关键词: 垂直裂缝井, 两相流体, 活动边界, 非线性方程, 有限差分法, 开发指标

Abstract: Hydraulic parting,which can form a symmetrical and vertical plane of fracture in the ormation thaft surrounds a well is an effective measure of increasing production.A vertical fractured well can bring out two-dimensional flow in the direction of normals of developing ellipse-conjugate equal-pressure ellipse and hyperbola streamline bunches whose focal points are the two ends of the fracture when it works.A mathematical model of oil and water two-phase fluid flow in the normal direction of the ellipses,which is a nonlinear equation with a moving boundary is established according to concepts of turbulent ellipses and equivalent developing regulations.Characteristic solution and finite difference solution to the model are derived respectively and water saturation distribution curves are presented.And the variation of regularity moving boundary is found.Results showed good agreement between the characteristic solution and finite difference solution.Moreover,formula of water-flooding development indexes for vertical fractured wells are derived. Laws of change of production and pressure difference with time are recognized.The paper provides numerical simulation, dynamic analysis and prediction of water-flooding development of oilfields in the case of vertical fractured wells with theoretical basis.

Key words: vertical fractured well, two-phase fluid, moving boundary, nonlinear equation, finite difference method, development index