基于解相似结构的复合油藏渗流模型研究

Study on percolation model of composite media reservoir based on similar structure of solution

笔者建立了考虑有效井径和井筒储集条件下的复合油藏渗流模型。利用Laplace变换方法,在Laplace空间中得到了变流率情形下不同外边界条件下的储层压力和井底压力准确解。根据相似结构理论,定义了相似核函数,相似核函数与渗流定解方程的基础解系及外边界条件有关,不同外边界条件对应于不同相似核函数,且与内边界务件无关;发现3种外边界条件下的解式具有相似结构,为编制试井分析软件带来了极大便利,对油气藏渗流规律理论研究具有重要意义。

The percolation model of composite media reservoir is established in this paper, which considers the effective wellbore radius and wellbore storage. By using Laplace transform, the exact solutions of reservoir pressure and bottom hole pressure are obtained under different boundary conditions in Laplace space. According to the theory of similar structure, this paper defines the kernel functions which are only in connection with the basic solution set of fixed solution problem and outer boundary conditions, what＇s more, different outer boundary conditions correspond to different similar kernel functions, having nothing to do with inner boundary conditions. There is a similar structure among the solutions under three outer boundaries. Furthermore, this study supplies a lot of conveniences for programming well test analysis software and has significance to the theoretical study of the oil-gas percolation law.