Abstract:

The dissolved pores in fracture and vugtype reservoirs in Tahe Oilfield can be classified into small dissolved pore space and vugs, some of the vugs are not filled, and in the unfilled vugs, there not exists porous media, the fluids belongs to free flow, the law of flow is accordance with NavierStokes equation, there are free flow region and the region of flow through porous media, the law of law is accordance with DarcyStokes coupling mode. Aimed at the characteristics of fluids in Tahe Oilfield, the DarcyStokes mode, which is existing and used to describe the flow of single phase uncompressible fluids, is expanded to lightly compressible fluids of two phases, and also, according to the little pressure difference in the unfilled vugs, the oil water momentum conservation equation is simplified, the obtained momentum conservation equation is same as the one of uncompressible fluids in pattern, but the density and viscosity of fluids are the function of pressure. In the mode, the BeaversJosephSaffman boundary condition is introduced, and the condition is expanded to two phases flow. DarcyStokes mode is applied in numerical well testing, the result indicates the interpretation of NavierStokes mode is more close to the interpretation of geological mode expected by 3D seismic survey, despite of good matching effect being obtained from dual media flowing through porous media mode and NavierStokes mode.

Key words: Tahe Oilfield, DarcyStokes, two phases flow, fracture, vug