied. It is held that the reservoir characteristics of this area are that the most sandbodies show positive rhythm, the sedimentary microfacies of the sandbodies vary frequently, there is clear difference in porosity and permeability in single layer; the number of single layer is much, the lateral, vertical, inter-layer and in-layer heterogeneities are all serious. And a conclusion is drawn that the delta front subqueous distributary channel sandbody and delta plain braided distributary channel sandbody in this area reach to the standards of middle-permeability and middle-porosity reservoir, and they are main oil-bearing sandbodies in this area.