Offshore oil fields are characterized by high crude oil viscosity, high salinity content, and significant reservoir heterogeneity. Additionally, they exhibit engineering features such as high injection flow rates and completion techniques involving wireline screen pipe gravel packing. These conditions collectively pose challenges for the application of chemical flooding technologies. To address these challenges, low-molecular-weight acrylamide-based copolymer flooding agents-designated HOA-1, HOA-2, and HOA-3 were developed. These agents demonstrate favorable injectivity, high shear and thermal stability, and effective interfacial activity among oil, water, and rock, with progressively increasing functional monomer content across the series. The transport behavior of these agents through porous media, as well as the interactions among oil, water, agent, and rock, were systematically investigated using membrane filtration, dual-polarization interferometry (DPI), atomic force microscopy (AFM) droplet analysis, and core displacement experiments. Experimental results indicate that with increasing functional monomer content in HOA agents: (1) the transportability of HOA-1, HOA-2, and HOA-3 through 0.2?μm pores decreases sequentially; however, when pore throat size exceeds 0.2?μm, no significant difference in transport performance is observed; (2) adsorption at the oil–water interface increases progressively-from 2.12?ng/mm2 to 3.94?ng/mm2-and the adsorption mechanism transitions from monolayer to multilayer formation; (3) adsorption on quartz sand surfaces decreases gradually-from 0.79?mg/g to 0.52?mg/g-following the Freundlich isothermal adsorption model; and (4) adhesion forces between the HOA agents and crude oil increase significantly-from 5.1?nN to 18.3?nN-resulting in enhanced displacement efficiency of homogeneous cores, which rises from 18.54% to 42.32%. In the displacement experiments using heterogeneous cores, the EOR increments of the three HOAs showed a successive increase, rising from 13.67% to 20.33%.