In this study, the description of Enhance Oil Recovery effectivity (EOR) of surfactant denominated reagent A, at the secondary waterflooding process for heavy oil recovery from fractured-porous carbonate core samples were investigated experimentally. For this experiment have been selected two cores, 14,75 cm long and 3 cm diameter were stacked in a long 3D confining core holder. In the first step, cores have been saturated by brine. In the second step, cores have been saturated of heavy oil through the water-saturated core sample for two-phase saturation. In the third step, we provided the injecting of water through the core sample for measuring oil recovery factor (by cold water 20ºC) simulating the primary recovery at these conditions. In the fourth step, was injected of 2 pore volumes of Reagent A through the core sample for measuring oil recovery factor (by reagent A) and simulating the slug. In the fifth step and final, was injected water through the core sample for measuring full oil recovery factor (by cold water) after slug of Reagent A. In the course of experiments, oil and water productions, pressure and temperatures of system were monitored and regulated carefully.