多区非均质油藏的有限元法理论分析

The theoretical analysis of heterogeneous reservoir with muti-zones by using finite element method

建立了单相流体在非均质油藏中、在不稳定渗流条件下的有限元方程,同时考虑了井筒储存效应和表皮效应的影响。将井壁视为内边界,在空间上用任意四边形单元对求解区域进行剖分,在时间上用向后差分法进行离散。用二区非均质油藏的解析解对方法进行了验证,而后对三区非均质油藏和四区非均质油藏进行了模拟分析,说明用有限元法模拟分析多区非均质油藏是准确、方便的。实际上,本模拟器可以适用于任意非均质油藏。

In this paper, a finite element method is established under the condition of unsteady flow in the heterogeneous reservoir taking into account the affection of the well bore storage effect and skin effect. Treat the well face as internal boundary. Section the region with quadrilateral grid. In the time domain, the equations are dispersed by using backward difference method. Validate the equations and the computation program with analytical solution of two zones heterogeneous reservoir. The case of three-zone and four-zone heterogeneous reservoir were simulated, It is shown that the finite element method is accurate and convenient to simulate heterogeneous reservoir with mutlti-zones. In fact, this numerical simulation can be applied in any heterogeneous reservoir.