Similarity theory of recovery percent and water cut in water flooding reservoir;

A φ-fanction method for estimating distribution of residual oil saturation in water drive reservoir;

If the reservoir pressure wasn't properly maintained in the process of oil development,the character of fluid flow through porous medium will be changed,the recovery rate and the benefit of developing would obviously be declined for many types of reservoirs,such as water drive reservoir,high gas/oil ratio reservoir and stress-sensitive reservoir.

On the basis of obtaining solution of mathematical model,and taking into account the influence of wellbore storage and skin effect and the strength of water-drive,the paper calculated typical curves of pressure and pressure derivative for oil well in water-drive oil reservoir,analyzed the characteristic of pressure behavior,these works provided theory basis for well test.

The variation rule oil-water relative permeability and influence factors of water-drive reservoir under DC electric field are investigated by experiments of unsteady-state oil-water relative permeability.