关键词: 多重网格, 区域分解, 快速自适应组合网格, 子域, 油藏模拟

Abstract: As an update computation method, Fast Adaptive Composite Grid has brought to the field of reservoir numerical simulation more and more attention.In fact, the method which based on multigrid principal, is a kind of domain decomposition method.Many problems will be caused when FAC was used in reservoir simulation, this paper raised a Flexible Fast Adaptive Composite Grid to improve FAC. First, the grid refinement is based on every grid block in FFAC and abnormal linking skills are used to deal with the joined grids with different size, so FFAC can simulate any shape subdomain; in addition, it break down the barrier which every subdomain can`t touch each other.Then it can simulate the frontier of flooding with the dynamic grid refinements easily. Second, FFAC can alternatively use direct solver or relaxation solver according to the practical situation.Third,FFAC sets the refinement cells and coarse cells through the inlaying way, which can decrease the number of grids greatly and need less memory.Fourth, FFAC can set integrid value by attaining the residues of the composite grid instead of FAC way that uses interpolation and local restriction operators as multigrid techniques when dealing with such questions as interface interpolation and conservation objectives.FFAC overcomes the shortcomings of FAC and provides a flexible ides for reservoir numerical simulation technology.

Key words: multigrid, domain decomposition, fast adaptive composite grid, subdomain, reservoir simulation