【摘要】 建立了复杂外边界裂缝性低渗透油藏渗流数学模型,使用迦辽金法推导模型的有限元方程。考虑井筒存储和表皮效应的影响,将井壁视为内边界、外边界封闭或定压,或为同时含封闭和定压边界的混合边界;使用Delaunay三角形对求解区域剖分,时间采用隐式方式离散;编制程序求解有限元方程得到不同时间的油藏压力分布,绘制不同类型边界的地层中一口井及地层中不同位置一口井的试井理论曲线;分析了启动压力梯度、外边界及井位置对井底压力的影响。结果表明有限元法处理复杂外边界可以取得较好效果。更多还原

【Abstract】 Flow mathematic model of low-permeability fractured reservoir with complex outer-boundary was established and the finite-element equation of model was derived using Galerkin method.Based on the wellbore storage effect and skin effect,the wellbore was considered as inner boundary and the outer boundary was closed,constant pressure,or mixed boundary with both closed and constant pressure boundary.The domain was decomposed using Delaunay triangular mesh.The time was discretized using implicit difference scheme.Computer program was written and finite-element equation program was worked out to obtain the pressure distribution of reservoir in different time step.Theoretical well testing curves of bottom-hole pressure of a well in formation with outer boundary of different type and a well in different location were drawn.The influences of starting pressure gradient,outer boundary and location of well on the bottom-hole pressure were analyzed.The results show that the finite-element method can deal with the complex outer boundary effectively.更多还原