Waterflooding and Enhanced Oil Recovery (EOR) techniques are known to be viable options in oil recovery. Operators worldwide implement these techniques to maintain reservoir pressure, increase oil recovery, and prolong the overall life cycle of the production area. While each method theoretically behaves according to a specific physical phenomenon, how it manifests in real life differs from one field to another. Thus, experimenting with these techniques through lab work and simulations before their application in the field is crucial to achieving the desired outcome and optimizing the injection process by how, when, where, and what to inject. One method for studying such fluid movement is in the microfluidic genre, implementing a Lab on a chip (LOC) approach because it allows the measurement and the visualization of the physical phenomena at a detailed level on the pore scale. LOC allows altering flow configurations and parameters to understand their effects on fluid displacement and flow regimes fully. For this reason, this thesis is based on the LOC method. Several chip designs with varying properties, such as aspect ratio and distance between pores, were used. Fluids with different chemical compositions, such as surfactant, alkaline solutions, and distilled water, were injected at different rates. Doing so allowed us to see how the injected fluid's compositions affect the flow and how the available pore design aids or hinders successful recovery. In other words, we analyzed the situation from two points of view: the manipulation of (a) the injected fluid and (b) the shape of the flow passages. Thus, we can develop a general theory of what to expect when details about the pore structure are known. Our experiments were analyzed at three-time intervals: first contact displacement (i.e., when the injected mixture first meets the displaced phase), during continuous displacement, and at the final stages. The analysis included front shape, remaining oil saturation, emulsion formation, and velocity calculation. Our results for low-rate fluid injection into a decane-filled pore system prove that aspect ratio affects our studied parameters. We are revealing that with an increasing aspect ratio (for the constant distance between pores), the front velocity and stability and the amount of remaining oil increase. Altering the salinity of the injected surfactant similarly affects these parameters and the degree of solubilization of decane in water.