裂缝性气水两相地层井筒组合数值模拟

气水井试井对天然气开发具有重大意义。借助数值模拟方法了解地下气流和水流的变化，对于提高采收率是极为重要的。通常的数值模拟中仅考虑了储层的渗流动态，而把井筒视为线汇处理，这不能准确的反映出井筒和储层之间的相互影响。建立了气水两相组合模型，借助有限体积法导出了组合模型的离散方程，并讨论了求解的边界条件。实算表明了这种方法能更有效地反映出试井过程中的各种现象。

A Combined Numerical Simulation for Transient Two-Phase Flows of Gas and Water in the Wellbore/Reservoir with Fracture

Analysis of two-phase flow of gas and water in wellbore/reservoir has important significance for natural gas exploitation. During the production, natural gas always flows from reservoir to wellbore. But, the numerical simulations in the past, which generally omitted some inner relations between reservoir and wellbore, respectively. This method cannot precisely describe the change of physical state in whole system. In the paper, we combine transient two-phase model of gas and water in wellbore with nonhomogeneous multiphase seepage model in reservoir to discuss the problem of well test. The combined model considers mutual action between wellbore and reservoir. In computation, the discrete simultaneous equations are solved. The numerical results show that the method can effectively reflect various physical phenomena in well test.