When we develop petroleum and natural gas reservoirs, we can see a lot of dual-porosity reservoirs with both pores and fractures. Many researchers have studied characteristics of fluid flow in dual-porosity reservoirs with the ideal outer boundary (infinite boundary, closed boundary or constant pressure boundary) but nobody has considered dual-porosity model with the elastic outer boundary (EOB) reflecting the real condition. So there could be large errors in analyzing well-test data for dual-porosity model. In this paper, we establish a percolation model for dual-porosity reservoirs with the EOB and consider the skin factor and wellbore storage. And we obtain its solution in Laplace space by introducing the effective well radius and applying the Laplace transformation. An approximation in Laplace space is also derived by using an asymptotic formula of I₀(x) and I₁(x). By using Stehfest numerical inversion of Laplace transformation, the solution in the real space is obtained. We compare this model to homogeneous model with the EOB and conventional dual-porosity model, respectively. Comparison results show that the conventional outer boundary conditions are three special cases of the EOB and homogeneous model with the EOB is a special case of dual-porosity model with the EOB. Flow characteristics are analyzed and it is shown that the EOB affects analysis of well-test data through simulation. This study may improve the accuracy of well-test analysis for dual-porosity reservoir.

我们在开发油气藏时，可以看到很多孔缝双孔的储层。许多研究人员研究了具有理想外边界（无限边界、封闭边界或恒压边界）的双孔隙储层中流体流动特征，但没有人考虑使用弹性外边界（EOB）来反映实际情况的双孔隙模型。因此，双孔隙度模型试井数据分析可能存在较大误差。在本文中，我们建立了具有EOB的双孔隙储层渗流模型，并考虑了表皮因素和井筒储量。我们通过引入有效井半径并应用拉普拉斯变换在拉普拉斯空间中获得了它的解。I ₀ ( x ) 和I ₁ ( x )。通过使用拉普拉斯变换的Stehfest数值反演，得到了实空间中的解。我们分别将该模型与具有 EOB 和传统双孔隙度模型的均质模型进行比较。对比结果表明，常规外边界条件是EOB的三种特例，带EOB的均质模型是带EOB的双孔隙度模型的特例。分析了流动特性，通过模拟表明EOB影响试井数据的分析。该研究可提高双孔储层试井分析的准确性。