三角洲平原高弯曲分流河道内部结构单元三维建模

Three Dimensional Architectural Model of the High Sinuous Distributary Channels on Delta Plain

以大庆萨尔图油田北三区西部西块SⅡ12小层典型三角洲平原高弯曲分流河道为例,进行了三角洲平原高弯曲分流河道内部结构单元建模。首先根据高弯曲分流河道沉积层次性,以及河流弯曲机理,解剖了分流河道内部结构,识别出点坝以及侧积层单元,提取了侧积层形态参数和统计参数。其次采用椭球形方程建立了侧积层平面数学函数表达式,采用直线方程描述侧积层剖面形态,从而建立侧积层空间三维几何形态。最后,分两步建立了高弯度分流河道内部结构单元三维地质模型。首先采用序贯指示建模建立分流河道微相模型;随后根据侧积层数学模型描述侧积层空间分布。并在分流河道微相内部将侧积层模型嵌入,形成精细的高弯曲分流河道内部结构模型。以此思路为指导建立了SⅡ12小层结构模型,以此结构模型为基础的储层参数模型很好地再现了点坝内部侧积层对流体渗流的遮挡,为油藏数值模拟和剩余油挖潜奠定了基础。

The paper, taking the SⅡ12 layer of Saertu Oilfield as an example,provided a modeling method to construct the three dimensional architectural model of high sinuous distributary channels on delta plain.According to the sedimentary hierarchy and the migration mechanisms of meandering river, the architecture elements of the sinuous distributary channel such as point bar and inclined heterolithic stratification are recognized. The geometry and statistics parameters of inclined heterolithic stratification are extracted and the mathematical function are formed by elliptical function in horizon and line function in profile. Then, the three dimensional architectural model of the high sinuous distributary channels constructed by two steps： first, using the sequential indicator simulation to construct the model of the high sinuous distributary channels and associated microfacies; second, the inclined heterolithic stratification is modeled and embedded under the constrains of the distributary channels. The properties models are constructed by the final architectural model and show the barriers of inclined heterolithic stratification which affect the flow of the oil and water. So the models will contribute to the reservoir simulation and enhancement of remaining oil.