利用数值模拟方法预测辫状河砂体几何形态

辫状河是自然界重要的河流类型之一。利用砂体沉积过程数值模拟方法可以预测辫状河砂体的几何形态。在建立了辫状河砂体沉积过程的数学方程后,根据现代辫状河沉积特征,设计了辫状河沉积过程的模拟条件,计算域长15km、宽10km,流量按50a一遇大洪水设计,模拟过程到1970a时,辫状河沉积过程基本达到平衡状态,此时砂体最大厚度约14m,出现在计算域2.5~3.5km处,以中砂沉积为主。计算过程中可识别6种沉积单元,包括辫状水道(砂体的平均长宽比2.45,平均宽厚比72.6)、纵向砂坝(平均长宽比2.02,平均宽厚比86.7)、斜列砂坝(平均长宽比2.27,平均宽厚比74.9)、废弃河道、堤岸、越岸沉积。主要沉积单元砂体几何参数之间的相关关系较好。图3表1参5

Braid river sandbody shape forecast by numeri-cal simulation method

An ASP flooding experiment was conducted on man-made rock model to simulate two-dimension vertical heterogeneous positive rhythm reservoir. The man-made rock model was made up of three single man-made rock samples which were connected parallelly. In the experiment, produced oil and water were measured separately. Base on the experimental results, a synthetic analysis was used to reveal the water cut differences, the produced fluid percent, oil recovery factor and vadose mechanism of the vertical areas befor...