سروش احمدی

The water injection process can improve the performance of the production operation by maintaining reservoir pressure. The decrease in rock permeability due to salt precipitation usually occurs by mixing formation and injection waters. One way to reduce the formation damage is the reduction of ion concentrations in the injection water. Low salinity water injection (LSWI) reduces the formation damage, and can turn the reservoir from oil-wet to water-wet. In this work, a reservoir model with four production wells and one injection well was utilized to analyze the recovery factor, total production rate, and water cut. The production was evaluated in periods. For the first 20 years, the production was carried out without water injection. Then, for 20 years, the water was injected at concentrations of 50000, 25000, 10000, 5000, and 4000 ppm. The simulation results showed the recovery factor after 20 years without water injection was about 28%. After water injection, the recovery factor was increased by 9.8% (at 50000 ppm) and 14.8% (at 4000 ppm). Also, the production rate was increased by decreasing the water salinity. The water cut was reduced by decreasing salinity and, as a result, oil production increased. The optimum salinity was 5000 ppm.