The chemical enhanced oil recovery (CEOR) process is introduced as one of the most effective methods for reducing the residual oil saturation through oil reservoirs. Because the chemical phase has a great potential for altering the reservoir rock and fluids properties. The main purpose of this study is a combination of low saline water (LSW) with surfactant and alkaline-surfactant to achieve maximum oil recovery by the combination of different mechanisms. In this work, the fluid–fluid and rock-fluid interactions were investigated by conducting several experimental techniques for two varied crude oil samples. Due to the high polarity of resin and asphaltene molecules, these two crude oil samples were divided into low-polar and high-polar samples. The optimum diluted seawater was used as LSW for both crude oil samples at 3000 ppm total dissolved solids. Based on obtained results from the interfacial tension (IFT) measurement tests and dynamic contact angle, using NaOH with LSW and AOS at critical micelle concentration (CMC) has a greater influence on reducing the IFT and altering the carbonate rock wettability from oil-wet to water-wet condition compared to Na2CO3. Adding only 100 ppm NaOH to the LSW-AOS(CMC) solution, the IFT values between an alkali-surfactant solution with low-polar and high polar crude samples were decreased from 0.43 and 1.33 mN/m to 0.21 and 0.55 mN/m, respectively. Moreover, the pH of LSW-AOS solution rises with the addition of NaOH to the solution and the surface charge moves toward a more negative charge based on the zeta potential results. This phenomenon increases the repulsion between surface charge and negatively charged polar components and, consequently desorption of polar components from the rock surface get improved. Furthermore, some in-situ surfactant (soap) generates by a reaction between NaOH and carboxylic acids and the creation of an ion pair between surfactants (AOS and Soap) and adsorbed polar groups which lead to the creation of a hybrid mechanism between LSW, AOS, and NaOH for changing the wettability from oil-wetness toward water-wetness. Therefore, the maximum oil recovery was achieved by flooding with LSW- AOS(1000 ppm)-NaOH (100 ppm) solution for both crude oil samples, high polar and low polar cured oil samples, that obtain 42.24 % and 71.67% recovery factors, respectively. Moreover, coreflooding results confirmed the micromodel results in the presence of initial water saturation at high temperature condition.