Abstarct: Preservation of oil reserves as today's wealth and future heritage is an important and strategic imperative of the energy and macroeconomic sector of the country. These issues are realized with hybrid reservoir management with the aim of maximizing the profitability of reservoirs, maximizing incremental oil recovery and minimizing the cost of production. A significant number of the offshore reservoirs are shared between the Persian Gulf. For this reason, the importance of research, the production, and transfer of technology in the field of enhanced oil recovery, optimization and increase of production from these fields has become more important because the future value of oil and gas reserves, without taking into account the application of enhanced oil recovery methods, new exploration of oil and gas resources, and industry support through new resource technologies, is reduced dramatically. One of the most commonly used methods of enhanced oil recovery is the brine injection of a reservoir, which is injected into the reservoir using one or more brine injection wells in the reservoir formation and sweeping the remaining oil. This method is used in most of the major reservoirs in the world, including Iran's reservoirs, which are mostly heterogeneous and fractured reservoirs, and the efficiency of the swept in this type of reservoirs due to the low capillary pressure in the separated stone blocks by fracture is very low. Wettability alteration in these reservoirs by means of reducing the surface elasticity of the oil wet to neutral, in the best case of average water wet, increases the capillary pressure and water imbibition from the inside into the slab into the stone block, the efficiency water flooding by water causes the oil trap to be driven into the formation of a matrix. In this thesis, we have tried to by using decrease interfacial tension and surface tension between stone/water / oil in different time periods and type of oil, using a soaking method using a surfactant solution, using a steam soaking method or heating, increase the water flooding efficiency. In these investigations, it was concluded that the amount of residual oil reached its lowest level by increasing the soaking time, and the oil was also remarkable in this effect.