Abstract
The paper treats the problem of water injection into subsaturated reservoirs to describe their evolution in time. The reservoir, is considered a continuously stratified system with different rates of uniformity. The obtained results had show that in the case of a uniform reservoir there is a period in which, practically, it is produced only gas, but a high rates of uniformity and high viscosity of oil, the resaturating process continues in the oil-water production period. It shows too, that in case of the increased number of layers, the displacement with the mixture of the oil-water zone is possible to be approximated with the piston-like one.