射孔完井渗流场的有限元分析

Finite element analysis of seepage field for perforating completion

魏臣兴 练章华 郭衍茹 丁士东 赵旭

中国石油渤海钻探工程技术研究院，天津 300475 西南石油大学油气藏地质及开发工程国家重点实验室，四川 成都 610500 中国石油化工股份有限公司石油工程技术研究院，北京 100101

Research Institute of Bohai Drilling Engineering Technology, CNPC, Tianjin 300475, China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China Research Institute of Petroleum Engineering Technology, SINOPEC, Beijing 100000, China

为优选元坝地区海相碳酸盐岩气藏射孔完井参数，在充分考虑真实天然气的偏差因子、密度及黏度随压力变化的基础上，建立了渗流数学模型，并利用COMSOL Multiphysics软件进行求解计算，得到射孔完井方式下近井壁的渗流场分布。文中从X平面提取若干条割线，进一步分析各割线处压力的分布特点；然后改变射孔完井的各个参数，建立有限元模型，计算出不同参数下射孔完井的产能比。计算结果表明，射孔完井渗流场中，从供给边界到井底压力为明显的“压降漏斗”趋势，与常规解析解趋势一致。在影响射孔完井产能的参数中，主要是孔深、孔密、孔径和相位角，其中孔深对产能的影响最大，其次是相位角。

In order to select the perforating completion parameters of marine facies carbonate gas reservoirs in Yuanba Area, based on the consideration of real gas deviation factor, density and the change of viscosity with pressure, the mathematical model of seepage flow is established. The model is solved to calculate using COMSOL Multiphysics software, getting the seepage field distribution of near wellbore under perforating completion. Several secant lines are extracted from X plane to further analyze the stress distribution characteristics of the secant lines. Through changing the parameters of perforating completion, this paper establishes the finite element model to calculate the productivity ratio of perforating completion at different parameters. The results show that the pressure change obviously shows as the cone of depression from supply boundary to hole bottom, being consistent with the trend of conventional analytical solution. In the parameters affecting the productivity of perforating completion, the most important parameters are phase angle, perforation density, perforation depth and perforation diameter. In them, perforation depth is the greatest influencing factor, followed by phase angle.

10.6056/dkyqt20140422