Chemical flooding has great potential for enhancing heavy oil recovery, especially for reservoirs in which thermal methods are not suitable. Recently, it has been recognized that lower recovery of heavy oil by water flooding is attributed to an inefficient sweep in the pore scale and not the residual oil in the swept region for conventional oil. This paper presents a novel chemical flooding for enhanced heavy oil recovery, focusing on this idea. In this method, an alkaline solution including an alkaline earth metal ion is injected into heavy oil that possesses acidic components. Here, Ca(OH)(2) solution was used as an alkaline solution including an alkaline earth metal ion. Further, a heavy oil model containing an acid component, i.e., a paraffin oil including a fatty acid, was used. Metallic soap is generated by chemical reaction precipitates at the oil-water interface, which behaves as a viscoelastic material. The viscoelastic material in the pore blocks the preferentially swept region and improves the sweep efficiency. To maximize its effect, we propose a method involving the injection of Ca(OH)(2) solution prior to water flooding as opposed to the conventional methods, wherein the chemicals are injected after water flooding. Also, we propose a continuous Ca(OH)(2) injection method, where the cumulative oil recovery reached around 55% initial oil in place (IOIP%), which was much larger than that of water flooding (33 IOIP%) and conventional alkaline flooding (35 IOIP%). In addition, we show that the novel flooding method proposed can be applied to heavy oil reservoirs after water flooding. Furthermore, the novel flooding enhanced heavy oil recovery in the wide range of the concentration of acid tested. Additionally, we find that the viscoelasticity is maintained up to 80 degrees C. The proposed method benefits from the adversity of the precipitate formed by a divalent ion (as a result of using polymer, surfactant, or alkali), which is commonly regarded as an undesirable factor for chemical flooding. This method is surfactant- and polymer-free. On the basis of these considerations, this study introduces a novel chemical flooding method for enhanced recovery of heavy oil, which is inexpensive, high-divalent-ion-tolerant, high-temperature-tolerant, and energy-saving.