气井非达西流射孔完井的有限元数值模拟研究

A NUMERICAL SIMULATION OF THE PERFORMANCE OFPERFORATION IN A GAS WELL INCLUDING NON-DARCY EFFECTS BY MEANS OF FINITE ELEMENT METHOD

根据气井射孔非达西流的偏微分方程和边界条件,通过建立离散化的有限元模型,采用迭代法准确求出各剖分单元的传导系数,获得了气井非达西流射孔完井在不同参数下的产率比和表皮系数。文中全面分析了12个影响因素与气井产率比的关系,讨论了各因素影响的相对重要性层次。研究结果得到的气井射孔规律与油井大不相同,许多规律为首次发现。

Although many investigation have performed to determine the performance of perforation in an oil well, the study on The performance of perforation in a gas well is fairly poor because of the complexities in the simulation of perforation space, compressibility of gas and non-darcy flow. Based on the partial differential equations and boundary conditions of non-darcy gas flow through perforations and formation,a finite element model was built in this paper. The solution of transfer coefficient Txx, Tyy, Tzz with nondarcy flow in each element was discussed. This paper analyzes the effects of twelve factors on the productivity ratio of a perforated gas well, including factors such as perforation depth, perforation diameter, shot density, phase angle, crushed zone radius, degree of, crushed damage radius of damaged zone, degree of damage, well radius, drawdown, formation permeability and anisotropy. The relative importance of these twelve factors is given. Results of this study show that the performance of a perforation in a gas well differs greatly from that in an oil well. Many properties of perforation in gas well found by this paper are reported for the first time.