Rheology Properties and Plugging Performance of Fluorescent Polyacrylamide Microspheres in Fractures

Polyacrylamide microspheres have recently drawn great attention in conformance control due to their advantages over traditional gel treatments. One important question that has been raised is whether the tiny particles can be produced from production wells. However, current products are difficult to use for detecting fluids generated by production wells. In this paper, the fluorescent polyacrylamide microspheres were successfully synthesized; they can emit blue fluorescence under ultraviolet irradiation. Their swelling property, fluorescence characteristics, rheology property, creep-recovery property, and plugging performance were evaluated in the laboratory. The results indicated that the microspheres could emit blue fluorescence under ultraviolet irradiation after passing through a fracture model. Their creep-recovery ability after deformation was very high, and their elastic recovery rate extended to 94.1%, which suggests that the microspheres almost recover to their original shape and size after deformation. The transparent fracture model plugging test shows that the microspheres can migrate and plug a fracture with a width of 0.3 mm, which is much smaller than the diameter of the microspheres.