The regularities of oil displacement by water in different reservoir types of AB13 and AB2-3 formations of Samotlor field are reviewed. The influence of development scheme parameters on oil recovery efficiency is evaluated. The relationship is established between sweep efficiency and integrated parameter, incorporating all key geological-technological factors, which enables to forecast volumes of movable and remaining oil reserves for late stages of field development, and according to the correlation between constituent parameters, based on geological model, to carrie out geological-technological measures for improvement of oil recovery factor.