Objective By endowing polymer microspheres with a fluorescent characteristic that enables them to have tracer performance, the actual situation of adsorption, retention, and migration of polymer microspheres in the formation can be clearly understood based on the detection of the produced liquid. However, a difficult problem that needs to be solved urgently is how to maximize the displacement ability of keeping the original microspheres with the effective integration of fluorescent materials and polymer microspheres.

Methods The preparation of fluorescent microspheres was achieved through copolymerization reaction using ordinary core-shell microspheres with cationic functional monomers, acrylamide, and other main components as carriers and carbon quantum dots as fluorescent materials. The fluorescence intensity was measured and a comparative experiment of Zeta potential, hydration expansion, and sealing performance was carried out.

Results The fluorescence yield rate of carbon quantum dots was high, with a minimum detection limit of 0.05%; The Zeta potential data demonstrated that the fluorescent monomer was successfully fixed to the core layer of the microspheres, ensuring effective fusion of the fluorescent material with the prototype microspheres; The difference in sealing efficiency between fluorescent microspheres and ordinary core-shell microspheres was within 3%, and the hydration expansion and sealing performance of them were basically same.

Conclusions The introduction of the carbon quantum dot fluorescent material into the core layer has not changed the characteristics of the polymer microspheres, and the detection limit value is low, which is expected to be used in subsequent field applications.